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The IEEE defines the UHF radar band as frequencies between 300 MHz and 1 GHz. [3] Two other IEEE radar bands overlap the ITU UHF band: the L band between 1 and 2 GHz and the S band between 2 and 4 GHz. UHF television antenna on a residence. This type of antenna, called a Yagi–Uda antenna, is widely used at UHF frequencies.
Radial stubs are a planar component that consists of a sector of a circle rather than a constant-width line. They are used with planar transmission lines when a low impedance stub is required. Low characteristic impedance lines require a wide line. With a wide line, the junction of the stub with the main line is not at a well-defined point.
The antenna feed system or antenna feed is the cable or conductor, and other associated equipment, which connects the transmitter or receiver with the antenna and makes the two devices compatible. [ 1 ] [ 2 ] In a radio transmitter, the transmitter generates an alternating current of radio frequency , and the feed system feeds the current to ...
Corner reflector UHF TV antenna from 1954 with bowtie dipole driven element. A corner reflector antenna is a type of directional antenna used at VHF and UHF frequencies. [1] [2] It was invented by John D. Kraus in 1938. [3] [4] It consists of a dipole driven element mounted in front of two flat rectangular reflecting screens joined at an angle ...
Antenna diversity, also known as space diversity or spatial diversity, is any one of several wireless diversity schemes that uses two or more antennas to improve the quality and reliability of a wireless link. Often, especially in urban and indoor environments, there is no clear line-of-sight (LOS) between transmitter and receiver. Instead the ...
Slotted array UHF television broadcasting antenna. As shown by H. G. Booker in 1946, from Babinet's principle in optics a slot in a metal plate or waveguide has the same radiation pattern as a driven rod antenna whose rod is the same shape as the slot, with the exception that the electric field and magnetic field directions are interchanged; the antenna is a magnetic dipole instead of an ...
This reflective array television antenna consists of eight "bowtie" dipole driven elements mounted in front of a wire screen reflector. The X-shaped dipoles give it a wide bandwidth to cover both the VHF (174–216 MHz) and UHF (470–700 MHz) bands. It has a gain of 5 dB VHF and 12 dB UHF and an 18 dB front-to-back ratio.
The J-pole antenna is an end-fed omnidirectional half-wave antenna that is matched to the feedline by a shorted quarter-wave parallel transmission line stub. [5] [1] [6] For a transmitting antenna to operate efficiently, absorbing all the power provided by its feedline, the antenna must be impedance matched to the line; it must have a resistance equal to the feedline's characteristic impedance.