WikiVisually
The entire wiki reimagined as a visual magazine with video discovery · Watch your interests come alive
WikiVisually
The entire wiki reimagined as a visual magazine with video discovery · Watch your interests come alive
Nature The World Movies USA Top Art Fine & Rare History Ivy & Inquiry
Reflective array antenna
Videos
In telecommunications and radar, a reflective array antenna is a class of directive antennas in which multiple driven elements are mounted in front of a flat surface designed to reflect the radio wave
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 example shown is horizontally polarised.
This reflective array television antenna consists of eight "bowtie" dipole driven elements mounted in front of a wire screen reflector. The X-shaped d
Reflective array 'billboard' antenna of the SCR-270 radar, an early US Army radar system. It consists of 32 horizontal half wave dipoles mounted in fr
Reflective array 'billboard' antenna of the SCR-270 radar, an early US Army radar system. It consists of 32 horizontal half wave dipoles mounted in front of a 17 m (55 ft) high screen reflector. With an operating frequency of 106 MHz and a wavelength of 3 m (10 ft) this large antenna was required to generate a sufficiently narrow beamwidth to locate enemy aircraft.
A modern form of reflective array is the "bow tie" UHF television antenna. This example has two dipole driven elements in front of a grill reflector.
A modern form of reflective array is the "bow tie" UHF television antenna. This example has two dipole driven elements in front of a grill reflector. The "bow-tie" dipoles, consisting of two V-shaped elements, have a larger bandwidth than ordinary dipoles, allowing the antenna to cover the wide UHF television band. This example is installed for reception of vertically polarized TV transmissions.
Enormous reflective array antenna of the Duga or "Steel Yard" over-the-horizon (OTH) radar system, Chernobyl, Ukraine, part of the Soviet early-warnin
Enormous reflective array antenna of the Duga or "Steel Yard" over-the-horizon (OTH) radar system, Chernobyl, Ukraine, part of the Soviet early-warning network. It transmits at frequencies between 7 and 19 MHz. The pairs of cylindrical cages at right are the half wave dipole driven elements. Behind them is a reflector screen of horizontal wires, just visible in center.
Television antenna
Videos
A television antenna, also called a television aerial, is an antenna specifically designed for use with a television receiver to receive terrestrial over-the-air broadcast television signals from a te
Reflective array antenna
…this would require the reflector to be placed at 1⁄4 of a wavelength behind the elements, and this can be seen in many common reflector arrays like television antennas. However, there are a number of factors that can change this distance, and actual reflector positioning varies. Reflectors also have the advantage of…
Two Yagi-Uda type outdoor antennas mounted at the side of a building.
Two Yagi-Uda type outdoor antennas mounted at the side of a building.
A rabbit ears indoor antenna. This model also has a loop antenna for UHF reception.
A rabbit ears indoor antenna. This model also has a loop antenna for UHF reception.
A loop antenna for UHF reception. This model also has two telescopic poles for VHF. It also has a mains-powered amplifier to improve signal strength.
A loop antenna for UHF reception. This model also has two telescopic poles for VHF. It also has a mains-powered amplifier to improve signal strength.
The 'rabbit ears' antenna with its coaxial plug
The 'rabbit ears' antenna with its coaxial plug