Ads
related to: full wave vs half antenna technology for sale near me craigslist 92119 zip
Search results
Results From The WOW.Com Content Network
A halo antenna, or halo, is a center-fed 1 2 wavelength dipole antenna, which has been bent into a circle, with a break directly opposite the feed point. The dipole's ends are close, but do not touch, and the ends on either side of the gap may be flared out to form a larger air gap capacitor, whose spacing is used to fine-adjust the ...
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.
Quarter-wave whip antenna on an FM radio for 88–108 MHz. Rubber ducky antenna on 446 MHz UHF walkie-talkie with rubber cover removed. VHF ground plane antenna. Mast radiator antenna of medium wave AM radio station, Germany. 'T' antenna of amateur radio station, 80 ft high, used at 1.5 MHz.
Dipole antenna used by the radar altimeter in an airplane. Animated diagram of a half-wave dipole antenna receiving a radio wave. The antenna consists of two metal rods connected to a receiver R. The electric field (E, green arrows) of the incoming wave pushes the electrons in the rods back and forth, charging the ends alternately positive ...
The simplest Fresnel zone plate antenna is the circular half-wave zone plate invented in the nineteenth century. The basic idea is to divide a plane aperture into circular zones with respect to a chosen focal point on the basis that all radiation from each zone arrives at the focal point in phase within ±π/2 range.
It is a simple half-wave dipole antenna used to receive the VHF television bands, consisting in the US of 54 to 88 MHz and 174 to 216 MHz , with wavelengths of 5.5 to 1.4 m (18 to 5 feet). It is constructed of two telescoping rods attached to a base, which extend out to about 1 m (3.3 feet) length (approximately one-quarter wavelength at 54 MHz ...
In radio engineering, an antenna (American English) or aerial (British English) is an electronic device that converts an alternating electric current into radio waves (transmitting), or radio waves into an electric current (receiving). [1][2] It is the interface between radio waves propagating through space and electric currents moving in metal ...
Antenna designs incorporating metamaterials can step-up the radiated power of an antenna. The newest metamaterial antennas radiate as much as 95 percent of an input radio signal. Standard antennas need to be at least half the size of the signal wavelength to operate efficiently. At 300 MHz, for instance, an antenna would need to be half a meter ...