Microwave Radiation

Abstract

In the upper boundary of the frequency scale of electromagnetic radiation are the radioelectric signals. The frequency range extending from 300 GHz (3 × 10¹¹ Hz or wavelength of 1 mm) down to 300 MHz (3 × 10⁸ Hz or wavelength of 100 cm), which characterizes signals having between 300 million and 300 billion periods per second (the period of a signal is defined as the inverse of the frequency, and is located between 3 ns and 3 ps), is generally known as microwave radiation. These limits are to some extent arbitrary but they permit position of the microwave domain between infrared rays, at the higher end of the frequency range, and radio and TV waves at the lower end. (The prefix micro may lead to the expectation of wavelengths in the micrometer range and not, as is actually the case, in the millimeter to meter range). Even weak chemical bonds, such as hydrogen bonds, have energies that are several orders of magnitude greater than the energy of microwave photons. Not until the frequency of a radiation approaches, or exceeds, 10¹⁶ Hz do photon energies become comparable to the binding energy of electrons to atoms. It seems quite resonable, therefore, that microwave photons cannot disrupt the electronic structure of atoms, nor can they disrupt chemical bonds.