Antennas are used for a huge range of applications, from mobile phones and “smart” WiFi-connected appliances to GPS and systems that track aircraft and help pilots land safely. Over the years, several distinct types of antennas have come into common use, with designs, frequencies and operating power levels that depend …

Radar, electromagnetic sensor used for detecting, locating, tracking, and recognizing objects of various kinds at considerable distances. It operates by transmitting electromagnetic energy toward objects, commonly referred to as targets, and observing the echoes returned from them.  Energy is emitted in various frequencies and wavelengths from large wavelength radio waves to …