Microwaves are radio waves radio waves with wave lengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz.

This broad definition includes both UHF and EHF (millimeter waves), and various sources use different boundaries. In all cases, microwave includes the entire SHF 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). The prefix “micro-” in “microwave” is not meant to suggest a wavelength in the micrometer range. It indicates that microwaves are “small” compared to waves used in typical radio broadcasting, in that they have shorter wavelengths. 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.

Microwave technology has wide range of application areas. Traditionally it has been used for telecommunication/communication purposes but it is also used for different kinds of sensing and imaging applications. Heating of different substance such as food is another area. The application areas are many can be categories in different ways.

• Telecom
• Point-to-point communication, Satellite, Cellular access technologies
• Space
• Sensing/Spectroscopy, Communication, Radio astronomy
• MedTech
• Diagnostics, imaging, and treatment applications.
• Defense
• Radar, Communication
• Security
• Car avoidance radar, Traffic surveillance, Air traffic security “cameras”
• Navigation, Positioning & Measurement
• GPS
• Food
• Heating & detection of foreign bodies in food New and novel application areas are constantly being added.