Consumer Electronics

MICROWAVES

A microwave is a signal that has a wavelength of one foot (30.5 cm) or less. This converts to a frequency of 984 MHz, so all frequencies above 1000 MHz (1 GHz) are considered microwaves. The frequencies immediately below this border are considered ultra-high frequencies. The upper end of the microwave range contains the light frequencies, about 10¹⁵ Hz. However, because electronic transmission is so closely geared to half-wavelength devices, the practical upper limit is about 300 GHz, where one wavelength is about 0.04 inch (0.1 cm). Smaller devices are being made, but their power handling abilities are also micro.

Normally microwaves spread outwards as they travel through the atmosphere and disappear without effect. The microwave ...