Ultra-Wideband Antenna Design for GPR Applications: A Review
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paper_title: Improved ultra-wide bandwidth bow-tie antenna with metamaterial lens for GPR applications

paper_content:

A new resistively loaded bow-tie antenna which can operate from 300 MHz to more than 3 GHz bandwidth is proposed. The proposed antenna employs a metamaterial lens to improve the forward gain and front-to-back ratio. The antenna radiates pulses with minimal late-time ringing and high peak amplitude. A stable radiation pattern obtained from 300 MHz to 2 GHz, makes it suitable for time domain as well as stepped frequency continuous wave (SFCW) GPR applications. The antenna is characterized by measurements of return loss, transmission scattering parameter, radiation pattern, gain, front-to-back ratio, and GPR B-scan with object buried under soil. The measured results are in good agreement with the simulation results.
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paper_title: Simple notches design for ultra-wideband monopole antennas with coplanar-waveguide-coupled-fed

paper_content:

In this article, the design of a ultra-wideband (UWB) monopole antenna with coplanar-waveguide (CPW)-coupled-fed is presented. The antenna is composed of a trapezium patch with a CPW-fed printed on one side of the substrate and an elliptical radiator on the other side. By simply cutting slits on the radiation patch, a single, dual, and triple band notched characteristics can be achieved. Parametric studies on the antenna and slits are carried out by computer simulation. Results show that the notch frequencies can be set by using dimensions of the slits. The antennas are designed and optimized using computer simulation. For verification, the antennas with single and dual band-notched characteristics are fabricated and measured. The simulated and measured results on the return loss, radiation pattern, peak gain, and efficiency of the antenna are presented. Due to the small ground-plane size of the antenna, the feeding cable used in the measurement equipment significantly affects the measured results and leads to large discrepancies between the simulated and measured results at low frequencies. To study this, the simulation model of the feeding cable is also used in simulation and results show that the discrepancies are substantially reduced. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1017–1027, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27530
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paper_title: Compact UWB Bandpass Filter With Dual Notch Bands Using Open Circuited Stubs

paper_content:

In this letter, an ultra-wideband (UWB) bandpasss filter with multiple notch bands is presented. The UWB bandpass characteristic is achieved using a modified distributed highpass filter (HPF) and suppressing higher order harmonics of the HPF by realizing defected stepped impedance resonator. The dual band notches at 5.75 and 8.05 GHz are obtained by embedding two open stubs on the main microstrip line. The in band and out of band performance obtained from fullwave electromagnetic simulation, equivalent circuit model and measurement are in good agreement.
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paper_title: Increasing the gain of a semicircular slot UWB antenna using an FSS reflector

paper_content:

In this paper we demonstrate the gain enhancement of a semicircular slot antenna using a multilayer frequency-selective surface (FSS). A theoretical analysis of the FSS with a UWB semicircular slot antenna is presented. The multilayer FSS provides an appropriate reflection phase to act as a reflector and is able to enhance the gain of the slot antenna. Simulations show a linear phase response from 3.5 GHz to 12 GHz that is sufficient for ultra wideband operation. A significant improvement of 3 to 4 dB gain over the whole frequency range is demonstrated. The composite antenna has a theoretical gain of 8 dBi and a very small maximum gain variation of ±1.5 dB over the 3.5 to 10 GHz frequency range. Its compact configuration provides flexibility for mounting the reflector close to the slot antenna and makes it more suitable for modern UWB devices.
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paper_title: Novel shapes of Vivaldi antenna for ground pentrating radar (GPR)

paper_content:

Novel planar Vivaldi antenna with better performance compared to conventional TEM horn antenna is introduced. An exponential tapered slot edge (TSE) structure is employed. Electromagnetic band gap structure as seven pair of loop or square shaped defected ground structure is added to the ground antenna plane. The proposed shape has the advantage of extending the low-end bandwidth limit due to improving the antenna matching especially at low frequency and reduced the electrical length of the antenna by 45% compared to the original antenna size.
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paper_title: Ultra-Wideband Differential Bandpass Filter With Narrow Notched Band and Improved Common-Mode Suppression by DGS

paper_content:

A novel microstrip ultra-wideband (UWB) differential filter with narrow notched band based on the transversal signal- interference concept is presented. In order to enhance the interference immunity from undesired signals efficiently, the notched band is implemented by coupling with quarter wavelength shorted-line at input and output ports. By taking advantage of the bandgap characteristic of defected ground structure (DGS), a slot-line DGS is used for improving the common-mode rejection. In this work, at the center frequency of the notched band which is 2.45 GHz, about 7.3% bandwidth (2.35-2.53 GHz) is realized by full-wave simulator. Agreement between experiment and simulation is observed.
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paper_title: UWB antennas for ground penetrating radar application

paper_content:

Presented paper describes results of comparison study on antennas for ground penetrating radar (GPR, undersurface radar) operating in frequency band from 500 MHz to 3 GHz. Typical representatives of elementary antennas, planar monopoles, dipole antennas, tapered slot antennas, TEM horns and frequency independent antennas are firstly optimized for the operation band in CST design environment. Then structures are described and compared from the impedance, radiation and time characteristic point of view to enable a simple choice of suitable structures for manufacture. Selected antennas are prepared for the manufacture and comparison with their models.
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paper_title: Design and optimization of ultra-wideband TEM horn antennas for GPR applications

paper_content:

This paper presents the design and optimization of ultra-wideband (UWB) transverse electromagnetic (TEM) horn antennas for ground penetrating radar (GPR) applications. The numerical simulations of electromagnetic wave propagation are performed in the time domain for a preliminary and modified TEM horn antenna. The TEM horn antennas have some reflections and ringing which are not suitable for GPR applications. These effects are reduced by optimization of the antenna structure. The time domain characteristic and voltage standing wave ratio (VSWR) of the antennas are computed. The optimized TEM horn antenna is then modeled with the typical GPR environment with earth, and the hidden object inside the earth. The presented antenna can be used in the GPR systems to detect and image buried objects, and for the characterization of the non-homogeneous layered structure.
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paper_title: Quad ridged UWB TEM horn antenna for GPR applications

paper_content:

A compact quad-ridged horn antenna (QRH) for the deep ground penetrating radar water detection applications is designed operate in frequency range of 50MHz to 500MHz. Within this contribution the design and simulation of such an antenna is considered for water level detection in Egyptian dessert aquifers. Among the varying horn design parameters, the linear and exponentially tapered walls are studied as well as variations of the curvature of the dielectric waveguide between the two ridges enhancing the matching conditions hence, reducing size and increasing the antenna operational bandwidth. The design goal is to achieve broad bandwidth antenna with maintaining compact dimensions. Two modifications have been introduced on the conventional triangular TEM horn antenna. First multifunction tapering of the horn plates with curvature ending, second inserting perturbing two different ridges between the aperture planes and filling the space between the ridges with high dielectric constant material, in order to lower the operating frequency without increasing the size of the original setup. Replacing the two ridges with four ones, each pair is perpendicular to the other, reduces more the antenna size and improves more its matching. The antenna dimensions are 145 × 102 × 124 cm ::: 3 ::: that resembles improvement in size as compared with similar commercial GPR horn antennas as Satimo Horn model SH 68 with dimensions 2983×1615×2505 cm ::: 3 ::: .
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paper_title: in situ measurement of pavement thickness and dielectric permittivity by GPR using an antenna array

paper_content:

Abstract We present a ground penetrating radar (GPR) system, which uses an antenna array for in situ measurements of the thickness and dielectric permittivity of an asphalt pavement layer. We calibrated the antenna array by considering the antenna phase center and the antenna offset. The results of the laboratory measurements demonstrate that the proposed calibration method can greatly improve the accuracy of the velocity and thickness estimations when compared with the conventional method. A field measurement conducted on a highway pavement shows that the error of the thickness estimation of the asphalt layer is less than 6 mm (10%).
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paper_title: Ultra Wide Band horn antenna design for Ground Penetrating Radar: A feeder practice

paper_content:

Ultra-Wide Band (UWB) technology in Ground Penetrating Radar (GPR) imaging has been an interested research topic for the last couple of decades. Although there have been a lot of work and research conducted on this subject, there c still interested research matters that has to be studied. UWB directional antennas are one of the critical components for UWB-GPR applications. The parameters of the antennas that are used within the system affect the performance of the application. The horn antenna; for example, can give the focusing ability needed in some applications thanks to its high directivity feature. Although there are many parameters that affect the design of a Horn antenna, aperture size and the feeder type are commonly used parameters to obtain wider frequency operation. In this study, the effect of different feeding structures on frequency bandwidth for a fixed waveguide dimensions are investigated and the results are shared. For this purpose, various feeding structures that are straight wire feeder, spherical feeder, cylindrical feeder and conical feeder are examined and the simulated and the measured bandwidth results are presented. Furthermore, we propose a new feeder type that provides better simulation results in terms of bandwidth is introduced. With this new structure, the horn antenna is optimized using an antenna simulation software; CST-Microwave Studio and the corresponding produced antenna is measured to complete the design.
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paper_title: A Novel Compact Double Exponentially Tapered Slot Antenna (DETSA) for GPR Applications

paper_content:

A novel compact double exponentially tapered slot antenna (DETSA) for GPR applications is presented. To extend the antenna's impedance bandwidth, the antenna arms are rolled back and lengthened, and lumped resistors are used near the ends of the rolled arms. An improved coplanar waveguide (CPW) to coupled stripline (CPS) transition for feeding is also investigated. The measured transmission loss of two back-to-back CPW-to-CPS transitions is less than 2.6 dB in the frequency band of 200 MHz-6 GHz, which agrees well with the simulated result. The measured S11 of the antenna in frequency domain is less than -10 dB in the band of 220 MHz-6 GHz, and it is also verified that the resistors mainly have influence on the antenna's S11 below 1 GHz. The measured reflected pulses show that there are only two reflecting points, and the reflection is weak. The simulated and measured antenna gains at boresight show little variations with loading resistors of different values, and this means that the resistive loadings do not affect the gain characteristics of the antenna. The antenna's transmission re- sponse in time domain is also tested, and its application in GPR detection of a buried target is validated by experiments.
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paper_title: Design of UWB Antenna for Air-Coupled Impulse Ground-Penetrating Radar

paper_content:

This letter presents a new transverse electromagnetic flared horn antenna for the demanding requirement of an air-coupled impulse ground-penetrating radar. Structure anatomy is performed focusing on achieving good impedance matching throughout the wide frequency band. The design procedure starts with constructing an analytic model to evaluate the preliminary physical dimensions to achieve minimum reflections. Structural fine tunings are then performed for optimization. The antennas are fabricated and tested. Experimental results validate the design effectiveness.
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paper_title: Improved ultra-wide bandwidth bow-tie antenna with metamaterial lens for GPR applications

paper_content:

A new resistively loaded bow-tie antenna which can operate from 300 MHz to more than 3 GHz bandwidth is proposed. The proposed antenna employs a metamaterial lens to improve the forward gain and front-to-back ratio. The antenna radiates pulses with minimal late-time ringing and high peak amplitude. A stable radiation pattern obtained from 300 MHz to 2 GHz, makes it suitable for time domain as well as stepped frequency continuous wave (SFCW) GPR applications. The antenna is characterized by measurements of return loss, transmission scattering parameter, radiation pattern, gain, front-to-back ratio, and GPR B-scan with object buried under soil. The measured results are in good agreement with the simulation results.
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paper_title: A 900MHz shielded bow-tie antenna system for ground penetrating radar

paper_content:

A back-cavity shielded bow-tie antenna system working at 900MHz center frequency for ground-coupled GPR application is investigated numerically and experimentally in this paper. Bow-tie geometrical structure is modified for a compact design and back-cavity assembly. A layer of absorber is employed to overcome the back reflection by omni-directional radiation pattern of a bow-tie antenna in H-plane, thus increasing the SNR and improve the isolation between T and R antennas as well. The designed antenna system is applied to a prototype GPR system. Tested data shows that the back-cavity shielded antenna works satisfactorily in the 900MHz GPR system.
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paper_title: Design and simulation of compact UWB Bow-tie antenna with reduced end-fire reflections for GPR applications

paper_content:

The efficiency of the ground penetrating radar (GPR) system significantly depends on the antenna performance as signal has to propagate through lossy and inhomogeneous media. In this research work a resistively loaded compact Bow-tie antenna which can operate through a wide bandwidth of 4.1 GHz is proposed. The sharp corners of the slot antenna are rounded so as to minimize the end-fire reflections. The proposed antenna employs a resistive loading technique through a thin sheet of graphite to attain the ultra-wide bandwidth. The simulated results obtained from CST Microwave Studio v14 and HFSS v14 show a good amount of agreement for the antenna performance parameters. The proposed antenna has potential to apply for the GPR applications as it provides improved radiation efficiency, enhanced bandwidth, gain, directivity and reduced end-fire reflections.
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paper_title: Wide band coplanar waveguide-fed bowtie slot antenna for a large range of ground penetrating radar applications

paper_content:

For the non-destructive sounding of the sub-surface for a large range of applications, a coplanar waveguide-fed bowtie slot antenna operating in a wide frequency band [0.4;1.5] GHz has been designed. The main originality of our work is the extension of the operating frequency band of the uniplanar bowtie slot antenna to frequencies lower than 800 MHz. The shape and the dimensions of the antenna have been optimised in the presence of a soil using numerical simulations based on the finite difference time domain approach. For the characterisation of the sub-surface, a transmission link comprising a pair of bowtie slot antennas that are moved along the soil surface has been studied in details to obtain the system performance in the frequency and time domains. First experimental results have been obtained on a sandy soil in the frequency domain using a vector network analyser. The experimental data have been analysed and compared with simulations results.
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paper_title: Design of a low cost cavity backed wideband bow-tie antenna for ground penetrating radar systems

paper_content:

The ground penetrating radar (GPR) designs demand antennas with ultra wide bandwidths (UWB). Thus the conventional antennas such as dipoles cannot be used effectively. The GPR antennas are expensive. In this paper, the feasibility of building a low cost ultra-wide band bow-tie antenna for GPR using widely available low cost materials such as FR-4 PCB substrates, low cost TV baluns and scrap iron is explored. The objective was to develop the antenna to radiate in the range from 200 MHz to 600 MHz whilst restricting the antenna lobes to the direction of the ground. A cavity backed design is considered to obtain these requirements. The antenna was modeled using Ansoft HFSS (presently Ansys HFSS) software package which is widely used in current industrial domain. The simulations were carried out for different antenna configurations by changing its parameters according to linear programming techniques. Further, electromagnetic interferences (EMI) have been successfully reduced by integrating a metal cavity which acts as a reflector to the antenna. Parameters related to the cavity were tweaked in order to obtain the optimum frequency response. Considering the simulation results the most satisfactory antenna configuration was obtained and implemented.
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paper_title: UWB antennas for ground penetrating radar application

paper_content:

Presented paper describes results of comparison study on antennas for ground penetrating radar (GPR, undersurface radar) operating in frequency band from 500 MHz to 3 GHz. Typical representatives of elementary antennas, planar monopoles, dipole antennas, tapered slot antennas, TEM horns and frequency independent antennas are firstly optimized for the operation band in CST design environment. Then structures are described and compared from the impedance, radiation and time characteristic point of view to enable a simple choice of suitable structures for manufacture. Selected antennas are prepared for the manufacture and comparison with their models.
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paper_title: Semicircular Slot-Tuned Planar Half-Ellipse Antenna With a Shallow Vee-Cavity in Vital Sign Detection

paper_content:

Ultrawideband (UWB) antenna is one critical part of the impulse radar system. In this paper, a shallow Vee-cavity shielded planar dipole antenna working at the center frequency of 400 MHz for UWB vital sign detection radar is investigated numerically and experimentally. It consists of two half-ellipse-shape arms tuned with four semicircular slots and a shallow Vee-cavity. The voltage standing wave ratio (VSWR), input impedance, and radiation waveforms are all analyzed. The resistive and slot loading techniques for improving impulse radiation and reducing late-time ringing are adopted. Several important parameters of the designed antenna have been studied. The influence of a shallow rectangular cavity and the proposed Vee-cavity on the antenna characteristics is also under consideration. Finally, one prototype antenna is fabricated and applied to UWB vital sign detection radar system. The experimental results indicate that the proposed half-ellipse antenna with a Vee-cavity works satisfactorily in the radar system.
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paper_title: DESIGN OF A BALUN FOR A BOW TIE ANTENNA IN RECONFIGURABLE GROUND PENETRATING RADAR SYSTEMS

paper_content:

DESIGN OF A BALUN FOR A BOW TIE ANTENNA INRECONFIGURABLE GROUND PENETRATING RADARSYSTEMSR. PersicoIstituto per il Beni Archeologici e MonumentaliConsiglio Nazionale delle RicercheVia Monteroni, Campus Universitario, Lecce 73100, ItalyN. RomanoDipartimento di Ingegneria dell’InformazioneSeconda Universitµa degli studi di NapoliVia Roma 29, Aversa 81031, ItalyF. SoldovieriIstituto per il Rilevamento Elettromagnetico dell’AmbienteConsiglio Nazionale delle RicercheVia Diocleziano 328, Napoli 80124, ItalyAbstract|This paper deals with the design of a reconﬂgurableantenna that resembles a monolithic UWB bow-tie antenna for GroundPenetrating Radar (GPR) applications. In particular, the attentionis focussed on the design of the balun system able to work in thefrequency band 0.3{1GHz; the eﬁectiveness of the design is shown byexamining the behaviour of the scattering parameters
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paper_title: Frontiers in Antennas: Next Generation Design & Engineering

paper_content:

Chapter 1 Ultra-Wideband Antenna Arrays Chapter 2 Smart Antennas Chapter 3 Vivaldi Antenna Arrays Chapter 4 Artificial Magnetic Conductors/High Impedance Surfaces Chapter 5 Metamaterial Antennas Chapter 6 Biological Antenna Design Methods Chapter 7 Reconfigurable Antennas Chapter 8 Antennas in Medicine: Ingestible Capsule Antennas Chapter 9 Leaky-Wave Antennas Chapter 10 Plasma Antennas Chapter 11 Numerical Methods in Antenna Modeling
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paper_title: A novel wide beam UWB antenna design for Through-the-Wall radar

paper_content:

This paper presents a novel wide beam UWB antennae design for Impulse Radio-Ultra Wide Band (IR-UWB) Through-the-Wall detection radar. The design is based on a typical bowtie slot antenna structure with an added reflector in order to achieve unidirectionality and wide beam. The effects of different parameters of the added reflector on the impedance and radiation characteristics are analyzed. The different structural parameters of antenna are optimized by numerical simulations. Simulated and measured results show that the front-to-back ratio is great than 10dB and the beam width is approximately 120° ~145 ° within operation band for |S11|<-10dB (0.8GHz~2.3GHz).
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paper_title: An antipodal Vivaldi antenna for ultra-wideband system

paper_content:

Vivaldi antenna is a traditional ultra-wideband(UWB) antenna, and this paper focuses on designing its structural parameters properly to balance the bandwidth, gain, cross-polarization and other key parameters. By studying the effects of various parameters on the antenna performance, a compact Vivaldi antenna for ultra-wideband system is designed and realized. The antenna has a small size, high gain and small cross-polarization characteristics compared with the antannas in the relevant references, and it can meet the requirements of UWB system.
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paper_title: Simple notches design for ultra-wideband monopole antennas with coplanar-waveguide-coupled-fed

paper_content:

In this article, the design of a ultra-wideband (UWB) monopole antenna with coplanar-waveguide (CPW)-coupled-fed is presented. The antenna is composed of a trapezium patch with a CPW-fed printed on one side of the substrate and an elliptical radiator on the other side. By simply cutting slits on the radiation patch, a single, dual, and triple band notched characteristics can be achieved. Parametric studies on the antenna and slits are carried out by computer simulation. Results show that the notch frequencies can be set by using dimensions of the slits. The antennas are designed and optimized using computer simulation. For verification, the antennas with single and dual band-notched characteristics are fabricated and measured. The simulated and measured results on the return loss, radiation pattern, peak gain, and efficiency of the antenna are presented. Due to the small ground-plane size of the antenna, the feeding cable used in the measurement equipment significantly affects the measured results and leads to large discrepancies between the simulated and measured results at low frequencies. To study this, the simulation model of the feeding cable is also used in simulation and results show that the discrepancies are substantially reduced. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1017–1027, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27530
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paper_title: A Printed Vivaldi Antenna with Improved Radiation Patterns by Using Two Pairs of Eye-Shaped Slots for UWB Applications

paper_content:

In this paper, a printed Vivaldi antenna with two pairs of eye-shaped slots is proposed for UWB applications. By using two pairs of eye-shaped slots, the side lobe levels of the radiation pattern are reduced, and the antenna gain is improved at low frequencies. To illustrate the efiectiveness of the proposed design, a prototype of the proposed antenna is fabricated and measured. Experimental results show that the proposed antenna presents a measured impedance bandwidth, deflned by jS11j < i10dB, from 3 to 12.8GHz with a compact size (36mm£36mm). Good unidirectional radiation characteristics with a front-to-back ratio better than 10dB are also achieved. The measured gain is better than 3.7dBi in the operating frequency band. In addition, the measured group delay of the proposed antenna is around 1.2ns with a variation less than §0:5ns.
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paper_title: Novel shapes of Vivaldi antenna for ground pentrating radar (GPR)

paper_content:

Novel planar Vivaldi antenna with better performance compared to conventional TEM horn antenna is introduced. An exponential tapered slot edge (TSE) structure is employed. Electromagnetic band gap structure as seven pair of loop or square shaped defected ground structure is added to the ground antenna plane. The proposed shape has the advantage of extending the low-end bandwidth limit due to improving the antenna matching especially at low frequency and reduced the electrical length of the antenna by 45% compared to the original antenna size.
---
paper_title: Ultra-Wideband Differential Bandpass Filter With Narrow Notched Band and Improved Common-Mode Suppression by DGS

paper_content:

A novel microstrip ultra-wideband (UWB) differential filter with narrow notched band based on the transversal signal- interference concept is presented. In order to enhance the interference immunity from undesired signals efficiently, the notched band is implemented by coupling with quarter wavelength shorted-line at input and output ports. By taking advantage of the bandgap characteristic of defected ground structure (DGS), a slot-line DGS is used for improving the common-mode rejection. In this work, at the center frequency of the notched band which is 2.45 GHz, about 7.3% bandwidth (2.35-2.53 GHz) is realized by full-wave simulator. Agreement between experiment and simulation is observed.
---
paper_title: in situ measurement of pavement thickness and dielectric permittivity by GPR using an antenna array

paper_content:

Abstract We present a ground penetrating radar (GPR) system, which uses an antenna array for in situ measurements of the thickness and dielectric permittivity of an asphalt pavement layer. We calibrated the antenna array by considering the antenna phase center and the antenna offset. The results of the laboratory measurements demonstrate that the proposed calibration method can greatly improve the accuracy of the velocity and thickness estimations when compared with the conventional method. A field measurement conducted on a highway pavement shows that the error of the thickness estimation of the asphalt layer is less than 6 mm (10%).
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paper_title: Directivity Improvement of Vivaldi Antenna Using Double-Slot Structure

paper_content:

The conventional Vivaldi antenna is known for its ultrawideband characteristic, but low directivity. In order to improve the directivity, a double-slot structure is proposed to design a new Vivaldi antenna. The two slots are excited in uniform amplitude and phase by using a T-junction power divider. The double-slot structure can generate plane-like waves in the E-plane of the antenna. As a result, directivity of the double-slot Vivaldi antenna is significantly improved by comparison to a conventional Vivaldi antenna of the same size. The measured results show that impedance bandwidth of the double-slot Vivaldi antenna is from 2.5 to 15 GHz. Gain and directivity of the proposed antenna is considerably improved at the frequencies above 6 GHz. Furthermore, the main beam splitting at high frequencies of the conventional Vivaldi antenna on thick dielectric substrates is eliminated by the double-slot structure.
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paper_title: A Compact Antipodal Vivaldi Antenna for UWB Applications

paper_content:

A compact antipodal Vivaldi antenna (AVA) with the dimension of $42 \times 36 \times 1.6~\hbox{mm}{^3}$ is proposed in this letter. Structural modifications in the radiating fins have increased the electrical length thereby reducing the lower operating frequency from 5.2 GHz to 3.7 GHz. Proposed antenna maintains $-20~\hbox{dB}$ copolarization to cross-polarization ratio throughout the operating bandwidth. The prototype is fabricated and the measurement results are presented to validate the performance of the proposed AVA.
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paper_title: Frontiers in Antennas: Next Generation Design & Engineering

paper_content:

Chapter 1 Ultra-Wideband Antenna Arrays Chapter 2 Smart Antennas Chapter 3 Vivaldi Antenna Arrays Chapter 4 Artificial Magnetic Conductors/High Impedance Surfaces Chapter 5 Metamaterial Antennas Chapter 6 Biological Antenna Design Methods Chapter 7 Reconfigurable Antennas Chapter 8 Antennas in Medicine: Ingestible Capsule Antennas Chapter 9 Leaky-Wave Antennas Chapter 10 Plasma Antennas Chapter 11 Numerical Methods in Antenna Modeling
---
paper_title: Frontiers in Antennas: Next Generation Design & Engineering

paper_content:

Chapter 1 Ultra-Wideband Antenna Arrays Chapter 2 Smart Antennas Chapter 3 Vivaldi Antenna Arrays Chapter 4 Artificial Magnetic Conductors/High Impedance Surfaces Chapter 5 Metamaterial Antennas Chapter 6 Biological Antenna Design Methods Chapter 7 Reconfigurable Antennas Chapter 8 Antennas in Medicine: Ingestible Capsule Antennas Chapter 9 Leaky-Wave Antennas Chapter 10 Plasma Antennas Chapter 11 Numerical Methods in Antenna Modeling
---
paper_title: A compact double-ridged horn antenna for ground penetrating radar applications

paper_content:

A compact double-ridged horn antenna for ground penetrating radar applications in the frequency range of 1–7 GHz will be presented in this work. Within this contribution the design, simulation and fabrication of such an antenna will be considered. Among the varying design parameters are linear and exponentially tapered walls as well as variations of the curvature of the dielectric waveguide between the two ridges. In addition an absorber structure and a complex shaped metallic back plate have been introduced to further improve the return loss. The primary design goal is a broad bandwidth while maintaining compact dimensions. Two modifications have been introduced in this antenna design in contrast to the standard TEM horn. By protruding the ridges from the aperture plane and filling the space between the ridges with dielectric material it is possible to lower the operating frequency without increasing the size of the original setup. The proposed design has been applied to subsurface radar application in both, field simulations by means of CST Microwave Studio and measurement in a GPR test scenario. The fabricated antenna has been verified by anechoic chamber measurements. The performance of the antenna with respect to the detection of subsurface objects will be verified by various experiments.
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paper_title: Design of Transverse Electromagnetic Horn for Concrete Penetrating Ultrawideband Radar

paper_content:

We propose a design for the specific class of trans- verse electromagnetic (TEM) horn that can effectively radiate the electromagnetic signals into soil or concrete. The designed horn antenna has the same aperture height and width, resulting in a square-shaped horn aperture. A design guideline for the horn that considers return loss and radiation performance is described in this paper. The proposed TEM horn is constructed and measured to validate the design. The constructed horn has a maximum dimension (including the balun) of 42.9 × 26.8 × 20 cm. Simulated and measured results suggest that the proposed horn is more effective in radiating electromagnetic energy into concrete, compared with existing TEM horn designs. For free space radiation, measured operating bandwidth of the horn is 0.75-12.0 GHz, with a gain of 3-13 dBi. When radiated into a concrete block, measured operating bandwidth of the horn is 1.0-12.0 GHz.
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paper_title: UWB antennas for ground penetrating radar application

paper_content:

Presented paper describes results of comparison study on antennas for ground penetrating radar (GPR, undersurface radar) operating in frequency band from 500 MHz to 3 GHz. Typical representatives of elementary antennas, planar monopoles, dipole antennas, tapered slot antennas, TEM horns and frequency independent antennas are firstly optimized for the operation band in CST design environment. Then structures are described and compared from the impedance, radiation and time characteristic point of view to enable a simple choice of suitable structures for manufacture. Selected antennas are prepared for the manufacture and comparison with their models.
---
paper_title: Design and optimization of ultra-wideband TEM horn antennas for GPR applications

paper_content:

This paper presents the design and optimization of ultra-wideband (UWB) transverse electromagnetic (TEM) horn antennas for ground penetrating radar (GPR) applications. The numerical simulations of electromagnetic wave propagation are performed in the time domain for a preliminary and modified TEM horn antenna. The TEM horn antennas have some reflections and ringing which are not suitable for GPR applications. These effects are reduced by optimization of the antenna structure. The time domain characteristic and voltage standing wave ratio (VSWR) of the antennas are computed. The optimized TEM horn antenna is then modeled with the typical GPR environment with earth, and the hidden object inside the earth. The presented antenna can be used in the GPR systems to detect and image buried objects, and for the characterization of the non-homogeneous layered structure.
---
paper_title: Quad ridged UWB TEM horn antenna for GPR applications

paper_content:

A compact quad-ridged horn antenna (QRH) for the deep ground penetrating radar water detection applications is designed operate in frequency range of 50MHz to 500MHz. Within this contribution the design and simulation of such an antenna is considered for water level detection in Egyptian dessert aquifers. Among the varying horn design parameters, the linear and exponentially tapered walls are studied as well as variations of the curvature of the dielectric waveguide between the two ridges enhancing the matching conditions hence, reducing size and increasing the antenna operational bandwidth. The design goal is to achieve broad bandwidth antenna with maintaining compact dimensions. Two modifications have been introduced on the conventional triangular TEM horn antenna. First multifunction tapering of the horn plates with curvature ending, second inserting perturbing two different ridges between the aperture planes and filling the space between the ridges with high dielectric constant material, in order to lower the operating frequency without increasing the size of the original setup. Replacing the two ridges with four ones, each pair is perpendicular to the other, reduces more the antenna size and improves more its matching. The antenna dimensions are 145 × 102 × 124 cm ::: 3 ::: that resembles improvement in size as compared with similar commercial GPR horn antennas as Satimo Horn model SH 68 with dimensions 2983×1615×2505 cm ::: 3 ::: .
---
paper_title: Ultra Wide Band horn antenna design for Ground Penetrating Radar: A feeder practice

paper_content:

Ultra-Wide Band (UWB) technology in Ground Penetrating Radar (GPR) imaging has been an interested research topic for the last couple of decades. Although there have been a lot of work and research conducted on this subject, there c still interested research matters that has to be studied. UWB directional antennas are one of the critical components for UWB-GPR applications. The parameters of the antennas that are used within the system affect the performance of the application. The horn antenna; for example, can give the focusing ability needed in some applications thanks to its high directivity feature. Although there are many parameters that affect the design of a Horn antenna, aperture size and the feeder type are commonly used parameters to obtain wider frequency operation. In this study, the effect of different feeding structures on frequency bandwidth for a fixed waveguide dimensions are investigated and the results are shared. For this purpose, various feeding structures that are straight wire feeder, spherical feeder, cylindrical feeder and conical feeder are examined and the simulated and the measured bandwidth results are presented. Furthermore, we propose a new feeder type that provides better simulation results in terms of bandwidth is introduced. With this new structure, the horn antenna is optimized using an antenna simulation software; CST-Microwave Studio and the corresponding produced antenna is measured to complete the design.
---
paper_title: Design of UWB Antenna for Air-Coupled Impulse Ground-Penetrating Radar

paper_content:

This letter presents a new transverse electromagnetic flared horn antenna for the demanding requirement of an air-coupled impulse ground-penetrating radar. Structure anatomy is performed focusing on achieving good impedance matching throughout the wide frequency band. The design procedure starts with constructing an analytic model to evaluate the preliminary physical dimensions to achieve minimum reflections. Structural fine tunings are then performed for optimization. The antennas are fabricated and tested. Experimental results validate the design effectiveness.
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paper_title: Multioctave Frequency Selective Surface Reflector for Ultrawideband Antennas

paper_content:

In this letter, we demonstrate the gain enhancement of an ultrawideband (UWB) antenna, achieved using an appropriately designed multioctave dual-layer frequency selective surface (FSS) reflector. The proposed novel FSS reflects effectively in phase over a bandwidth of about 120%. Hence, significant enhancement in antenna gain has been achieved with a low-profile configuration without compromising the impedance bandwidth of the UWB antenna. The proposed FSS reflector has a low transmission coefficient and linearly decreasing phase over an ultra-wide frequency band, which is the key requirement for providing an effectively in-phase reflection at the antenna plane. The composite structure is compact, with a total height of λ/4, where λ is the free-space wavelength at the lowest operating frequency of 3 GHz. Experimental results show an impedance bandwidth of 122%. The antenna gain is maintained around 7.5 dBi from 3 to 7 GHz. Between 7-14 GHz, the antenna is more directive with a gain of about 9 dBi with ±0.5 dB variation. Experimental measurements con firm the predicted wideband antenna performance and gain enhancement due to the FSS reflector.
---
paper_title: A UWB monopole antenna for GPR application

paper_content:

In this paper the design of an ultra-wideband (UWB) monopole antenna with a coplanar waveguide (CPW) feed for ground penetrating radar (GPR) application is presented. The antenna offers a broad bandwidth from 0.4 to 3 GHz with a relative small GPR antenna size compared to the conventional circular monopole antenna. The other advantages of such an antenna are the simple antenna structure and easy to be integrated with PCB board. A rectangular conducting reflector is placed below the antenna to obtain a unidirectional radiation pattern for GPR application. Computer simulations are conducted and measurements are carried out to validate the results.
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paper_title: Compact Planar Ultra-wideband Antenna with Wireless Local Area Network and X Band Notches

paper_content:

AbstractA microstrip-fed ultra-wideband antenna with dual band-rejection characteristics is investigated. The antenna has the same shape between radiation patch and ground plane, and is fabricated on a Rogers RT/duroid 5880 substrate with an overall size of 22×31.85×0.508 mm3 . To generate two notched frequency bands, a U-shaped parasitic element on the back of the patch is utilized. The two notched bands can be controlled by adjusting the size of the parasitic element. The measured results show that the proposed antenna has an impedance bandwidth of 3.0 to 11.7 GHz for S11 <蜢10 dB, expects two eliminated frequency bands 5.08~5.96 GHz for wireless local area network and 8.71~10.25 GHz for X-band.
---
paper_title: Novel shapes of Vivaldi antenna for ground pentrating radar (GPR)

paper_content:

Novel planar Vivaldi antenna with better performance compared to conventional TEM horn antenna is introduced. An exponential tapered slot edge (TSE) structure is employed. Electromagnetic band gap structure as seven pair of loop or square shaped defected ground structure is added to the ground antenna plane. The proposed shape has the advantage of extending the low-end bandwidth limit due to improving the antenna matching especially at low frequency and reduced the electrical length of the antenna by 45% compared to the original antenna size.
---
paper_title: Antenna Theory: Analysis and Design

paper_content:

The most-up-to-date resource available on antenna theory and design. Expanded coverage of design procedures and equations makes meeting ABET design requirements easy and prepares readers for authentic situations in industry. New coverage of microstrip antennas exposes readers to information vital to a wide variety of practical applications.Computer programs at end of each chapter and the accompanying disk assist in problem solving, design projects and data plotting.-- Includes updated material on moment methods, radar cross section, mutual impedances, aperture and horn antennas, and antenna measurements.-- Outstanding 3-dimensional illustrations help readers visualize the entire antenna radiation pattern.
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paper_title: An Ultra-Wideband Quasi-Planar Antenna with Enhanced Gain

paper_content:

A new ultra-wideband antenna with enhanced and nearly constant gain is presented. This quasi-planar antenna is composed of a CPW-fed printed monopole and a short horn, both made out of a single substrate. The measurements demonstrate an almost ∞at peak gain of 5:5dBi § 0:7dB from 2.5GHz to 15GHz with the average gain difierence in XZ plane is roughly 2dB up to 8GHz, which further rise to 6dB at 10GHz. The antenna also has a nearly linear phase response in this band. Well tested performance both in frequency and time domains, along with broad azimuth pattern, results in minimal ringing of a radiated pulse. The new antenna is suitable for establishing good line of sight link for UWB transmission and other broadband applications.
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paper_title: Printed circular disc compact planar antenna for UWB applications

paper_content:

A printed planar antenna having a compact dimension of 27×23.5 mm2, fed by a microstrip line is proposed in this article. The proposed compact antenna consists of a circular disc radiator and partial ground plane with a rectangular slot on its' top edge. Experimental results show that the antenna has an ?10 dB impedance bandwidth ranges from 3.3 GHz to 20 GHz (193%) which almost covers the entire UWB band. A symmetric and stable radiation pattern with an average realized gain of 5.11 dBi makes the proposed antenna suitable for using in different UWB applications. Details of the proposed antenna design are presented and discussed.
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paper_title: Small size planar monopole antenna for high speed UWB applications

paper_content:

In modern wireless communication, UWB applications are becoming very popular because of reliable, secure and high speed data transmission over smaller distances. In these applications, it is very much essential to have small size printed antennas for transmitting and receiving of UWB signals. However, designing small size printed antennas with good performance is quite a challenging task. In this paper, we discuss performance characteristics of a simple and small size planar monopole antenna for UWB applications. Proposed UWB antenna is covering 10dB return loss frequencies ranging from 2.72GHz to 12.68GHz. This design is achieving a maximum gain of 5.24dBi at 9.25GHz and a maximum efficiency of 96.45% at 3.1GHz. This paper also discusses a reason of enhancement in gain and efficiency reduction at higher frequencies along with UWB antennas requirements. Proposed design dimensions are 30mm×30mm×1.6mm with FR-4 as a dielectric substrate. Because of small size and good performance, proposed UWB antenna can be used in many applications like 4G, wireless body area networks, spectrum sensing in cognitive radio, wireless telemetry, telemedicine and RF energy harvesting. Experimental result shows that, there is a good agreement between the simulated and measured antenna results.
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paper_title: Spanner shaped ultra wideband patch antenna

paper_content:

In recent years Cognitive radio and UWB technologies are emerging for efficient use of Spectrum for short range wireless communications. FCC also has released a wideband of 7.5 GHz (From 3.1GHz to 10.6GHz) as unlicensed to use it anytime anywhere. In cognitive radio for sensing purpose and in UWB transceiver, UWB antennas play a vital role. Since antenna dimensions are frequency dependent, designing an antenna for wideband is a challenging task. This paper discusses the step by step techniques to obtain ultra wide bandwidth (2.23GHz-11.4GHz) from narrowband patch antenna. Also it discusses the various antenna parameters of proposed antenna design, its simulated and experimental results.
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paper_title: Design of stair and slotted UWB antenna using stepped-feed with modified slotted ground plane

paper_content:

A modified design of an ultra-wide band antenna (UWB) using stepped feed, partial slotted ground, two level stairs with notches in patch and ground plane is simulated with band rejection feature. The enhanced frequency range (3.2 to 14.0 GHz) is covered by the proposed antenna with the overall dimensions of 25.0 (L) x 20.0 (W) x 1.60 (H) mm3. The voltage standing wave ratio (VSWR) is less than 2.0 for entire operating frequency range. The proposed antenna operating on 5.2/5.8 GHz wireless local area network (WLAN), 3.5/5.5 GHz WiMAX, X-band and partial range (12.0 to 14.0 GHz) of Ku-band finds its applications to secure military communication, radar, medical applications and home appliances.
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paper_title: Ground penetrating radar : theory and applications

paper_content:

Ground-penetrating radar (GPR) is a rapidly developing field that has seen tremendous progress over the past 15 years. The development of GPR spans aspects of geophysical science, technology, and a wide range of scientific and engineering applications. It is the breadth of applications that has made GPR such a valuable tool in the geophysical consulting and geotechnical engineering industries, has lead to its rapid development, and inspired new areas of research in academia. The topic of GPR has gone from not even being mentioned in geophysical texts ten years ago to being the focus of hundreds of research papers and special issues of journals dedicated to the topic. The explosion of primary literature devoted to GPR technology, theory and applications, has lead to a strong demand for an up-to-date synthesis and overview of this rapidly developing field. Because there are specifics in the utilization of GPR for different applications, a review of the current state of development of the applications along with the fundamental theory is required. This book will provide sufficient detail to allow both practitioners and newcomers to the area of GPR to use it as a handbook and primary research reference. *Review of GPR theory and applications by leaders in the field *Up-to-date information and references *Effective handbook and primary research reference for both experienced practitioners and newcomers
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paper_title: Design of a high-gain ultra-wideband slot antenna using frequency selective surface

paper_content:

A CPW-feed prototype slot antenna for ultra-wideband applications is proposed. The slot is made by etching on the ground plane, the union of two elliptical structures placed at right angles. The fractal shape antenna is excited by two stepped CPW feed. To enhance the gain, a compact ultra-wideband frequency selective surface (FSS) structure is designed and implemented. The measured impedance bandwidth of antenna with and without FSS is nearly same and equal to 9.0 GHz from 3.6 to 12.6 GHz. The measured peak gain varies from 3 to 5 dB without FSS and from 5 to 12.5 dB with FSS. Measured results are found in good agreement with the simulated results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1498–1502, 2014
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paper_title: High gain UWB antenna using compact multilayer FSS

paper_content:

A High gain antenna for UWB application is presented in this paper. The UWB characteristic of the antenna is achieved by asymmetric slot in the ground plane. A compact multilayer FSS is designed to achieve the UWB performance. A significant improvement in the peak gain value of antenna is obtained in low profile design, while maintaining the excellent impedance bandwidth of ultra wide band antenna. The average peak gain of antenna is increased from 4 dBi to 7 dBi as a result of FSS superstrate as a reflector. The average peak gain variation in the operating frequency range of antenna (2.5 GHz–14 GHz) is only 1–2 dB, which is a significant improvement over the gain variation of 3 to 4 dB for antenna alone system without using FSS. The most attractive feature of the design is that, it maintains compactness in the geometry along with all other features. This compact, optimized FSS reflector provide flexibility to the design to mount on any antenna situated closer to conducting bodies, example metal sheet, screen and cases.
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paper_title: Increasing the gain of a semicircular slot UWB antenna using an FSS reflector

paper_content:

In this paper we demonstrate the gain enhancement of a semicircular slot antenna using a multilayer frequency-selective surface (FSS). A theoretical analysis of the FSS with a UWB semicircular slot antenna is presented. The multilayer FSS provides an appropriate reflection phase to act as a reflector and is able to enhance the gain of the slot antenna. Simulations show a linear phase response from 3.5 GHz to 12 GHz that is sufficient for ultra wideband operation. A significant improvement of 3 to 4 dB gain over the whole frequency range is demonstrated. The composite antenna has a theoretical gain of 8 dBi and a very small maximum gain variation of ±1.5 dB over the 3.5 to 10 GHz frequency range. Its compact configuration provides flexibility for mounting the reflector close to the slot antenna and makes it more suitable for modern UWB devices.
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paper_title: Quad ridged UWB TEM horn antenna for GPR applications

paper_content:

A compact quad-ridged horn antenna (QRH) for the deep ground penetrating radar water detection applications is designed operate in frequency range of 50MHz to 500MHz. Within this contribution the design and simulation of such an antenna is considered for water level detection in Egyptian dessert aquifers. Among the varying horn design parameters, the linear and exponentially tapered walls are studied as well as variations of the curvature of the dielectric waveguide between the two ridges enhancing the matching conditions hence, reducing size and increasing the antenna operational bandwidth. The design goal is to achieve broad bandwidth antenna with maintaining compact dimensions. Two modifications have been introduced on the conventional triangular TEM horn antenna. First multifunction tapering of the horn plates with curvature ending, second inserting perturbing two different ridges between the aperture planes and filling the space between the ridges with high dielectric constant material, in order to lower the operating frequency without increasing the size of the original setup. Replacing the two ridges with four ones, each pair is perpendicular to the other, reduces more the antenna size and improves more its matching. The antenna dimensions are 145 × 102 × 124 cm ::: 3 ::: that resembles improvement in size as compared with similar commercial GPR horn antennas as Satimo Horn model SH 68 with dimensions 2983×1615×2505 cm ::: 3 ::: .
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paper_title: An ultra-wideband absorber backed planar slot antenna

paper_content:

Planar antenna designs have many advantages such as low-profile, light-weight, and ease of fabrication and integration. Low-cost is often desired but this depends on the chosen substrate. The substrate can also dominate the ruggedness of the antenna, such as the use of ceramics which can be brittle. Here, a planar slot antenna implemented on ceramic substrate with coplanar waveguide feed is considered. With absorber loading the design provides 50 Ω input impedance over the frequency range 0.3–3 GHz so it is considered ultra-wideband. This paper summarizes a numerical investigation using both frequency and time-domain solvers. The results serve to guide the future analysis of broadband antennas with lossy dielectric loading for ground penetrating radars. The evaluation of radar performance requires further simulation and model validation based on antenna measurements.
---
paper_title: A Novel Compact Double Exponentially Tapered Slot Antenna (DETSA) for GPR Applications

paper_content:

A novel compact double exponentially tapered slot antenna (DETSA) for GPR applications is presented. To extend the antenna's impedance bandwidth, the antenna arms are rolled back and lengthened, and lumped resistors are used near the ends of the rolled arms. An improved coplanar waveguide (CPW) to coupled stripline (CPS) transition for feeding is also investigated. The measured transmission loss of two back-to-back CPW-to-CPS transitions is less than 2.6 dB in the frequency band of 200 MHz-6 GHz, which agrees well with the simulated result. The measured S11 of the antenna in frequency domain is less than -10 dB in the band of 220 MHz-6 GHz, and it is also verified that the resistors mainly have influence on the antenna's S11 below 1 GHz. The measured reflected pulses show that there are only two reflecting points, and the reflection is weak. The simulated and measured antenna gains at boresight show little variations with loading resistors of different values, and this means that the resistive loadings do not affect the gain characteristics of the antenna. The antenna's transmission re- sponse in time domain is also tested, and its application in GPR detection of a buried target is validated by experiments.
---
paper_title: Design of a high-gain ultra-wideband slot antenna using frequency selective surface

paper_content:

A CPW-feed prototype slot antenna for ultra-wideband applications is proposed. The slot is made by etching on the ground plane, the union of two elliptical structures placed at right angles. The fractal shape antenna is excited by two stepped CPW feed. To enhance the gain, a compact ultra-wideband frequency selective surface (FSS) structure is designed and implemented. The measured impedance bandwidth of antenna with and without FSS is nearly same and equal to 9.0 GHz from 3.6 to 12.6 GHz. The measured peak gain varies from 3 to 5 dB without FSS and from 5 to 12.5 dB with FSS. Measured results are found in good agreement with the simulated results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1498–1502, 2014
---
paper_title: A Differential-Fed Magneto-Electric Dipole Antenna for UWB Applications

paper_content:

A new magneto-electric dipole antenna with a unidirectional radiation pattern is proposed. A novel differential feeding structure is designed to provide an ultra-wideband impedance matching. A stable gain of 8.25±1.05 dBi is realized by introducing two slots in the magneto-electric dipole and using a rectangular box-shaped reflector, instead of a planar reflector. The antenna can achieve an impedance bandwidth of 114% for SWR ≤ 2 from 2.95 to 10.73 GHz. Radiation patterns with low cross polarization, low back radiation, fixing broadside direction mainbeam and symmetrical E- and H -plane patterns are obtained over the operating frequency range. Moreover, the correlation factor between the transmitting antenna input signal and the receiving antenna output signal is calculated for evaluating the time-domain characteristic. The proposed antenna, which is small in size, can be constructed easily by using PCB fabrication technique.
---
paper_title: Multioctave Frequency Selective Surface Reflector for Ultrawideband Antennas

paper_content:

In this letter, we demonstrate the gain enhancement of an ultrawideband (UWB) antenna, achieved using an appropriately designed multioctave dual-layer frequency selective surface (FSS) reflector. The proposed novel FSS reflects effectively in phase over a bandwidth of about 120%. Hence, significant enhancement in antenna gain has been achieved with a low-profile configuration without compromising the impedance bandwidth of the UWB antenna. The proposed FSS reflector has a low transmission coefficient and linearly decreasing phase over an ultra-wide frequency band, which is the key requirement for providing an effectively in-phase reflection at the antenna plane. The composite structure is compact, with a total height of λ/4, where λ is the free-space wavelength at the lowest operating frequency of 3 GHz. Experimental results show an impedance bandwidth of 122%. The antenna gain is maintained around 7.5 dBi from 3 to 7 GHz. Between 7-14 GHz, the antenna is more directive with a gain of about 9 dBi with ±0.5 dB variation. Experimental measurements con firm the predicted wideband antenna performance and gain enhancement due to the FSS reflector.
---
paper_title: Design and simulation of compact UWB Bow-tie antenna with reduced end-fire reflections for GPR applications

paper_content:

The efficiency of the ground penetrating radar (GPR) system significantly depends on the antenna performance as signal has to propagate through lossy and inhomogeneous media. In this research work a resistively loaded compact Bow-tie antenna which can operate through a wide bandwidth of 4.1 GHz is proposed. The sharp corners of the slot antenna are rounded so as to minimize the end-fire reflections. The proposed antenna employs a resistive loading technique through a thin sheet of graphite to attain the ultra-wide bandwidth. The simulated results obtained from CST Microwave Studio v14 and HFSS v14 show a good amount of agreement for the antenna performance parameters. The proposed antenna has potential to apply for the GPR applications as it provides improved radiation efficiency, enhanced bandwidth, gain, directivity and reduced end-fire reflections.
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paper_title: Design of Transverse Electromagnetic Horn for Concrete Penetrating Ultrawideband Radar

paper_content:

We propose a design for the specific class of trans- verse electromagnetic (TEM) horn that can effectively radiate the electromagnetic signals into soil or concrete. The designed horn antenna has the same aperture height and width, resulting in a square-shaped horn aperture. A design guideline for the horn that considers return loss and radiation performance is described in this paper. The proposed TEM horn is constructed and measured to validate the design. The constructed horn has a maximum dimension (including the balun) of 42.9 × 26.8 × 20 cm. Simulated and measured results suggest that the proposed horn is more effective in radiating electromagnetic energy into concrete, compared with existing TEM horn designs. For free space radiation, measured operating bandwidth of the horn is 0.75-12.0 GHz, with a gain of 3-13 dBi. When radiated into a concrete block, measured operating bandwidth of the horn is 1.0-12.0 GHz.
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paper_title: Design of a low cost cavity backed wideband bow-tie antenna for ground penetrating radar systems

paper_content:

The ground penetrating radar (GPR) designs demand antennas with ultra wide bandwidths (UWB). Thus the conventional antennas such as dipoles cannot be used effectively. The GPR antennas are expensive. In this paper, the feasibility of building a low cost ultra-wide band bow-tie antenna for GPR using widely available low cost materials such as FR-4 PCB substrates, low cost TV baluns and scrap iron is explored. The objective was to develop the antenna to radiate in the range from 200 MHz to 600 MHz whilst restricting the antenna lobes to the direction of the ground. A cavity backed design is considered to obtain these requirements. The antenna was modeled using Ansoft HFSS (presently Ansys HFSS) software package which is widely used in current industrial domain. The simulations were carried out for different antenna configurations by changing its parameters according to linear programming techniques. Further, electromagnetic interferences (EMI) have been successfully reduced by integrating a metal cavity which acts as a reflector to the antenna. Parameters related to the cavity were tweaked in order to obtain the optimum frequency response. Considering the simulation results the most satisfactory antenna configuration was obtained and implemented.
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paper_title: An Improved Design of Planar Elliptical Dipole Antenna for UWB Applications

paper_content:

In this letter, an enhanced planar elliptical dipole antenna design for ultrawideband (UWB) communication and impulse radar systems is presented. The printed-circuit-elliptical (PCE) antenna has been investigated to be an effective radiator for UWB applications. To enhance gain and return loss bandwidth of the antenna, elliptical slots are used on the dipole arms. The gain performance of the antenna has been increased by means of elliptical slots in the frequency range from 2.7 to 11 GHz. The standing wave ratio is less than 2 (SWR < 2) along 94.4% of operation bandwidth from 1.1 to 11 GHz. The radiation pattern in E- and H-plane for certain frequencies, the return loss, and the gain performance are presented with the experimental and simulation results. Moreover, the time domain analysis of the antenna is presented. The antenna introduces low-level ringing and pulse distortion. Consequently, the antenna is very useful for impulse and UWB communication systems.
---
paper_title: Novel shapes of Vivaldi antenna for ground pentrating radar (GPR)

paper_content:

Novel planar Vivaldi antenna with better performance compared to conventional TEM horn antenna is introduced. An exponential tapered slot edge (TSE) structure is employed. Electromagnetic band gap structure as seven pair of loop or square shaped defected ground structure is added to the ground antenna plane. The proposed shape has the advantage of extending the low-end bandwidth limit due to improving the antenna matching especially at low frequency and reduced the electrical length of the antenna by 45% compared to the original antenna size.
---
paper_title: UWB antennas for ground penetrating radar application

paper_content:

Presented paper describes results of comparison study on antennas for ground penetrating radar (GPR, undersurface radar) operating in frequency band from 500 MHz to 3 GHz. Typical representatives of elementary antennas, planar monopoles, dipole antennas, tapered slot antennas, TEM horns and frequency independent antennas are firstly optimized for the operation band in CST design environment. Then structures are described and compared from the impedance, radiation and time characteristic point of view to enable a simple choice of suitable structures for manufacture. Selected antennas are prepared for the manufacture and comparison with their models.
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paper_title: in situ measurement of pavement thickness and dielectric permittivity by GPR using an antenna array

paper_content:

Abstract We present a ground penetrating radar (GPR) system, which uses an antenna array for in situ measurements of the thickness and dielectric permittivity of an asphalt pavement layer. We calibrated the antenna array by considering the antenna phase center and the antenna offset. The results of the laboratory measurements demonstrate that the proposed calibration method can greatly improve the accuracy of the velocity and thickness estimations when compared with the conventional method. A field measurement conducted on a highway pavement shows that the error of the thickness estimation of the asphalt layer is less than 6 mm (10%).
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paper_title: Ultra Wide Band horn antenna design for Ground Penetrating Radar: A feeder practice

paper_content:

Ultra-Wide Band (UWB) technology in Ground Penetrating Radar (GPR) imaging has been an interested research topic for the last couple of decades. Although there have been a lot of work and research conducted on this subject, there c still interested research matters that has to be studied. UWB directional antennas are one of the critical components for UWB-GPR applications. The parameters of the antennas that are used within the system affect the performance of the application. The horn antenna; for example, can give the focusing ability needed in some applications thanks to its high directivity feature. Although there are many parameters that affect the design of a Horn antenna, aperture size and the feeder type are commonly used parameters to obtain wider frequency operation. In this study, the effect of different feeding structures on frequency bandwidth for a fixed waveguide dimensions are investigated and the results are shared. For this purpose, various feeding structures that are straight wire feeder, spherical feeder, cylindrical feeder and conical feeder are examined and the simulated and the measured bandwidth results are presented. Furthermore, we propose a new feeder type that provides better simulation results in terms of bandwidth is introduced. With this new structure, the horn antenna is optimized using an antenna simulation software; CST-Microwave Studio and the corresponding produced antenna is measured to complete the design.
---
paper_title: A Novel Compact Double Exponentially Tapered Slot Antenna (DETSA) for GPR Applications

paper_content:

A novel compact double exponentially tapered slot antenna (DETSA) for GPR applications is presented. To extend the antenna's impedance bandwidth, the antenna arms are rolled back and lengthened, and lumped resistors are used near the ends of the rolled arms. An improved coplanar waveguide (CPW) to coupled stripline (CPS) transition for feeding is also investigated. The measured transmission loss of two back-to-back CPW-to-CPS transitions is less than 2.6 dB in the frequency band of 200 MHz-6 GHz, which agrees well with the simulated result. The measured S11 of the antenna in frequency domain is less than -10 dB in the band of 220 MHz-6 GHz, and it is also verified that the resistors mainly have influence on the antenna's S11 below 1 GHz. The measured reflected pulses show that there are only two reflecting points, and the reflection is weak. The simulated and measured antenna gains at boresight show little variations with loading resistors of different values, and this means that the resistive loadings do not affect the gain characteristics of the antenna. The antenna's transmission re- sponse in time domain is also tested, and its application in GPR detection of a buried target is validated by experiments.
---
paper_title: Printed circular disc compact planar antenna for UWB applications

paper_content:

A printed planar antenna having a compact dimension of 27×23.5 mm2, fed by a microstrip line is proposed in this article. The proposed compact antenna consists of a circular disc radiator and partial ground plane with a rectangular slot on its' top edge. Experimental results show that the antenna has an ?10 dB impedance bandwidth ranges from 3.3 GHz to 20 GHz (193%) which almost covers the entire UWB band. A symmetric and stable radiation pattern with an average realized gain of 5.11 dBi makes the proposed antenna suitable for using in different UWB applications. Details of the proposed antenna design are presented and discussed.
---
paper_title: Ultrawideband Phased Array Antenna Technology for Sensing and Communications Systems

paper_content:

Ultrawideband phased array antennas are an enabling technology for many ground-based and airborne communications and radar systems. This book surveys electromagnetic theory and phased array antenna theory and provides examples of ultrawideband phased array antenna technology. It describes some of the research on ultrawideband phased arrays undertaken by the authors and their colleagues at MIT Lincoln Laboratory over the last ten years. The book focuses on experimental prototype ultrawideband phased array technology developed at Lincoln Laboratory for applications in the VHF and UHF bands from approximately 100 MHz to 1 GHz, and addresses dipole, monopole, loop, and other antenna array elements. It offers examples of antennas for both airborne and ground vehicle applications. Most of the examples are developed in the context of rapid prototyping for quick assessment of communications and radar systems feasibility, with measurements and numerical electromagnetic simulation results provided for many prototype examples. The book is intended primarily for practicing antenna engineers, radar engineers, and communications engineers, and for graduate students and researchers in electrical engineering. Readers need no prior knowledge of ultrawideband antennas, although some background in electromagnetic theory, antennas, radar, and communications would be helpful.
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paper_title: Frontiers in Antennas: Next Generation Design & Engineering

paper_content:

Chapter 1 Ultra-Wideband Antenna Arrays Chapter 2 Smart Antennas Chapter 3 Vivaldi Antenna Arrays Chapter 4 Artificial Magnetic Conductors/High Impedance Surfaces Chapter 5 Metamaterial Antennas Chapter 6 Biological Antenna Design Methods Chapter 7 Reconfigurable Antennas Chapter 8 Antennas in Medicine: Ingestible Capsule Antennas Chapter 9 Leaky-Wave Antennas Chapter 10 Plasma Antennas Chapter 11 Numerical Methods in Antenna Modeling
---

Title: Ultra-Wideband Antenna Design for GPR Applications: A Review

Section 1: INTRODUCTION
Description 1: Write about the background of ultra-wideband (UWB) systems, their applications, and the significance of UWB antennas in Ground Penetrating Radar (GPR) technology.

Section 2: ANTENNA DESIGN FOR GPR
Description 2: Discuss various types of UWB antenna designs for GPR applications, focusing on the lower and higher frequency bands to balance penetration depth and resolution imaging.

Section 3: Bow-tie Antenna
Description 3: Provide details on the design variations, performance characteristics, and advantages of Bow-tie antennas in GPR systems.

Section 4: Vivaldi Antenna
Description 4: Elaborate on the different designs and enhancements of Vivaldi antennas for achieving greater bandwidth and improved performance in GPR applications.

Section 5: Horn Antenna
Description 5: Describe the structure, modifications, and benefits of Horn antennas, emphasizing their ability to penetrate deeper into the ground for GPR systems.

Section 6: Planar Antenna
Description 6: Discuss the characteristics, structural designs, and implementations of planar antennas for UWB GPR applications.

Section 7: Tapered Slot Antenna
Description 7: Explain the design principles, gains, and bandwidth improvements of tapered slot antennas, highlighting their suitability for GPR applications.

Section 8: Dipole, Cone, and Spiral Antenna
Description 8: Review the construction and performance of dipole, cone, and spiral antennas and their potential for use in GPR systems.

Section 9: RESULTS AND DISCUSSIONS
Description 9: Present the results of the studied antenna designs, summarizing their performance in terms of operating frequency, bandwidth, and gain for GPR applications.

Section 10: CONCLUSION
Description 10: Summarize the findings of the review, highlighting the best antenna designs for GPR applications and suggesting directions for future research.