Energy that moves through space and matter in the form of electromagnetic waves.
Comment: In physics electromagnetic energy is considered to be in the form of both electromagnetic waves and photons. Photons are perceived as “energy particles” which generally are smaller than a grain of sand. Grains of sand are true particles, but lower frequencies, such as cellular phone frequencies which have wavelengths approximately between the size of a baseball up to the size of a soccer ball, are not really particles, per se.
When it comes to the lower frequencies of radio frequency and microwave frequency energy, photon theory has not been shown to be useful. The wave form of energy is far more evident in these frequencies. This is evidenced throughout wireless technology engineering where you will never find engineers speaking of the wireless energy in terms of photons. Only when the frequency of the energy becomes so high that the wavelength of the energy approaches that of light does photon theory become useful. Keep in mind that both wave theory and particle (photon) theory are both theories, not proven facts.
Electromagnetic frequencies that are used in cellular phone and 4G-LTE networks, Wi-Fi networks, cordless phones, smart grid meters and most consumer wireless devices.
The frequency range used in consumer technologies is between around 800 megahertz and 6 gigahertz. The broader definition of microwaves is electromagnetic radiation between radio waves and infrared waves in the electromagnetic spectrum, having frequencies between 300 megahertz and 300 gigahertz and wavelengths between 1 meter and 1 millimeter.
The amount of power in electromagnetic radiation per unit of area. Typically centimeters squared (cm2) or meters squared (m2). The power level is usually indicated in micro-watts (uW) or mili-watts (mW) in the USA.