Microwave electro-mageetic radiation.
The list of lowest-radiation cellphones includes the LG KG800 and the Motorola Razr V3x, which put out 0.135 W/kg and 0.14 W/kg, respectively. To see all the lowest radiation phones, click here. If you don’t see your phone on the list, the site includes lists of cellphones by brand name. The charts focus on the specific absorption rate, or SAR, of a cellphone, which is a way of measuring the quantity of radio frequency energy that is absorbed by the body, according to CNET. For a phone to pass F.C.C. certification, that phone’s maximum SAR level must be less than 1.6 W/kg (watts per kilogram). 7. Cordless home phones give off radiation. Just as a cell phone communicates with a tower, a cordless home phone handset emits signals to the base station in your home. Like a cell phone, the cordless phone handset emits peak levels of radiation during a call. When a phone is on and not in use, it send outs an intermittent signal to connect with nearby cell phone towers. The phone’s “check in” communication with the tower is significantly lower than the level of radiation used for actual conversation, but it never falls to zero. A display of bars on a mobile phone screen. A mobile phone signal (also known as reception and service) is the signal strength (measured in dBm) received by a mobile phone from a cellular network (on the downlink). Depending on various factors, such as proximity to a tower, any obstructions such as buildings or trees, etc., this signal strength will vary. Generally, a strong mobile phone signal is more likely in an urban area, though these areas can also have some dead zones where no reception can be obtained. Cell phones have a low-power transmitter in them. Most car phones have a transmitter of 3 watts. A hand held call phone operates on about 0.75 to 1 watt of power. The radio waves that send the encoded signal are made up of electromagnetic radiation propagated the antenna. The charts focus on the specific absorption rate, or SAR, of a cellphone, which is a way of measuring the quantity of radio frequency energy that is absorbed by the body, according to CNET. For a phone to pass F.C.C. certification, that phone’s maximum SAR level must be less than 1.6 W/kg (watts per kilogram). Bars on a cell phone usually are not an accurate measure of cell phone strength. They are like a gas gage, they give you an idea of what the signal is, not the actual strength. You can have two different brands of cell phones next to each other using the same carrier and they might show different bars. Some carriers have bragged they have more bars than anyone else. The dB number is a measurement in relation to a milliwatt. Usually these kind of numbers are measured with RF meters that cost thousands of dollars so the accuracy might be off a bit with a $200 cell phone, but it should be close enough. Answer: No. Mobile phones do not give off sub-atomic (ionizing)  radiation.    Answer: Yes. Mobile phones emit microwave (millimeter to  centimeter range) electro-mag … netic radiation, mostly at frequencies  from 800 to 1800 MHz (1.8 GHz). This is below infrared.  Yes – cell phones and cordless phones use radiofrequency radiation (RF) to send signals. RF is different from other types of radiation (like x-rays) that we know can be harmful. We don’t know for sure if RF radiation from cell phones can cause health problems years later.  At 10 times the distance between the cell phone and your head, the signal strength is 100 times less, and at 100 times the distance, it would be 10,000 times less.  Keep conversations short. The less you talk on your cell phone, the less exposure to radiation you will have. Use the speaker phone function of the cell phone. For the same reason you'd use a headset, using a speaker phone is another good option. It keeps the cell phone away from your body, and you don't have to worry about using a headset. One way the operator can do this is to observe the signal strength that different towers observe from a particular subscriber's mobile phone, and then calculate where that phone must be located in order to account for these observations. Mobile phones have become ubiquitous and basic communications tools—now used not only for phone calls, but also for accessing the Internet, sending text messages, and documenting the world. Unfortunately, mobile phones were not designed for privacy and security.
http://well.blogs.nytimes.com/2008/06/11/how-much-radiation-does-your-phone-emit/comment-page-10/ http://www.ewg.org/research/cellphoneradiation/faq https://en.wikipedia.org/wiki/Mobile_phone_signal http://well.blogs.nytimes.com/2008/06/11/how-much-radiation-does-your-phone-emit/comment-page-10/ http://powerfulsignal.com/cell-signal-strength.aspx http://www.answers.com/Q/What_kind_of_signal_does_a_mobile_phone_give_off http://www.cdc.gov/nceh/radiation/cell_phones._FAQ.html http://www.cnet.com/news/cell-phone-radiation-a-self-defense-guide-faq/ https://ssd.eff.org/en/module/problem-mobile-phones
what signal does a mobile phone give off