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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.
A Winegard 68 element VHF/UHF aerial antenna. This common multi-band antenna type uses a UHF Yagi at the front and a VHF log-periodic at the back coupled together. When a higher-gain antenna is needed to achieve adequate reception in suburban or fringe reception areas, an outdoor directional antenna is usually used.
The driven elements between the UHF and VHF are then coupled and often matched for a 75 Ω coaxial downlead to the receiver. When a "driven element" is referred to in an antenna array, it is often assumed that other elements are not driven (i.e. passive radiator) and that the array is tightly coupled (spacing far below a wavelength).
Stubs are commonly used in antenna impedance matching circuits, frequency selective filters, and resonant circuits for UHF electronic oscillators and RF amplifiers. Stubs can be constructed with any type of transmission line : parallel conductor line (where they are called Lecher lines ), coaxial cable , stripline , waveguide , and dielectric ...
This mast has two UHF antennas for receiving signals from different directions. The lower antenna is a bowtie array. The upper antenna is a Yagi design. UHF television broadcasting is the use of ultra high frequency (UHF) radio for over-the-air transmission of television signals. UHF frequencies are used for both analog and digital television ...
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.
A desirable null exists if the transmit antenna is located exactly below the receive antenna beyond a minimum distance. Almost the same isolation as a low-grade duplexer (about −60 decibels) can be accomplished by installing the transmit antenna below, and along the centerline of, the receive antenna.
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 ...