Microwave


Microwaves are electromagnetic waves with wavelengths longer than those of terahertz (THz) frequencies, but relatively short for radio waves. Microwaves have wavelengths approximately in the range of 30&nbsp;cm (frequency = 1&nbsp;GHz) to 1&nbsp;mm (300&nbsp;GHz). This range of wavelengths has led many to question the naming convention used for microwaves as the name suggests a micrometer wavelength. However, the boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high-frequency radio waves are fairly arbitrary and are used variously between different fields of study. The same equations of electromagnetic theory apply at all frequencies. Apparatus and techniques may be described as "microwave" when the wavelengths of signals are roughly similar as the dimensions of the equipment, so that lumped-element circuit theory is no longer accurate. The term microwave generally refers to "alternating current signals with frequencies between 300 MHz (3×10<sup>8</sup> Hz) and 300 GHz (3×10<sup>11</sup> Hz)."[1]