title: Antenna (radio)

text: The radio signal's electrical component induces a voltage in the conductor. This causes an electrical current to begin flowing in the direction of the signal's instantaneous field. When the resulting current reaches the end of the conductor, it reflects, which is equivalent to a 180-degree change in phase. If the conductor is of a wavelength long, current from the feed point will undergo 90 degree phase change by the time it reaches the end of the conductor, reflect through 180 degrees, and then another 90 degrees as it travels back. That means it has undergone a total 360 degree phase change, returning it to the original signal. The current in the element thus adds to the current being created from the source at that instant. This process creates a standing wave in the conductor, with the maximum current at the feed.


title: Antenna (radio)

text: The ordinary half-wave dipole is probably the most widely used antenna design. This consists of two  wavelength elements arranged end-to-end, and lying along essentially the same axis (or "collinear"), each feeding one side of a two-conductor transmission wire. The physical arrangement of the two elements places them 180 degrees out of phase, which means that at any given instant one of the elements is driving current into the transmission line while the other is pulling it out. The monopole antenna is essentially one half of the half-wave dipole, a single  wavelength element with the other side connected to ground or an equivalent ground plane (or "counterpoise"). Monopoles, which are one-half the size of a dipole, are common for long-wavelength radio signals where a dipole would be impractically large. Another common design is the folded dipole which consists of two (or more) half-wave dipoles placed side by side and connected at their ends but only one of which is driven.


title: Antenna (radio)

text: The standing wave forms with this desired pattern at the design operating frequency, "f", and antennas are normally designed to be this size. However, feeding that element with "3 f" (whose wavelength is that of "f") will also lead to a standing wave pattern. Thus, an antenna element is "also" resonant when its length is of a wavelength. This is true for all odd multiples of  wavelength. This allows some flexibility of design in terms of antenna lengths and feed points. Antennas used in such a fashion are known to be "harmonically operated". Resonant antennas usually use a linear conductor (or "element"), or pair of such elements, each of which is about a quarter of the wavelength in length (an odd multiple of quarter wavelengths will also be resonant). Antennas that are required to be small compared to the wavelength sacrifice efficiency and cannot be very directional. Since wavelengths are so small at higher frequencies (UHF, microwaves) trading off performance to obtain a smaller physical size is usually not required.


title: Antenna (radio)

text: The quarter-wave elements imitate a series-resonant electrical element due to the standing wave present along the conductor. At the resonant frequency, the standing wave has a current peak and voltage node (minimum) at the feed. In electrical terms, this means the element has minimum reactance, generating the maximum current for minimum voltage. This is the ideal situation, because it produces the maximum output for the minimum input, producing the highest possible efficiency. Contrary to an ideal (lossless) series-resonant circuit, a finite resistance remains (corresponding to the relatively small voltage at the feed-point) due to the antenna's radiation resistance as well as any actual electrical losses.


title: Antenna (radio)

text: Recall that a current will reflect when there are changes in the electrical properties of the material. In order to efficiently transfer the received signal into the transmission line, it is important that the transmission line has the same impedance as its connection point on the antenna, otherwise some of the signal will be reflected backwards into the body of the antenna; likewise part of the transmitter's signal power will be reflected back to transmitter, if there is a change in electrical impedance where the feedline joins the antenna. This leads to the concept of impedance matching, the design of the overall system of antenna and transmission line so the impedance is as close as possible, thereby reducing these losses. Impedance matching is accomplished by a circuit called an antenna tuner or impedance matching network between the transmitter and antenna. The impedance match between the feedline and antenna is measured by a parameter called the standing wave ratio (SWR) on the feedline.


title: Antenna (radio)

text: Consider a half-wave dipole designed to work with signals with wavelength 1 m, meaning the antenna would be approximately 50 cm from tip to tip. If the element has a length-to-diameter ratio of 1000, it will have an inherent impedance of about 63 ohms resistive. Using the appropriate transmission wire or balun, we match that resistance to ensure minimum signal reflection. Feeding that antenna with a current of 1 Ampere will require 63 Volts, and the antenna will radiate 63 Watts (ignoring losses) of radio frequency power. Now consider the case when the antenna is fed a signal with a wavelength of 1.25 m; in this case the current induced by the signal would arrive at the antenna's feedpoint out-of-phase with the signal, causing the net current to drop while the voltage remains the same. Electrically this appears to be a very high impedance. The antenna and transmission line no longer have the same impedance, and the signal will be reflected back into the antenna, reducing output. This could be addressed by changing the matching system between the antenna and transmission line, but that solution only works well at the new design frequency.


title: Antenna (radio)

text: The result is that the resonant antenna will efficiently feed a signal into the transmission line only when the source signal's frequency is close to that of the design frequency of the antenna, or one of the resonant multiples. This makes resonant antenna designs inherently narrow-band: Only useful for a small range of frequencies centered around the resonance(s).


title: Antenna (radio)

text: It is possible to use simple impedance matching techniques to allow the use of monopole or dipole antennas substantially shorter than the or  wave, respectively, at which they are resonant. As these antennas are made shorter (for a given frequency) their impedance becomes dominated by a series capacitive (negative) reactance; by adding an appropriate size “"loading coil"” – a series inductance with equal and opposite (positive) reactance – the antenna's capacitive reactance may be cancelled leaving only a pure resistance.


title: Antenna (radio)

text: Sometimes the resulting (lower) electrical resonant frequency of such a system (antenna plus matching network) is described using the concept of "electrical length", so an antenna used at a lower frequency than its resonant frequency is called an "electrically short antenna"


title: Antenna (radio)

text: For example, at 30 MHz (10 m wavelength) a true resonant  wave monopole would be almost 2.5 meters long, and using an antenna only 1.5 meters tall would require the addition of a loading coil. Then it may be said that the coil has lengthened the antenna to achieve an electrical length of 2.5 meters. However, the resulting resistive impedance achieved will be quite a bit lower than that of a true  wave (resonant) monopole, often requiring further impedance matching (a transformer) to the desired transmission line. For ever shorter antennas (requiring greater "electrical lengthening") the radiation resistance plummets (approximately according to the square of the antenna length), so that the mismatch due to a net reactance away from the electrical resonance worsens. Or one could as well say that the equivalent resonant circuit of the antenna system has a higher Q factor and thus a reduced bandwidth, which can even become inadequate for the transmitted signal's spectrum. Resistive losses due to the loading coil, relative to the decreased radiation resistance, entail a reduced electrical efficiency, which can be of great concern for a transmitting antenna, but bandwidth is the major factor that sets the size of antennas at 1 MHz and lower frequencies.


title: Antenna (radio)

text: The radiant flux as a function of the distance from the transmitting antenna varies according to the inverse-square law, since that describes the geometrical divergence of the transmitted wave. For a given incoming flux, the power acquired by a receiving antenna is proportional to its "effective area". This parameter compares the amount of power captured by a receiving antenna in comparison to the flux of an incoming wave (measured in terms of the signal's power density in watts per square metre). A half-wave dipole has an effective area of about 0.13λ seen from the broadside direction. If higher gain is needed one cannot simply make the antenna larger. Due to the constraint on the effective area of a receiving antenna detailed below, one sees that for an already-efficient antenna design, the only way to increase gain (effective area) is by "reducing" the antenna's gain in another direction.


title: Antenna (radio)

text: If a half-wave dipole is not connected to an external circuit but rather shorted out at the feedpoint, then it becomes a resonant half-wave element which efficiently produces a standing wave in response to an impinging radio wave. Because there is no load to absorb that power, it retransmits all of that power, possibly with a phase shift which is critically dependent on the element's exact length. Thus such a conductor can be arranged in order to transmit a second copy of a transmitter's signal in order to affect the radiation pattern (and feedpoint impedance) of the element electrically connected to the transmitter. Antenna elements used in this way are known as passive radiators.


title: Antenna (radio)

text: A Yagi–Uda array uses passive elements to greatly increase gain in one direction (at the expense of other directions). A number of parallel approximately half-wave elements (of very specific lengths) are situated parallel to each other, at specific positions, along a boom; the boom is only for support and not involved electrically. Only one of the elements is electrically connected to the transmitter or receiver, while the remaining elements are passive. The Yagi produces a fairly large gain (depending on the number of passive elements) and is widely used as a directional antenna with an antenna rotor to control the direction of its beam. It suffers from having a rather limited bandwidth, restricting its use to certain applications.


title: Antenna (radio)

text: Rather than using one driven antenna element along with passive radiators, one can build an array antenna in which multiple elements are "all" driven by the transmitter through a system of power splitters and transmission lines in relative phases so as to concentrate the RF power in a single direction. What's more, a phased array can be made "steerable", that is, by changing the phases applied to each element the radiation pattern can be shifted "without" physically moving the antenna elements. Another common array antenna is the log-periodic dipole array which has an appearance similar to the Yagi (with a number of parallel elements along a boom) but is totally dissimilar in operation as all elements are connected electrically to the adjacent element with a phase reversal; using the log-periodic principle it obtains the unique property of maintaining its performance characteristics (gain and impedance) over a very large bandwidth.


title: Antenna (radio)

text: When a radio wave hits a large conducting sheet it is reflected (with the phase of the electric field reversed) just as a mirror reflects light. Placing such a reflector behind an otherwise non-directional antenna will insure that the power that would have gone in its direction is redirected toward the desired direction, increasing the antenna's gain by a factor of at least 2. Likewise, a corner reflector can insure that all of the antenna's power is concentrated in only one quadrant of space (or less) with a consequent increase in gain. Practically speaking, the reflector need not be a solid metal sheet, but can consist of a curtain of rods aligned with the antenna's polarization; this greatly reduces the reflector's weight and wind load. Specular reflection of radio waves is also employed in a parabolic reflector antenna, in which a "curved" reflecting surface effects focussing of an incoming wave toward a so-called feed antenna; this results in an antenna system with an effective area comparable to the size of the reflector itself. Other concepts from geometrical optics are also employed in antenna technology, such as with the lens antenna.


title: Antenna (radio)

text: The antenna's power gain (or simply "gain") also takes into account the antenna's efficiency, and is often the primary figure of merit. Antennas are characterized by a number of performance measures which a user would be concerned with in selecting or designing an antenna for a particular application. A plot of the directional characteristics in the space surrounding the antenna is its "radiation pattern".


title: Antenna (radio)

text: The frequency range or "bandwidth" over which an antenna functions well can be very wide (as in a log-periodic antenna) or narrow (as in a small loop antenna); outside this range the antenna impedance becomes a poor match to the transmission line and transmitter (or receiver). Use of the antenna well away from its design frequency affects its radiation pattern, reducing its directive gain.


title: Antenna (radio)

text: Generally an antenna will not have a feed-point impedance that matches that of a transmission line; a matching network between antenna terminals and the transmission line will improve power transfer to the antenna. A non-adjustable matching network will most likely place further limits the usable bandwidth of the antenna system. It may be desirable to use tubular elements, instead of thin wires, to make an antenna; these will allow a greater bandwidth. Or, several thin wires can be grouped in a "cage" to simulate a thicker element. This widens the bandwidth of the resonance.


title: Antenna (radio)

text: Amateur radio antennas that operate at several frequency bands which are widely separated from each other may connect elements resonant at those different frequencies in parallel. Most of the transmitter's power will flow into the resonant element while the others present a high impedance. Another solution uses "traps", parallel resonant circuits which are strategically placed in breaks created in long antenna elements. When used at the trap's particular resonant frequency the trap presents a very high impedance (parallel resonance) effectively truncating the element at the location of the trap; if positioned correctly, the truncated element makes a proper resonant antenna at the trap frequency. At substantially higher or lower frequencies the trap allows the full length of the broken element to be employed, but with a resonant frequency shifted by the net reactance added by the trap.


title: Antenna (radio)

text: The bandwidth characteristics of a resonant antenna element can be characterized according to its "" where the resistance involved is the radiation resistance, which represents the emission of energy from the resonant antenna to free space.


title: Antenna (radio)

text: The ' of a narrow band antenna can be as high as 15. On the other hand, the reactance at the same off-resonant frequency of one using thick elements is much less, consequently resulting in a ' as low as 5. These two antennas may perform equivalently at the resonant frequency, but the second antenna will perform over a bandwidth 3 times as wide as the antenna consisting of a thin conductor.


title: Antenna (radio)

text: Antennas for use over much broader frequency ranges are achieved using further techniques. Adjustment of a matching network can, in principle, allow for any antenna to be matched at any frequency. Thus the small loop antenna built into most AM broadcast (medium wave) receivers has a very narrow bandwidth, but is tuned using a parallel capacitance which is adjusted according to the receiver tuning. On the other hand, log-periodic antennas are "not" resonant at any single frequency but can (in principle) be built to attain similar characteristics (including feedpoint impedance) over any frequency range. These are therefore commonly used (in the form of directional log-periodic dipole arrays) as television antennas.


title: Antenna (radio)

text: Gain is a parameter which measures the degree of directivity of the antenna's radiation pattern. A high-gain antenna will radiate most of its power in a particular direction, while a low-gain antenna will radiate over a wide angle. The "antenna gain", or "power gain" of an antenna is defined as the ratio of the intensity (power per unit surface area) formula_1 radiated by the antenna in the direction of its maximum output, at an arbitrary distance, divided by the intensity formula_2 radiated at the same distance by a hypothetical isotropic antenna which radiates equal power in all directions. This dimensionless ratio is usually expressed logarithmically in decibels, these units are called "decibels-isotropic" (dBi)


title: Antenna (radio)

text: A second unit used to measure gain is the ratio of the power radiated by the antenna to the power radiated by a half-wave dipole antenna formula_4; these units are called "decibels-dipole" (dBd)


title: Antenna (radio)

text: Since the gain of a half-wave dipole is 2.15 dBi and the logarithm of a product is additive, the gain in dBi is just 2.15 decibels greater than the gain in dBd


title: Antenna (radio)

text: High-gain antennas have the advantage of longer range and better signal quality, but must be aimed carefully at the other antenna. An example of a high-gain antenna is a parabolic dish such as a satellite television antenna. Low-gain antennas have shorter range, but the orientation of the antenna is relatively unimportant. An example of a low-gain antenna is the whip antenna found on portable radios and cordless phones. Antenna gain should not be confused with amplifier gain, a separate parameter measuring the increase in signal power due to an amplifying device placed at the front-end of the system, such as a low-noise amplifier.


title: Antenna (radio)

text: The "effective area" or effective aperture of a receiving antenna expresses the portion of the power of a passing electromagnetic wave which the antenna delivers to its terminals, expressed in terms of an equivalent area. For instance, if a radio wave passing a given location has a flux of 1 pW / m (10 Watts per square meter) and an antenna has an effective area of 12 m, then the antenna would deliver 12 pW of RF power to the receiver (30 microvolts RMS at 75 ohms). Since the receiving antenna is not equally sensitive to signals received from all directions, the effective area is a function of the direction to the source.


title: Antenna (radio)

text: Due to reciprocity (discussed above) the gain of an antenna used for transmitting must be proportional to its effective area when used for receiving. Consider an antenna with no loss, that is, one whose electrical efficiency is 100%. It can be shown that its effective area averaged over all directions must be equal to , the wavelength squared divided by . Gain is defined such that the average gain over all directions for an antenna with 100% electrical efficiency is equal to 1. Therefore, the effective area in terms of the gain in a given direction is given by:


title: Antenna (radio)

text: For an antenna with an efficiency of less than 100%, both the effective area and gain are reduced by that same amount. Therefore, the above relationship between gain and effective area still holds. These are thus two different ways of expressing the same quantity. is especially convenient when computing the power that would be received by an antenna of a specified gain, as illustrated by the above example.


title: Antenna (radio)

text: The radiation pattern of an antenna is a plot of the relative field strength of the radio waves emitted by the antenna at different angles in the far-field. It is typically represented by a three-dimensional graph, or polar plots of the horizontal and vertical cross sections. The pattern of an ideal isotropic antenna, which radiates equally in all directions, would look like a sphere. Many nondirectional antennas, such as monopoles and dipoles, emit equal power in all horizontal directions, with the power dropping off at higher and lower angles; this is called an omnidirectional pattern and when plotted looks like a torus or donut.


title: Antenna (radio)

text: The radiation of many antennas shows a pattern of maxima or ""lobes"" at various angles, separated by ""nulls"", angles where the radiation falls to zero. This is because the radio waves emitted by different parts of the antenna typically interfere, causing maxima at angles where the radio waves arrive at distant points in phase, and zero radiation at other angles where the radio waves arrive out of phase. In a directional antenna designed to project radio waves in a particular direction, the lobe in that direction is designed larger than the others and is called the ""main lobe"". The other lobes usually represent unwanted radiation and are called ""sidelobes"". The axis through the main lobe is called the ""principal axis"" or ""boresight axis"".


title: Antenna (radio)

text: The polar diagrams (and therefore the efficiency and gain) of Yagi antennas are tighter if the antenna is tuned for a narrower frequency range, e.g. the grouped antenna compared to the wideband. Similarly, the polar plots of horizontally polarized yagis are tighter than for those vertically polarized.


title: Antenna (radio)

text: The space surrounding an antenna can be divided into three concentric regions: The reactive near-field (also called the inductive near-field), the radiating near-field (Fresnel region) and the far-field (Fraunhofer) regions. These regions are useful to identify the field structure in each, although the transitions between them are gradual, and there are no precise boundaries.


title: Antenna (radio)

text: The far-field region is far enough from the antenna to ignore its size and shape: It can be assumed that the electromagnetic wave is purely a radiating plane wave (electric and magnetic fields are in phase and perpendicular to each other and to the direction of propagation). This simplifies the mathematical analysis of the radiated field.


title: Antenna (radio)

text: "Efficiency" of a transmitting antenna is the ratio of power actually radiated (in all directions) to the power absorbed by the antenna terminals. The power supplied to the antenna terminals which is not radiated is converted into heat. This is usually through loss resistance in the antenna's conductors, or loss between the reflector and feed horn of a parabolic antenna.


title: Antenna (radio)

text: Antenna efficiency is separate from impedance matching, which may also reduce the amount of power radiated using a given transmitter. If an SWR meter reads 150 W of incident power and 50 W of reflected power, that means 100 W have actually been absorbed by the antenna (ignoring transmission line losses). How much of that power has actually been radiated cannot be directly determined through electrical measurements at (or before) the antenna terminals, but would require (for instance) careful measurement of field strength. The loss resistance and efficiency of an antenna can be calculated once the field strength is known, by comparing it to the power supplied to the antenna.


title: Antenna (radio)

text: The loss resistance will generally affect the feedpoint impedance, adding to its resistive component. That resistance will consist of the sum of the radiation resistance ' and the loss resistance '. If a current ' is delivered to the terminals of an antenna, then a power of '' will be radiated and a power of '' will be lost as heat. Therefore, the efficiency of an antenna is equal to . Only the total resistance ' + "" can be directly measured.


title: Antenna (radio)

text: According to reciprocity, the efficiency of an antenna used as a receiving antenna is identical to its efficiency as a transmitting antenna, described above. The power that an antenna will deliver to a receiver (with a proper impedance match) is reduced by the same amount. In some receiving applications, the very inefficient antennas may have little impact on performance. At low frequencies, for example, atmospheric or man-made noise can mask antenna inefficiency. For example, CCIR Rep. 258-3 indicates man-made noise in a residential setting at 40 MHz is about 28 dB above the thermal noise floor. Consequently, an antenna with a 20 dB loss (due to inefficiency) would have little impact on system noise performance. The loss within the antenna will affect the intended signal and the noise/interference identically, leading to no reduction in signal to noise ratio (SNR).


title: Antenna (radio)

text: Antennas which are not a significant fraction of a wavelength in size are inevitably inefficient due to their small radiation resistance. AM broadcast radios include a small loop antenna for reception which has an extremely poor efficiency. This has little effect on the receiver's performance, but simply requires greater amplification by the receiver's electronics. Contrast this tiny component to the massive and very tall towers used at AM broadcast stations for transmitting at the very same frequency, where every percentage point of reduced antenna efficiency entails a substantial cost.


title: Antenna (radio)

text: The definition of antenna gain or "power gain" already includes the effect of the antenna's efficiency. Therefore, if one is trying to radiate a signal toward a receiver using a transmitter of a given power, one need only compare the gain of various antennas rather than considering the efficiency as well. This is likewise true for a receiving antenna at very high (especially microwave) frequencies, where the point is to receive a signal which is strong compared to the receiver's noise temperature. However, in the case of a directional antenna used for receiving signals with the intention of "rejecting" interference from different directions, one is no longer concerned with the antenna efficiency, as discussed above. In this case, rather than quoting the antenna gain, one would be more concerned with the "directive gain", or simply "directivity" which does "not" include the effect of antenna (in)efficiency. The directive gain of an antenna can be computed from the published gain divided by the antenna's efficiency. In equation form, gain = directivity × efficiency.


title: Antenna (radio)

text: The orientation and physical structure of an antenna determine the "polarization" of the electric field of the radio wave transmitted by it. For instance, an antenna composed of a linear conductor (such as a dipole or whip antenna) oriented vertically will result in vertical polarization; if turned on its side the same antenna's polarization will be horizontal.


title: Antenna (radio)

text: Reflections generally affect polarization. Radio waves reflected off the ionosphere can change the wave's polarization. For line-of-sight communications or ground wave propagation, horizontally or vertically polarized transmissions generally remain in about the same polarization state at the receiving location. Using a vertically polarized antenna to receive a horizontally polarized wave (or visa-versa) results in relatively poor reception.


title: Antenna (radio)

text: An antenna's polarization can sometimes be inferred directly from its geometry. When the antenna's conductors "viewed from a reference location" appear along one line, then the antenna's polarization will be linear in that very direction. In the more general case, the antenna's polarization must be determined through analysis. For instance, a turnstile antenna mounted horizontally (as is usual), from a distant location on earth, appears as a horizontal line segment, so its radiation received there is horizontally polarized. But viewed at a downward angle from an airplane, the same antenna does "not" meet this requirement; in fact its radiation is elliptically polarized when viewed from that direction. In some antennas the state of polarization will change with the frequency of transmission. The polarization of a commercial antenna is an essential specification.


title: Antenna (radio)

text: In the most general case, polarization is elliptical, meaning that over each cycle the electric field vector traces out an ellipse. Two special cases are linear polarization (the ellipse collapses into a line) as discussed above, and circular polarization (in which the two axes of the ellipse are equal). In linear polarization the electric field of the radio wave oscillates along one direction. In circular polarization, the electric field of the radio wave rotates around the axis of propagation. Circular or elliptically polarized radio waves are designated as right-handed or left-handed using the "thumb in the direction of the propagation" rule. Note that for circular polarization, optical researchers use the opposite right hand rule from the one used by radio engineers.


title: Antenna (radio)

text: It is best for the receiving antenna to match the polarization of the transmitted wave for optimum reception. Otherwise there will be a loss of signal strength: when a linearly polarized antenna receives linearly polarized radiation at a relative angle of θ, then there will be a power loss of cosθ. A circularly polarized antenna can be used to equally well match vertical or horizontal linear polarizations, suffering a 3 dB signal reduction. However it will be blind to a circularly polarized signal of the opposite orientation.


title: Antenna (radio)

text: Maximum power transfer requires matching the impedance of an antenna system (as seen looking into the transmission line) to the complex conjugate of the impedance of the receiver or transmitter. In the case of a transmitter, however, the desired matching impedance might not exactly correspond to the dynamic output impedance of the transmitter as analyzed as a source impedance but rather the design value (typically 50 Ohms) required for efficient and safe operation of the transmitting circuitry. The intended impedance is normally resistive, but a transmitter (and some receivers) may have limited additional adjustments to cancel a certain amount of reactance, in order to "tweak" the match.


title: Antenna (radio)

text: When a transmission line is used in between the antenna and the transmitter (or receiver) one generally would like an antenna system whose impedance is resistive and nearly the same as the characteristic impedance of that transmission line, in addition to matching the impedance that the transmitter (or receiver) expects. The match is sought to minimize the amplitude of standing waves (measured via the standing wave ratio; SWR) that a mismatch raises on the line, and the increase in transmission line losses it entails.


title: Antenna (radio)

text: Antenna tuning, in the strict sense of modifying the antenna itself, generally refers only to cancellation of any reactance seen at the antenna terminals, leaving only a resistive impedance which might or might not be exactly the desired impedance (that of the transmission line).


title: Antenna (radio)

text: Although an antenna may be designed to have a purely resistive feedpoint impedance (such as a dipole 97% of a half wavelength long) this might not be exactly true at the frequency that it is eventually used at. In most cases, in principle the physical length of the antenna can be "trimmed" to obtain a pure resistance, although this is rarely convenient. On the other hand, the addition of a contrary inductance or capacitance can be used to cancel a residual capacitive or inductive reactance, respectively, and may be more convenient than lowering and trimming or extending the antenna, then hoisting it back.


title: Antenna (radio)

text: Antenna reactance may be removed using lumped elements, such as capacitors or inductors in the main path of current traversing the antenna, often near the feedpoint, or by incorporating capacitive or inductive structures into the conducting body of the antenna to cancel the feedpoint reactance – such as open-ended "spoke" radial wires, or looped parallel wires – hence genuinely tune the antenna to resonance. In addition to those reactance-neutralizing add-ons, antennas of any kind may include a balun at their feedpoint to transform the resistive part of the impedance to more nearly match the feedline's characteristic impedance.


title: Antenna (radio)

text: Antenna tuning in the loose sense, performed by an impedance matching device (somewhat inappropriately named an “"antenna tuner"”, or the older, more appropriate term "transmatch") goes beyond merely removing reactance and includes transforming the remaining resistance to match the feedline and radio.


title: Antenna (radio)

text: An additional problem is matching the remaining resistive impedance to the characteristic impedance of the transmission line: A general impedance matching network (an “antenna tuner” or ATU) will have at least two adjustable elements to correct both components of impedance. Any matching network will have both power losses and power restrictions when used for transmitting.


title: Antenna (radio)

text: Commercial antennas are generally designed to approximately match standard 50 Ohm coaxial cables, at standard frequencies; the design expectation is that a matching network will be merely used to ‘tweak’ any residual mismatch.


title: Antenna (radio)

text: In some cases matching is done in a more extreme manner, not simply to cancel a small amount of residual reactance, but to resonate an antenna whose resonance frequency is quite different from the intended frequency of operation.


title: Antenna (radio)

text: For instance, for practical reasons a “whip antenna” can be made significantly shorter than a quarter-wavelength and then resonated, using a so-called loading coil.


title: Antenna (radio)

text: The physically large inductor at the base of the antenna has an inductive reactance which is the opposite of the capacitative reactance that the short vertical antenna has at the desired operating frequency. The result is a pure resistance seen at feedpoint of the loading coil; although, without further measures, the resistance will be somewhat lower than would be desired to match commercial coax.


title: Antenna (radio)

text: Another extreme case of impedance matching occurs when using a small loop antenna (usually, but not always, for receiving) at a relatively low frequency, where it appears almost as a pure inductor. When such an inductor is resonated via a capacitor attached in parallel across its feedpoint, the capacitor not only cancels the reactance but also greatly magnifies the very small radiation resistance of a small loop to produce a better-matched feedpoint resistance.


title: Antenna (radio)

text: This is the type of antenna used in most AM broadcast receivers (other than car radios): The standard AM antenna is a loop of wire wound around a ferrite rod (a “"loopstick antenna"”). The loop is resonated by a capacitor which is varied simultaneously with tuning the receiver to a new frequency, in order to maintain antenna resonance over the AM broadcast band


title: Antenna (radio)

text: The radiation pattern and even the driving point impedance of an antenna can be influenced by the dielectric constant and especially conductivity of nearby objects. For a terrestrial antenna, the ground is usually one such object of importance. The antenna's height above the ground, as well as the electrical properties (permittivity and conductivity) of the ground, can then be important. Also, in the particular case of a monopole antenna, the ground (or an artificial ground plane) serves as the return connection for the antenna current thus having an additional effect, particularly on the impedance seen by the feed line.


title: Antenna (radio)

text: When an electromagnetic wave strikes a plane surface such as the ground, part of the wave is transmitted into the ground and part of it is reflected, according to the Fresnel coefficients. If the ground is a very good conductor then almost all of the wave is reflected (180° out of phase), whereas a ground modeled as a (lossy) dielectric can absorb a large amount of the wave's power. The power remaining in the reflected wave, and the phase shift upon reflection, strongly depend on the wave's angle of incidence and polarization. The dielectric constant and conductivity (or simply the complex dielectric constant) is dependent on the soil type and is a function of frequency.


title: Antenna (radio)

text: For very low frequencies to high frequencies (< 30 MHz), the ground behaves as a lossy dielectric, thus the ground is characterized both by a conductivity and permittivity (dielectric constant) which can be measured for a given soil (but is influenced by fluctuating moisture levels) or can be estimated from certain maps. At lower mediumwave frequencies the ground acts mainly as a good conductor, which AM broadcast (0.5–1.7 MHz) antennas depend on.


title: Antenna (radio)

text: At frequencies between 3–30 MHz, a large portion of the energy from a horizontally polarized antenna reflects off the ground, with almost total reflection at the grazing angles important for ground wave propagation. That reflected wave, with its phase reversed, can either cancel or reinforce the direct wave, depending on the antenna height in wavelengths and elevation angle (for a sky wave).


title: Antenna (radio)

text: On the other hand, vertically polarized radiation is not well reflected by the ground except at grazing incidence or over very highly conducting surfaces such as sea water. However the grazing angle reflection important for ground wave propagation, using vertical polarization, is "in phase" with the direct wave, providing a boost of up to 6 dB, as is detailed below.


title: Antenna (radio)

text: At VHF and above (> 30 MHz) the ground becomes a poorer reflector. However, for shortwave frequencies, especially below ~15 MHz, it remains a good reflector especially for horizontal polarization and grazing angles of incidence. That is important as these higher frequencies usually depend on horizontal line-of-sight propagation (except for satellite communications), the ground then behaving almost as a mirror.


title: Antenna (radio)

text: The net quality of a ground reflection depends on the topography of the surface. When the irregularities of the surface are much smaller than the wavelength, the dominant regime is that of specular reflection, and the receiver sees both the real antenna and an image of the antenna under the ground due to reflection. But if the ground has irregularities not small compared to the wavelength, reflections will not be coherent but shifted by random phases. With shorter wavelengths (higher frequencies), this is generally the case.


title: Antenna (radio)

text: Whenever both the receiving or transmitting antenna are placed at significant heights above the ground (relative to the wavelength), waves reflected specularly by the ground will travel a longer distance than direct waves, inducing a phase shift which can sometimes be significant. When a sky wave is launched by such an antenna, that phase shift is always significant unless the antenna is very close to the ground (compared to the wavelength).


title: Antenna (radio)

text: The phase of reflection of electromagnetic waves depends on the polarization of the incident wave. Given the larger refractive index of the ground (typically  ≈ 2) compared to air ( = 1), the phase of horizontally polarized radiation is reversed upon reflection (a phase shift of  radians, or 180°). On the other hand, the vertical component of the wave's electric field is reflected at grazing angles of incidence approximately "in phase". These phase shifts apply as well to a ground modeled as a good electrical conductor.


title: Antenna (radio)

text: This means that a receiving antenna "sees" an image of the emitting antenna but with 'reversed' currents (opposite in direction and phase) if the emitting antenna is horizontally oriented (and thus horizontally polarized). However, the received current will be in the same absolute direction and phase if the emitting antenna is vertically polarized.


title: Antenna (radio)

text: The actual antenna which is "transmitting" the original wave then also may "receive" a strong signal from its own image from the ground. This will induce an additional current in the antenna element, changing the current at the feedpoint for a given feedpoint voltage. Thus the antenna's impedance, given by the ratio of feedpoint voltage to current, is altered due to the antenna's proximity to the ground. This can be quite a significant effect when the antenna is within a wavelength or two of the ground. But as the antenna height is increased, the reduced power of the reflected wave (due to the inverse square law) allows the antenna to approach its asymptotic feedpoint impedance given by theory. At lower heights, the effect on the antenna's impedance is "very" sensitive to the exact distance from the ground, as this affects the phase of the reflected wave relative to the currents in the antenna. Changing the antenna's height by a quarter wavelength, then changes the phase of the reflection by 180°, with a completely different effect on the antenna's impedance.


title: Antenna (radio)

text: The ground reflection has an important effect on the net far field radiation pattern in the vertical plane, that is, as a function of elevation angle, which is thus different between a vertically and horizontally polarized antenna. Consider an antenna at a height above the ground, transmitting a wave considered at the elevation angle . For a vertically polarized transmission the magnitude of the electric field of the electromagnetic wave produced by the direct ray plus the reflected ray is:


title: Antenna (radio)

text: Thus the "power" received can be as high as 4 times that due to the direct wave alone (such as when  = 0), following the "square" of the cosine. The sign inversion for the reflection of horizontally polarized emission instead results in:


title: Antenna (radio)

text: For horizontal propagation between transmitting and receiving antennas situated near the ground reasonably far from each other, the distances traveled by the direct and reflected rays are nearly the same. There is almost no relative phase shift. If the emission is polarized vertically, the two fields (direct and reflected) add and there is maximum of received signal. If the signal is polarized horizontally, the two signals subtract and the received signal is largely cancelled. The vertical plane radiation patterns are shown in the image at right. With vertical polarization there is always a maximum for  = 0, horizontal propagation (left pattern). For horizontal polarization, there is cancellation at that angle. Note that the above formulae and these plots assume the ground as a perfect conductor. These plots of the radiation pattern correspond to a distance between the antenna and its image of 2.5  . As the antenna height is increased, the number of lobes increases as well.


title: Antenna (radio)

text: The difference in the above factors for the case of  = 0 is the reason that most broadcasting (transmissions intended for the public) uses vertical polarization. For receivers near the ground, horizontally polarized transmissions suffer cancellation. For best reception the receiving antennas for these signals are likewise vertically polarized. In some applications where the receiving antenna must work in any position, as in mobile phones, the base station antennas use mixed polarization, such as linear polarization at an angle (with both vertical and horizontal components) or circular polarization.


title: Antenna (radio)

text: On the other hand, analog television transmissions are usually horizontally polarized, because in urban areas buildings can reflect the electromagnetic waves and create ghost images due to multipath propagation. Using horizontal polarization, ghosting is reduced because the amount of reflection in the horizontal polarization off the side of a building is generally less than in the vertical direction. Vertically polarized analog television have been used in some rural areas. In digital terrestrial television such reflections are less problematic, due to robustness of binary transmissions and error correction.


title: Antenna (radio)

text: The flow of current in wire antennas is identical to the solution of counter-propagating waves in a single conductor transmission line, which can be solved using the telegrapher's equations.


title: Antenna (radio)

text: Solutions of currents along antenna elements are more conveniently and accurately obtained by numerical methods, so transmission-line techniques have largely been abandoned for precision modelling, but they continue to be a widely used source of useful, simple approximations that describe well the impedance profiles of antennas.


title: Antenna (radio)

text: Unlike transmission lines, currents in antennas contribute power to the radiated part electromagnetic field, which can be modeled using radiation resistance.


title: Antenna (radio)

text: The end of an antenna element corresponds to an unterminated (open) end of a single-conductor transmission line, resulting in a reflected wave identical to the incident wave, with its voltage "in" phase with the incident wave


title: Antenna (radio)

text: and its current in the "opposite" phase (thus net zero current, where there is, after all, no further conductor). The combination of the incident and reflected wave, just as in a transmission line, forms a standing wave with a current node at the conductor's end, and a voltage node one-quarter wavelength from the end (if the element is at least that long).


title: Antenna (radio)

text: In a "resonant antenna", the feedpoint of the antenna is at one of those voltage nodes. Due to discrepancies from the simplified version of the transmission line model, the voltage one quarter wavelength from the current node is not exactly zero, but it is near a minimum, and small compared to the much large voltage at the conductor's end. Hence, a feed point matching the antenna at that spot requires a relatively small voltage but large current (the currents from the two waves add in-phase there), thus a relatively low feedpoint impedance.


title: Antenna (radio)

text: Feeding the antenna at other points involves a large voltage, thus a large impedance, and usually one that is primarily reactive (low power factor), which is a terrible impedance match to available transmission lines. Therefore it is usually desired for an antenna to operate as a resonant element with each conductor having a length of one quarter wavelength (or any other odd multiples of a quarter wavelength).


title: Antenna (radio)

text: For instance, a half-wave dipole has two such elements (one connected to each conductor of a balanced transmission line) about one quarter wavelength long. Depending on the conductors' diameters, a small deviation from this length is adopted in order to reach the point where the antenna current and the (small) feedpoint voltage are exactly in phase. Then the antenna presents a purely resistive impedance, and ideally one close to the characteristic impedance of an available transmission line.


title: Antenna (radio)

text: Despite these useful properties, resonant antennas have the disadvantage that they achieve resonance (purely resistive feedpoint impedance) only at a fundamental frequency, and perhaps some of its harmonics, and the feedpoint resistance is larger at higher-order resonances. Therefore resonant antennas can only achieve their good performance within a limited bandwidth, depending on the at the resonance.


title: Antenna (radio)

text: The electric and magnetic fields emanating from a driven antenna element will generally affect the voltages and currents in nearby antennas, antenna elements, or other conductors. This is particularly true when the affected conductor is a resonant element (multiple of half-wavelengths in length) at about the same frequency, as is the case where the conductors are all part of the same active or passive antenna array.


title: Antenna (radio)

text: Because the affected conductors are in the near-field, one can "not" just treat two antennas as transmitting and receiving a signal according to the Friis transmission formula for instance, but must calculate the "mutual impedance" matrix which takes into account both voltages and currents (interactions through both the electric and magnetic fields). Thus using the mutual impedances calculated for a specific geometry, one can solve for the radiation pattern of a Yagi–Uda antenna or the currents and voltages for each element of a phased array. Such an analysis can also describe in detail reflection of radio waves by a ground plane or by a corner reflector and their effect on the impedance (and radiation pattern) of an antenna in its vicinity.


title: Antenna (radio)

text: Often such near-field interactions are undesired and pernicious. Currents in random metal objects near a transmitting antenna will often be in poor conductors, causing loss of RF power in addition to unpredictably altering the characteristics of the antenna. By careful design, it is possible to reduce the electrical interaction between nearby conductors. For instance, the 90 degree angle in between the two dipoles composing the turnstile antenna insures no interaction between these, allowing these to be driven independently (but actually with the same signal in quadrature phases in the turnstile antenna design).


title: Antenna (radio)

text: Antennas can be classified by operating principles or by their application. Different authorities placed antennas in narrower or broader categories. Generally these include


title: Antenna (radio)

text: These antenna types and others are summarized in greater detail in the overview article, Antenna types, as well as in each of the linked articles in the list above, and in even more detail in articles which those link to.


title: Elephant (2003 film)

text: Elephant is a 2003 American psychological drama film written, directed, and edited by Gus Van Sant. It takes place in the fictional Watt High School, in the suburbs of Portland, Oregon, and chronicles the events surrounding a school shooting, based in part on the 1999 Columbine High School massacre. The film begins a short time before the shooting occurs, following the lives of several characters both in and out of school, who are unaware of what is about to unfold. The film stars mostly new or non-professional actors, including John Robinson, Alex Frost, and Eric Deulen.


title: Elephant (2003 film)

text: "Elephant" is the second film in Van Sant's "Death Trilogy"—the first is "Gerry" (2002) and the third "Last Days" (2005)—all three of which are based on actual events.


title: Elephant (2003 film)

text: Although "Elephant" was controversial for its subject matter and allegations of influence on the Red Lake shootings, it was generally praised by critics and received the Palme d'Or at the 2003 Cannes Film Festival, in which Patrice Chéreau was the head of the jury.


title: Elephant (2003 film)

text: At the start of the film, John McFarland is being driven to school by his father, who is driving erratically down the road. Noticing the damage done to the car, John realizes that his father is drunk and makes him move to the passenger seat so he can drive. When John arrives at school late, he is reprimanded by the principal, Mr. Luce.


title: Elephant (2003 film)

text: The majority of the film is spent following several high school students going about their daily lives just before a school shooting. In addition to John, who struggles with controlling his alcoholic father, photography student Elias builds a portfolio of other students. Outcast Michelle struggles with her body issues and assists in the library. Bulimics Nicole, Brittany, and Jordan gripe about their parents and squabble while popular athlete and lifeguard Nathan meets with his girlfriend, Carrie. Acadia, a close friend of John's, attends a Gay-Straight Alliance meeting.


title: Elephant (2003 film)

text: Unknown to anyone, two other students, Alex and Eric, are preparing to carry out a bomb/shooting attack on their school. Flashbacks throughout the film show them preparing for the massacre by ordering weapons online and formulating an attack plan. The two have a brief sexual encounter in the shower after they both admit that they've never kissed anyone before. Their motives for the shooting appear vague; the film provides evidence suggesting bullying, neglect, violent video games, and Nazism.


title: Elephant (2003 film)

text: On the day of the shooting, the pair make their way to school in Alex's car. Alex is armed with a Carbon-15 and a shotgun while Eric has a TEC-9. As they enter the school, they encounter John, and Alex tells him to leave. Realizing what is about to happen, John tries to warn students and teachers outside not to go into the school, but few people listen. He then notices his dad is missing after they arrived earlier and goes looking for him.


title: Elephant (2003 film)

text: Alex and Eric plant propane bombs in the cafeteria, hoping to blow it up and shoot people as they try to escape the fire. When the bombs fail, they decide to start shooting indiscriminately. The pair head into the library, where Elias photographs them right before they open fire on students. Michelle is killed, while Elias' fate is left unclear. Other students quickly realize that the gunfire is real and begin to panic, and teachers begin evacuating students.


title: Elephant (2003 film)

text: Alex and Eric split up to opposing ends of the school to continue their shooting. Alex enters the girls' bathroom where he surprises Jordan, Nicole, and Brittany, presumably shooting all three. A student attending the Gay-Straight Alliance meeting enters the hallway investigating the gunfire and is shot dead. The alliance members evacuate through a window save for Acadia, who freezes at the sight of her dead classmate. Benny, an African-American student athlete, finds her and helps her out the window before deciding to find and confront the shooters.


title: Elephant (2003 film)

text: Outside the school, John finds his now sobered-up father, who tries to comfort his son as the shooting continues. While helping students escape, Mr. Luce is cornered and threatened by Eric, prompting Mr. Luce to try and reason with him. Benny walks up behind Eric, but Eric abruptly turns around and shoots Benny dead. Eric tells Mr. Luce not to treat kids like him and Alex poorly. He then lets Mr. Luce go, only to gun him down seconds later.


title: Elephant (2003 film)

text: Alex enters the cafeteria, which is strewn with overturned chairs, backpacks, several dead bodies, and numerous abandoned half-eaten lunches, and sits down. Alex picks up a cup from an abandoned lunch and casually drinks from it. Eric meets up with him, and they have a brief conversation about who they've shot, which ends when Alex shoots Eric mid-sentence. Alex leaves the cafeteria, showing no emotion over killing Eric, and discovers Carrie and Nathan hiding in a freezer. He tauntingly recites "Eeny, meeny, miny, moe" to them to decide whom he should kill first. The film then cuts to credits leaving the ending ambiguous.


title: Elephant (2003 film)

text: The film began as a documentary that Van Sant had intended to make about the Columbine High School massacre; eventually, the idea of a factual account was dropped.


title: Elephant (2003 film)

text: "Elephant" was filmed in Van Sant's hometown, Portland, Oregon, in late 2002, on the former campus of Whitaker Middle School (previously Adams High School). Whitaker was closed by the Portland Public Schools in 2001 due to structural problems and safety concerns with the school building. The Whitaker/Adams building, completed in 1969, was torn down in 2007.


title: Elephant (2003 film)

text: There was no initial script before the filming started. The script was "written" to its final form during shooting, with cast members improvising freely and collaborating in the direction of scenes. It was shot over 20 days.


title: Elephant (2003 film)

text: The title "Elephant" is a tribute to the 1989 BBC short film of the same name, directed by Alan Clarke. Van Sant originally believed Clarke's title referred to the parable of the blind men and an elephant, in which several blind men try to describe an elephant, and each draws different conclusions based on which body part he touched, and Van Sant's film uses that interpretation, as the same general timeline is shown multiple times from multiple viewpoints. Later, Van Sant discovered Clarke's film referred to the phrase "elephant in the room" (the collective denial of some obvious problem).


title: Elephant (2003 film)

text: Also, Gus Van Sant named Chantal Akerman's film "Jeanne Dielman, 23 quai du Commerce, 1080 Bruxelles" (1975) an inspiration.


title: Elephant (2003 film)

text: Clarke's film "Elephant" reflects on sectarian violence in Northern Ireland. Van Sant's minimalist style and use of tracking shots mirrors Clarke's film.


title: Elephant (2003 film)

text: A drawing of an elephant as well as an image of an elephant on a bed throw can be seen in Alex's room while he plays the piano.


title: Elephant (2003 film)

text: The film competed at the Cannes Film Festival in May 2003. Van Sant claimed audiences in attendance at Cannes argued over its quality, leading to altercations.


title: Elephant (2003 film)

text: "Elephant" received mainly positive reviews from critics and has a score of 73% on Rotten Tomatoes based on 160 reviews with an average rating of 7.10/10. The critical consensus states "The movie's spare and unconventional style will divide viewers." The film also has a score of 70 out of 100 on Metacritic based on 37 critics indicating "generally favourable reviews".


title: Elephant (2003 film)

text: Roger Ebert praised the film and gave it 4 out of 4 stars writing "Gus Van Sant's "Elephant" is a violent movie in the sense that many innocent people are shot dead. But it isn't violent in the way it presents those deaths. There is no pumped-up style, no lingering, no release, no climax. Just implacable, poker-faced, flat, uninflected death. Truffaut said it was hard to make an anti-war film because war was exciting even if you were against it. Van Sant has made an anti-violence film by draining violence of energy, purpose, glamor, reward and social context. It just happens. I doubt that "Elephant" will ever inspire anyone to copy what they see on the screen. Much more than the insipid message movies shown in social studies classes, it might inspire useful discussion and soul-searching among high school students."


title: Elephant (2003 film)

text: The Red Lake shootings that occurred in 2005 were briefly blamed on the film, as it was viewed by gunman Jeff Weise 17 days prior to the event. A friend of Weise said that he brought the film over to a friend's house and skipped ahead to parts that showed two students planning and carrying out a school massacre. Although they talked about the film afterwards, Weise said and did nothing to make anyone suspect what he was planning.


title: Maharaja

text: Mahārāja (; also spelled Maharajah, Maharaj) is a Sanskrit title for a "great ruler", "great king" or "high king".


title: Maharaja

text: A few ruled states informally called empires, including ruler raja Sri Gupta, founder of the ancient Indian Gupta Empire, and Chandragupta Maurya. 'Title inflation' soon led to most being rather mediocre or even petty in real power, which led to compound titles (among other efforts) being used in an attempt to distinguish some among their ranks.


title: Maharaja

text: The female equivalent, Maharani (or Maharanee, Mahārājñī, Maharajin), denotes either the wife of a Maharaja (or Maharana etc.) or also, in states where it was customary, a woman ruling without a husband. The widow of a Maharaja is known as a Rajmata, "queen mother". Maharajakumar generally denotes a son of a Maharaja, but more specific titulatures are often used at each court, including Yuvaraja for the heir (the crown prince). The form "Maharaj" (without "-a") indicates a separation of noble and religious offices, although since in Hindi the suffix "-a" is silent, the two titles are near homophones.


title: Maharaja

text: The word "Maharaja" originates in Sanskrit and is a compound karmadhāraya term from "mahānt-" "great" and "rājan" "ruler, king"). It has the Latin cognates "magnum" "great" and "rex" "king". Due to Sanskrit's major influence on the vocabulary of most languages in Greater India and Southeast Asia, the term Maharaja is common to many modern Indo-Aryan and Dravidian languages. The Sanskrit title Maharaja was originally used only for rulers who ruled a considerably large region with minor tributary rulers under them. Since medieval times, the title was used by (Hindu) monarchs of lesser states claiming descent from ancient Maharajas.


title: Maharaja

text: On the eve of independence in 1947, British India contained more than 600 princely states, each with its own native ruler, often styled Raja or Rana or Thakur (if the ruler were Hindu) or Nawab (if he were Muslim), with a host of less current titles as well.


title: Maharaja

text: The British directly ruled two-thirds of the Indian subcontinent; the rest was under indirect rule by the above-mentioned princes under the considerable influence of British representatives, such as Residents, at their courts.


title: Maharaja

text: The word Maharaja may be understood simply to mean "ruler" or "king", in spite of its literal translation as "great king". This was because only a handful of the states were truly powerful and wealthy enough for their rulers to be considered 'great' monarchs; the remaining were minor princely states, sometimes little more than towns or groups of villages. The word, however, can also mean emperor in contemporary Indian usage.


title: Maharaja

text: The title of Maharaja was not as common before the gradual British colonisation of India, upon and after which many Rajas and otherwise styled Hindu rulers were elevated to Maharajas, regardless that scores of these new Maharajas ruled small states, sometimes for some reason unrelated to the eminence of the state, for example, support to the British in Afghanistan, World War I or World War II. The Maharaja of Punjab in the 19th century was Maharaja Ranjit Singh. He earned this title by keeping the Britishers beyond the Sutlej and even crushed the Afghan Empire. Maharajas in the twentieth century were the Maharaja of Cochin and Maharaja Jagatjit Singh of Kapurthala. Apart from princely states, rulers of some large and extended zamindaris were also awarded the title of Maharaja. The rulers of Jeypore, Darbhanga, Vizianagaram, Parlakhemundi were a few zamindars who were titled Maharaja for their cordiality and contribution to the British Raj.


title: Maharaja

text: In the Mughal Empire it was quite common to award to various princes (hereditary or not) a series of lofty titles as a matter of protocolary rank. The British would, as paramount power do the same.


title: Maharaja

text: Many of these (see also above) elaborate explicitly on the title Maharaja, in the following descending order:


title: Maharaja

text: Certain Hindu dynasties even came to use a unique style, including a term which as such is not of princely rank, e.g. Maharaja Gaikwar of Baroda, Maharaja Scindia of Gwalior, Maharaja Holkar of Indore, three of the very highest ranking ruling Maratha houses.


title: Maharaja

text: At the absence of the king (maharaja), minor heir, less experienced Queen (Maharani); the mother of the king takes charge of the kingdom and acts as an temporary monarch/regent. Until the heir comes to the age or the Queen is ready, the Rajmata (Queen mother) administers the kingdom. She is empowered to issue royal decree (Rajyaadesh/rajya shasan) and she will be the head of the military. Famous examples include Rajmata Shetu Lakshmi Bayi of Travincore dynasty, Gowri lakshmi bayi, Maharaji (later Rajmata) Rudrama devi of Kakatiya dynasty. The Rajmata can overrule the advise of ministerial council, abolish or impose tax, appoint or dismiss people from a post and has unlimited powers at the absence of the king.


title: Maharaja

text: When the king is present, the Rajmata being the mother of the king, are given with certain powers to roles. They often share the burden of the ruling king/queen. Few of the powers they are granted (not limited) with are "powers to summon the king, appoint certain people, issue police orders, religious duties, issue death warrant and other minor powers". Famous Rajmata who functioned with the king is Rajmata Jijabai of vast Maratha empire, accompanying the chakravarti (emperor).


title: Maharaja

text: Chakravarti is a Sanskrit term for "emperor". The meaning of chakravatri is "he, whose wheels of chariot is moving" which symbolizes that the leader who is a war hero, who commands over vast land and sea, the one who rules the people with dedication. In the Mahabharata, the Chakravarti Bharat is known to have ruled the entire sub-continent of India brought golden age to his kingdom. He is called as chakravarti.


title: Maharaja

text: Chakravartini is the female equivalent to the Chakravarti, and hence, is the "Empress". She can either be the wife of the chakravarti or she herself is the ruling monarch. Chakravartini is more famously known as Samrajyani or Samrajyadekshini if she is the ruling monarch.


title: Maharaja

text: Yuvaraja means the crown prince of the kingdom. He is granted with certain powers and responsibilities so that he can be prepared to take over as the Maharaja.


title: Maharaja

text: Yuvarani is the royal title given to the wife of a crown prince. A yuvarani is trained in religious, administrative and judiciary sections but is also trained to command armies in the absence of the King.


title: Maharaja

text: Rajakumara is a prince who is not going to be the next Maharaja. He is created as royal blood and based on the confort of the King/queen, he is conferred with certain duties.


title: Maharaja

text: Like "Raja" and various other titles, "Maharaja" was repeatedly awarded to notables without a princely state, such as zamindars.


title: Maharaja

text: "Maharaj Kumar" (or Maharajkumar) means son of a Maharaja or Heir-Apparent; the female equivalent is "Maharaj Kumari (Maharajkumari"): daughter of a Maharaja.


title: Maharaja

text: The Gurkha Kings of Nepal (now a republic) used the title of Mahārājādhirāja which was "King among Great Kings", a title of honour, a degree higher than Mahārājā.


title: Maharaja

text: When the Indonesian archipelago was still predominantly Hindu-Buddhist (circa 3rd century CE until the 15th century CE), all of the Indianized kingdoms which ruled different areas of the archipelago was ruled by a "Maharaja" or simply referred by the locals as "Raja", such as the first and oldest Hindu kingdom of Indonesia the Kutai Martadipura in eastern Borneo, the Tarumanegara, the Srivijaya, the Majapahit and numerous other kingdoms. Traditional titles remain in use for other members of royalty, such as Pangeran Ratu for the heir and other local-Malay titles such as "Paduka Sri". The title "Maharaja" has been used to refer to kings of ancient Indianized kingdoms, such as Maharaja Mulavarman king of Kutai Martadipura and Maharaja Purnawarman king of Tarumanegara.


title: Maharaja

text: Maharaja was also part of the titles of the nobility in the Sumatran sultanate of Aceh. In the past, the title of Maharaja is given to a leader of the unreigning noble family and the Prime Minister Maharaja Mangkubumi. The last Prime Minister of Aceh who was installed to be the Maharaja Mangkubumi, Habib Abdurrahman el Zahir, who also acted as the foreign affairs minister of Aceh but was deposed and exiled to Jeddah by the colonial Dutch East Indies authorities in October 1878.


title: Maharaja

text: In northern Borneo, the title Maharajah of Sabah and Rajah of Gaya and Sandakan was used from 29 December 1877 to 26 August 1881 by Baron von Overbeck (compare White Rajah).


title: Maharaja

text: The Englishman Capt. James Brooke was declared as Rajah Brooke by the Sultan of Brunei for his role in pacifying the Sarawak revolt against the Sultan during the Raffles' stint. The word "Rajah" derived from the word Maharaja. In 1842, the Sultan of Brunei ceded Sarawak to Rajah Brooke who founded the Kingdom of Sarawak and a line of dynastic monarchs known as the White Rajahs.


title: Maharaja

text: In contemporary Malay usage, the title "Maharaja" refers to an emperor, e.g. ""Maharaja Jepun"" ("Emperor of Japan").


title: Maharaja

text: In Seri Malayas of the Srivijaya, under the Srivijaya satellite empire of the Majapahit Empire dominated over the whole Malayas far-reaching the present Philippine Archipelago, Malaysia, Brunei, Indonesia under the Srivijaya Empire of the Majapahit King Maharaja Pamariwasa. The latter's daughter Es-kander was married to an Arab (Zein Ul-Abidin), the third Makdum who promulgated Koranic studies (Madrassahs) and was a Srivijaya ruler in Seri who were a Srivijaya Monarchy. In the 12th century with the fall of the empire, the Seri King being a Muslim established the Sultanate of Brunei in 1363 with the throne name Sultan Mohamad Shah. In 1426, he established the sultanate of sulu as his death was recorded in 1431 Mt. Makatangis Sulu grave and 1432 Brunei grave. Both Sulu and Brunei claim the honor of his grave, while his brother, a Johore (Singapore) Prince Makdum Karim (Sharif Kabungsuwan of Malabang Lanao) the second Makdum after the first one Makdum Tuan Masha'ik. Karim ul-makdum re=enforced Islam, a Srivijaya Johore ruler, later established the Sultanate of Maguindanao-Ranao (Mindanao) after taking the political authority of his father-in-law Tomaoi Aliwya of the Maguiindanao family dynasty. He adapted the title as sultan Aliwya (Sharif Kabungsuwan), the first Maguindanao Sultan. The second and third Makdum's father was Sultan Betatar of Taif Arabia who was the 9th progeny of Hasan, the grandson of prophet Sayyidina Muhammad.


title: Maharaja

text: Most famous was Bendahara Seri Maharaja Tun Mutahir of Malacca (executed 1509) and Datuk Maharaja Lela Pandak Lam of Perak (executed 1876).


title: Maharaja

text: The palace marshal of the Yang di-Pertuan Agong (head of state) of modern Malaysia is called "Datuk Maharaja Lela Penghulu Istana Negara".


title: Maharaja

text: Eventually, Maharajah Adinda was also used to refer to a particular lineage within the royal families.


title: Natali Germanotta

text: Natali Veronica Germanotta (born March 10, 1992) is an American fashion designer and stylist. She founded the fashion label Topo Studio. She is the younger sister of singer Lady Gaga.


title: Natali Germanotta

text: Germanotta was born on March 10, 1992, in New York City to business executives Joseph Germanotta and Cynthia Bissett and grew up on the Upper West Side of Manhattan. She was raised in the Catholic faith and is of Italian descent. Germanotta is the younger sister of singer and actress Lady Gaga. She attended the Convent of the Sacred Heart, a private all-girls Roman Catholic school located on the Upper East Side. After graduating, she studied fashion at Parsons School of Design, a constituent college of The New School.


title: Natali Germanotta

text: In February 2016, Germanotta and her sister, Lady Gaga partnered with Mattel's "Monster High", in conjunction with the Born This Way Foundation as part of the #KindMonsters campaign, to create a doll for the franchise.


title: Natali Germanotta

text: Germanotta works as a fashion designer, and founded the fashion label Topo Studio. In 2011, she created costumes for an off-Broadway show, "Simon Says". She has designed for and styled Lady Gaga, including for a spread in "Harper's Bazaar" in 2014. She worked as a stylist on set for the film "A Star Is Born" (2018) and also designed outfits for Gaga's Jazz & Piano residency (2019–2022), as well as concert tours the Cheek to Cheek Tour (2014–2015) and The Chromatica Ball (2022). Talking about working together, she said: "I like to close my eyes after combing through reference images, and imagine my sister singing. [...] [Collaborating] never feels like work. It feels really unrestrained and free, from start to finish."


title: Turing Award

text: The ACM A. M. Turing Award is an annual prize given by the Association for Computing Machinery (ACM) for contributions of lasting and major technical importance to computer science. It is generally recognized as the highest distinction in computer science and is colloquially known as or often referred to as the "Nobel Prize of Computing".


title: Turing Award

text: The award is named after Alan Turing, who was a British mathematician and reader in mathematics at the University of Manchester. Turing is often credited as being the key founder of theoretical computer science and artificial intelligence. From 2007 to 2013, the award was accompanied by an additional prize of US$250,000, with financial support provided by Intel and Google. Since 2014, the award has been accompanied by a prize of US$1 million, with financial support provided by Google.


title: Turing Award

text: The first recipient, in 1966, was Alan Perlis, of Carnegie Mellon University. The first female recipient was Frances E. Allen of IBM in 2006.


title: Audi Quattro

text: The Audi Quattro is a road and rally car, produced by the German automobile manufacturer Audi, part of the Volkswagen Group. It was first shown at the 1980 Geneva Motor Show on 3 March. Production continued through 1991.


title: Audi Quattro

text: The word "quattro" is derived from the Italian word for "four" to represent the fact that the vehicle delivers power to all four wheels. The name has also been used by Audi to refer to the quattro four-wheel-drive system, or any four-wheel-drive version of an Audi model. The original Quattro model is also commonly referred to as the Ur-Quattro - the "Ur-" (German for "primordial", "original", or "first of its kind") is an augmentative prefix. The idea of such a car came from the Audi engineer Jörg Bensinger.


title: Audi Quattro

text: The Audi Quattro was the first rally car to take advantage of the then-recently changed rules that allowed the use of four-wheel drive in competition racing. It won consecutive competitions for the next two years. To commemorate the success of the original vehicle, all subsequent Audi production automobiles with this four-wheel-drive system were badged with the trademark quattro with a lower case "q" letter.


title: Audi Quattro

text: The Audi Quattro shared many parts and platform with the Coupé version of the Audi 80 (B2). The quattro was internally designated "Typ 85", a production code it shared with the quattro versions of the Audi Coupé. Its characteristic flared wheelarches were styled by Martin Smith. The Audi Quattro also had independent front and rear suspension.


title: Audi Quattro

text: The idea for a high-performance four-wheel-drive car was proposed in 1977 by Audi's chassis engineer, Jörg Bensinger, after he found that the Volkswagen Iltis military vehicle could outperform other vehicles when tested in the snow. An Audi 80 variant was developed in co-operation with Walter Treser, Director of Pre-Development.


title: Audi Quattro

text: Audi introduced the original Quattro to European customers in late 1980, featuring Audi's quattro permanent four-wheel drive system, and the first to mate the front-engine, four-wheel-drive layout with a turbocharged engine.


title: Audi Quattro

text: The original engine was the , longitudinally-mounted inline-5-cylinder 10 valve SOHC, with a turbocharger and intercooler. It generated and torque of at 3,500 rpm, propelling the Quattro from 0 to in 7.1 seconds, and on to a top speed of over .


title: Audi Quattro

text: The displacement of the engine was dropped slightly from 2144 cc to 2133 cc with a bore x stroke of for the Rally car so that Audi could satisfy the 3-litre rallying class with a 1.4 times multiplication factor. Valvetrain was DOHC 4 valves per cylinder (20 valves in total) with an oil cooled KKK K27 turbocharger at and Air-to-Air - Längerer & Reich intercooler fed by Bosch LH-Jetronic fuel injection, generating at 6,700 rpm and of torque at 3,700 rpm.


title: Audi Quattro

text: The engine was eventually modified to a inline-5 with 10 valves, still generating , but with peak torque lower in the rev-range. In 1989, it was then changed to a inline-five 20-valve DOHC setup generating , now with a top speed of .


title: Audi Quattro

text: The Quattro was partially hand-built on a dedicated line. Production totaled 11,452 units from 1980 to 1991, and through this 11 year production there were no major changes in the visual design of the car. For the 1983 model year, the dashboard did away with an analogue instrument cluster now fitted with a green digital liquid crystal display (LCD) electronic instrument cluster. This was later changed in 1988 to an orange LCD electronic instrument cluster. The interior was redesigned in 1984, and featured a new dashboard layout, new steering wheel design, and new centre console design, the switches around the instrument panel were also redesigned. In 1985, the dashboard changed slightly with harder foam and it lost a diagonal stripe, the switches were varied slightly and the diff lock pull knob gave way to a two-position turn knob with volt and oil temp digital readouts.


title: Audi Quattro

text: Exterior styling received little modification during the Quattro's production run. Originally, the car had a flat front grille featuring four separate headlamp lenses, one for each of the low and high beam units. This was altered for the 1983 model year with combined units featuring a single lens housing twin reflectors. This was changed again, for the 1985 model year, in what has become known as the 'facelift model' and included such alterations as a new sloping front grille, headlights, and trim and badging changes. The 20V RR Quattro also featured a new three-spoke steering wheel design, leather trim for door arm rests, gloveboxes, centre console and door pockets. There was also a full length leather-wrapped centre console running all the way to the rear seats and 'quattro' script on the interior with partial leather seats. The floor on the driver's side had a bulge due to dual catalytic exhaust setup. The different models may be distinguished by the emblems on their boot lids: the WR had a vinyl 'quattro' decal or a brushed aluminium effect plastic emblem, the MB had chrome plated 'Audi', 'Audi rings' and 'quattro' emblems, whilst the RR had only chrome plated 'Audi rings'.


title: Audi Quattro

text: The rear suspension was altered early on with geometry changes and removal of the rear anti-roll bar to reduce a tendency for lift-off oversteer. For the 1984 facelift, the wheel size went from 6x15-inch with 205/60-15 tyres to 8x15-inch wheels with 215/50-15 Pirelli Cinturato P5 tyres. At the same time the suspension was lowered by 20 mm with slightly stiffer springs for improved handling. For 1987, the Torsen centre differential was used for the first time, replacing the manual centre differential lock.


title: Audi Quattro

text: The last original Audi Quattro was produced on 17 May 1991, more than two years after the first models of the new Audi Coupé (8B) range (based on the 1986 Audi 80) had been introduced.


title: Audi Quattro

text: Sales of the Quattro in North America began in the 1983 model year. They entered the all-wheel-drive market established by the AMC Eagle, the first full-time automatic all-wheel-drive line of passenger cars to reach mass production. The small Subaru Leone station wagon offered an optional part-time 4-wheel drive system in the US market starting in 1975.


title: Audi Quattro

text: The North American Quattro was manufactured concurrently and were of the same design as their European 1982 model year counterparts (they did not include the minor cosmetic changes of the 1983 European model) and continued through 1986. Total sales in the U.S. totalled 664 units. The Canadian market cars were identical to the U.S. version with exception of the speedometer, which was metric. Official sales figures for Canada were 99 units, which included 61 sold in 1983, 17 sold in 1984, 18 sold in 1985, and 3 sold in 1986.


title: Audi Quattro

text: The U.S./Canadian cars were equipped with larger impact bumpers with built-in shock absorbers, like the rest of the 4000/Coupé models. They did not have anti-lock braking system (ABS), but included air conditioning and leather upholstery. Most of the 1984 and 1985 Canadian models came without sunroofs. The remainder of the electric, suspension, and cosmetic updates took place at the same time as the European cars.


title: Audi Quattro

text: The initial 2.1 L (2,144 cc, engine code "WX") engine for U.S./Canadian models included minor component and engine control unit (ECU) changes, lowered turbocharger boost pressure, different camshaft, as well as emission controls that consisted of a catalytic converter and lambda stoichiometric fuel control that lowered power output to . Other mechanical specifications were identical to the European market vehicles. The WX engine was also utilized in Swiss and Japanese market cars. Audi built 200 special edition cars in 1988 with the WX engine and analogue instrument cluster, with everything else identical to the MB model of that year.


title: Audi Quattro

text: In May 1981, "Autocar" magazine road tested a left hand drive Quattro (registration number WBD 335W), one of the first magazines to do so since it was introduced. Beginning with a photograph in the magazine of a Quattro cornering hard on Pendine beach in South-west Wales, Autocar's Road Test Editor raved about the Quattro's "thrilling performance" being impressed with its traction and acceleration particularly on wet, greasy and slippery surfaces, noting that only the Porsche 911 could match its traction and acceleration in slippery conditions. After extensive driving across the mountain roads of Wales, the Road Test editor mentioned that while the 60/40 front/rear weight distribution can make the Quattro "tricky in extremis" under very hard cornering, the editor wrote that "When Driven with respect, once you have learned its ways, the Quattro is nevertheless magnificent, particularly through a wet and deserted roundabout or series of open bends." The road test editor praised the interior's "comfortable refinement" and judged that its 1981 £14,500 price tag "is very good value for money considering its performance and the fact that its BMW, Porsche and Jaguar rivals cost £5000 more." (In summer 1981 both a Jaguar XJS V12 and BMW 6 Series Coupe on sale in the UK cost almost £20,000). Adding the caveat that in 1981 (and until summer 1983) the Quattro was only available in left hand drive in the UK, the Autocar Road Test concluded that the Quattro "is a vastly satisfying and enjoyable car to drive."


title: Audi Quattro

text: The Audi quattro Spyder was a mid-engine coupé equipped with a 2.8-litre V6 engine taken from the Audi 100. The engine was rated at and of torque. The car was a rolling test bed for a future mid-engine sports car and featured a 5-speed manual gearbox, a modified version for the quattro four-wheel-drive system, aluminium body panels with a tubular steel space frame, kerb weight and a suspension system with trapezoidal links. All of the unique features depicted in the concept car would find their way in future Audi production vehicles.


title: Audi Quattro

text: The car was production-ready and garnered a lot of acclaim from both the motoring press and prospective buyers but due to the economic downturn of the 1990s, Audi decided not to press ahead with the project as the demand would not outweigh the development costs for the model.


title: Audi Quattro

text: At the Paris Motor Show in 2010, Audi presented the quattro concept on the occasion of the 30th anniversary of the original Audi Quattro and the Audi quattro four-wheel-drive system. Based on the RS5, it features a modified 2.5 L five-cylinder TFSI engine shared with the TT and a 6-speed manual transmission from the S4. The engine was claimed to generate a maximum power output of and of torque. The revolutionary design features depicted on the concept car would eventually make their way on future Audi models.


title: Audi Quattro

text: The concept utilised aluminium and carbon fibre construction which helped to achieve a total dry weight of . Weight saving was kept in consideration even throughout the interior and the seats also weighed each besides having adjustment motors. The dashboard featured an LCD console displaying vital information about the car and buttons arranged in a vertical way on the binnacle harked back to the original Audi Quattro. The wheelbase was shortened by and the roof line was shortened by as compared to the RS5.


title: Audi Quattro

text: The Quattro four-wheel-drive system used in the concept was a rear-biased design utilising a two-stage differential distributing power front and aft through planetary gears.


title: Audi Quattro

text: The concept utilised carbon-ceramic braking system for improved stopping power. The car had a claimed acceleration time of 3.8 seconds.


title: Audi Quattro

text: It was reported that Audi was considering a limited production model (200–500 cars) based on the quattro concept. However, the idea of production was scrapped in favour of expanding the company's crossover range.


title: Audi Quattro

text: The Audi Sport quattro concept was unveiled at the 2013 Frankfurt Motor Show (IAA) to commemorate the 30th anniversary of the original Audi Sport quattro. The show car features angular flat C-pillars, as well as rectangular double headlights featuring Audi's Matrix LED technology, a spoiler at the lower edge of the rear window, rectangular tail lights, 21-inch wheels, carbon fibre-ceramic brake discs, bucket seats with integrated head restraints, multifunction sport steering wheel, two driving modes (race and setup) in virtual 3D displays, Audi MMI control unit, and air conditioning. The doors and fenders were made of aluminum, while the roof, hood, and the rear hatch were made of carbon fiber-reinforced polymer. The front suspension features five control arms per wheel while the rear has track-controlled trapezoidal link.


title: Audi Quattro

text: Power is from a 4.0 TFSI V8 engine rated at and , along with a disc-shaped electric motor rated at and (for combined a power output of and ), mated to an eight-speed tiptronic transmission. A liquid-cooled 14.1 kWh lithium-ion battery is located at the rear, and the range is claimed up to on electric power alone.


title: Audi Quattro

text: At the 2014 Geneva Motor Show, Audi presented the new 2014 Audi TT Quattro Sport Concept. It was powered by a 2.0 L four-cylinder TFSI engine generating a maximum power output of and of torque. The concept featured Audi's Quattro AWD system and an S Tronic dual-clutch transmission.


title: Audi Quattro

text: The original Audi Quattro competition car debuted in 1980, first as a development car, and then on a formal basis in the 1980 Jänner Rallye in Austria. Largely based on the bodyshell of the road-going Quattro models (in contrast to the forthcoming Group B cars), the engine of the original competition version produced approximately . In 1981, Michèle Mouton became the first female driver to win a world championship rally, piloting an Audi Quattro. Over the next three years, Audi would introduce the A1 and A2 evolutions of the Quattro in response to the new Group B rules, raising the power output of the turbocharged inline 5-cylinder engine to around .


title: Audi Quattro

text: The Quattro A1 debuted at the WRC 1983 season opener Monte Carlo Rally, and went on to win the Swedish Rally and the Rally Portugal in the hands of Hannu Mikkola. Driven by Stig Blomqvist, Mikkola and Walter Röhrl, the A2 evolution won a total of eight world rallies, three in 1983 and five in 1984. Two examples of the same car completely dominated the South African National Rally Championships during 1984 to 1988, with S.A. champion drivers Sarel van der Merwe and Geoff Mortimer.


title: Audi Quattro

text: In 1988, the Audi Ur-Quattro driven by Audi Tradition driver Luciano Viaro won the 13th Silvretta Classic Montafon.


title: Audi Quattro

text: The Audi Sport Quattro S1 was a variant of the Quattro developed for homologation for Group B rallying in 1984, and sold as a production car in limited numbers. It featured an all aluminium Inline-five engine with a bore x stroke of DOHC 4 valves per cylinder, Bosch LH Jetronic fuel injection and a KKK K27 turbocharger. The engine was slightly smaller than that of the standard Audi Quattro in terms of displacement in order to qualify for the 3-litre engine class after the 1.4 multiplication factor applied to turbocharged engines. In road-going form, the engine was capable of generating at 6,700 rpm and at 3,700 rpm, with the engine on the competition cars initially generating around .


title: Audi Quattro

text: The car in competition form also featured a body shell composed of carbon-kevlar and wider wheel arches, wider wheels (nine inches as compared to the Ur-Quattro's optional wheels), the steeper windscreen rake of the Audi 80 (requested by the Audi Sport rally team drivers to reduce internal reflections from the dashboard for improved visibility) and, most noticeably, a shorter wheelbase.


title: Audi Quattro

text: In addition to Group B competition in rallying, the Sport Quattro won the 1985 Pikes Peak International Hill Climb with Michèle Mouton in the driving seat, setting a record time in the process. 224 cars in total of this "short version" Sport Quattro were built, and were offered for sale for DM 203,850.


title: Audi Quattro

text: The Audi Sport Quattro S1 E2 was introduced at the end of 1985 as an update to the Audi Sport Quattro S1. The car featured an inline five-cylinder engine that displaced from a bore and stroke of and generated an officially quoted power output figure of . However, the turbocharger utilised a recirculating air system, with the aim of keeping the unit spinning at high rpm, when the driver closed the throttle, either to back off during cornering, or on gearshifts. This allowed the engine to resume full power immediately after the resumption of full throttle, reducing turbo lag. The actual power figure was in excess of at 8,000 rpm.


title: Audi Quattro

text: In addition to the improved power output, an aggressive aerodynamic kit was added that featured very distinctive wings and spoilers at the front and rear of the car to increase downforce. The weight was reduced to . The S1 could accelerate from 0- in 3.1 seconds. Some of the cars were supplied with a "power-shift gearbox", a forerunner of the DSG technology.


title: Audi Quattro

text: The S1 E2 made its debut at the 1985 Rally Argentina, with Blomqvist driving. This variant was successful in the rally circuit, with Röhrl and Christian Geistdörfer winning the 1985 San Remo Rally. A modified version of the E2, was also driven by Michèle Mouton. The S1 E2 would become the final Group B car produced by Audi, with the works team withdrawing from the Championship following the 1986 rally in Portugal. The final factory cars of 1986 were rated at . In 1987, the car won the Pikes Peak International Hill Climb driven by Walter Röhrl.


title: Audi Quattro

text: Audi Sport Quattro RS 002 - Sports prototype "Group S" was a rally car that was initially designed for the forthcoming Group S regulations for 1987. The car was tested by Walter Röhrl but it never raced; the Group S regulations were scrapped along with the Group B regulations after a number of accidents involving fatalities during the 1986 season.


title: Audi Quattro

text: The car has a longitudinal mid-engine layout and a four-wheel drive system. The car is displayed in the museum "Audi museum mobile" in Ingolstadt.


title: Audi Quattro

text: A red 1983 Quattro was driven by DCI Gene Hunt (played by Philip Glenister) in the television drama "Ashes to Ashes" (aired on BBC1 from 2008 to 2010). Two cars were used through the run of the series: the original, and a stunt car that was acquired for series 2. Both portrayed the same car. The original vehicle (also used in the "Children in Need" "Top Gear" crossover mini-episode) lacked a sunroof which was present on the car(s) used in series 2 and 3, hence a fake one was added for the sake of continuity.


title: Audi Quattro

text: The stunt car was written off for the jump in series 3, episode 1 by the director of that episode and used as a parts and interior shots car until it was shot up in the finale, leaving the original car intact


title: Audi Quattro

text: In the run-up to the 2010 general election, a campaign poster by the incumbent Labour Party government portrayed Conservative Party and opposition leader David Cameron as Gene Hunt sitting on the bonnet of the iconic red Audi Quattro and urged voters not to allow Cameron to take Britain "back to the 1980s" by electing his party into government amid fears that it would lead to a repeat of the social unrest and unemployment that Margaret Thatcher's Conservative government of that era oversaw. The image was then adopted by the Conservatives, with the slogan "Fire up the Quattro, it's time for change", with the comment 'Idea kindly donated by the Labour Party'. "Fire up the Quattro" was a call to action uttered by DCI Hunt in "Ashes to Ashes".


title: Human behavior

text: Human behavior is the potential and expressed capacity (mentally, physically, and socially) of human individuals or groups to respond to internal and external stimuli throughout their life. Behavior is driven by genetic and environmental factors that affect an individual. Behavior is also driven, in part, by thoughts and feelings, which provide insight into individual psyche, revealing such things as attitudes and values. Human behavior is shaped by psychological traits, as personality types vary from person to person, producing different actions and behavior.


title: Human behavior

text: Social behavior accounts for actions directed at others. It is concerned with the considerable influence of social interaction and culture, as well as ethics, interpersonal relationships, politics, and conflict. Some behaviors are common while others are unusual. The acceptability of behavior depends upon social norms and is regulated by various means of social control. Social norms also condition behavior, whereby humans are pressured into following certain rules and displaying certain behaviors that are deemed acceptable or unacceptable depending on the given society or culture.


title: Human behavior

text: Cognitive behavior accounts for actions of obtaining and using knowledge. It is concerned with how information is learned and passed on, as well as creative application of knowledge and personal beliefs such as religion. Physiological behavior accounts for actions to maintain the body. It is concerned with basic bodily functions as well as measures taken to maintain health. Economic behavior accounts for actions regarding the development, organization, and use of materials as well as other forms of work. Ecological behavior accounts for actions involving the ecosystem. It is concerned with how humans interact with other organisms and how the environment shapes human behavior.


title: Human behavior

text: Human behavior is studied by the social sciences, which include psychology, sociology, ethology, and their various branches and schools of thought. The study of human behavior includes how the human mind evolved and how the nervous system controls behavior. The nature versus nurture debate considers how behavior is affected by genetic and environmental factors. Philosophy of mind considers aspects such as free will, the mind–body problem, and malleability of human behavior. The study of human behavior sometimes receives public attention due to its intersection with cultural issues, including crime, sexuality, and social inequality.


title: Human behavior

text: Twin studies are a common method by which human behavior is studied. Twins with identical genomes can be compared to isolate genetic and environmental factors in behavior. Lifestyle, susceptibility to disease, and unhealthy behaviors have been identified to have both genetic and environmental indicators through twin studies.


title: Human behavior

text: Human social behavior is the behavior that considers other humans, including communication and cooperation. It is highly complex and structured, based on advanced theory of mind that allows humans to attribute thoughts and actions to one another. Through social behavior, humans have developed society and culture distinct from other animals. Human social behavior is governed by a combination of biological factors that affect all humans and cultural factors that change depending on upbringing and societal norms. Human communication is based heavily on language, typically through speech or writing. Nonverbal communication and paralanguage can modify the meaning of communications by demonstrating ideas and intent through physical and vocal behaviors.


title: Human behavior

text: Human behavior in a society is governed by social norms. Social norms are unwritten expectations that members of society have for one another. These norms are ingrained in the particular culture that they emerge from, and humans often follow them unconsciously or without deliberation. These norms affect every aspect of life in human society, including decorum, social responsibility, property rights, contractual agreement, morality, justice, and meaning. Many norms facilitate coordination between members of society and prove mutually beneficial, such as norms regarding communication and agreements. Norms are enforced by social pressure, and individuals that violate social norms risk social exclusion.