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The AT&T receiving Beverage antenna (left) and radio receiver (right) at Houlton, Maine, used for transatlantic telephone calls, from a 1920s magazine. The Beverage antenna or "wave antenna" is a long-wire receiving antenna mainly used in the low frequency and medium frequency radio bands, invented by Harold H. Beverage in 1921. [1]
Due to their omnidirectional radiation pattern, vertical monopole antennas are commonly used in terrestrial radio communication systems in which the direction to the transmitter or receiver is unknown or constantly changing, [7] such as broadcasting, mobile two-way radios, and wireless devices like cellphones and Wi-fi networks, [8] [4] because they radiate equal radio power in all horizontal ...
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A mast radiator or mast antenna is a radio tower or mast in which the whole structure is an antenna. Mast antennas are the transmitting antennas typical for long or medium wave broadcasting. Structurally, the only difference is that some mast radiators require the mast base to be insulated from the ground.
The RP-23 Sapfir (NATO codename: High Lark) was a Soviet look-down/shoot-down radar system. It was developed by Phazotron specifically for the Soviet Air Forces (VVS) new MiG-23 fighter aircraft and used in conjunction with the Vympel R-23 (NATO codename: AA-7 Apex) beyond visual range air-to-air missile.
The commercially available B&W AC3-30 and B&W DS1.8-30 antennas [6] vary from the above to cover 3–30 MHz using a 90 foot length with an 18 inch spacing of the wires. The balun is a 16:1 ratio, thereby transforming the 50 Ω (ohm) coax to an 800 Ω feed at the antenna.
Antenna diversity is especially effective at mitigating these multipath situations. This is because multiple antennas offer a receiver several observations of the same signal. Each antenna will experience a different interference environment. Thus, if one antenna is experiencing a deep fade, it is likely that another has a sufficient signal ...
The AN/APG-68 is an improvement to the AN/APG-66 used on the F-16A/B. [5] The AN/APG-68(V)8 and earlier radar system consists of the following line-replaceable units: Antenna; Dual Mode Transmitter (DMT) Modular Low-power radio frequency (MLPRF) Programmable signal processor (PSP)