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The antennas contained in mobile phones, including smartphones, emit radiofrequency (RF) radiation (non-ionizing "radio waves" such as microwaves); the parts of the head or body nearest to the antenna can absorb this energy and convert it to heat or to synchronised molecular vibrations (the term 'heat', properly applies only to disordered molecular motion).
The depth of penetration depends on the frequency of the microwaves and the tissue type. The Active Denial System ("pain ray") is a less-lethal directed energy weapon that employs a microwave beam at 95 GHz; a two-second burst of the 95 GHz focused beam heats the skin to a temperature of 130 °F (54 °C) at a depth of 1/64th of an inch (0.4 mm) and is claimed to cause skin pain without lasting ...
The mechanism is the same as that used in a microwave oven. [6] The heating effect varies with the power and the frequency of the electromagnetic energy, as well as the inverse square of distance to the source. The eyes and testes are particularly susceptible to radio frequency heating due to the paucity of blood flow in these areas that could ...
Plus, the microwaves emitted by a traditional household Wi-Fi router antenna are almost “identical in frequency to the microwaves generated in a microwave oven,” says Christopher S. Baird, an ...
IR wavelengths are longer than that of visible light, but shorter than that of terahertz radiation microwaves. Bright sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet radiation. [7]
This broad definition includes both UHF and EHF (millimetre waves), but various sources use different other limits. [4] In all cases, microwaves include the entire super high frequency band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often putting the lower boundary at 1 GHz (30 cm), and the upper around 100 GHz (3 mm).
A microwave oven passes microwave radiation at a frequency near 2.45 GHz (12 cm) through food, causing dielectric heating primarily by absorption of the energy in water. Microwave ovens became common kitchen appliances in Western countries in the late 1970s, following the development of less expensive cavity magnetrons. Water in the liquid ...
A microwave oven is an example of this principle put to controlled, safe use. Radio-frequency (RF) energy is non-ionizing electromagnetic radiation – its effects on tissue are through heating. Electronic components are affected via rectification of the RF and a corresponding shift in the bias points of the components in the field.