Search results
Results from the WOW.Com Content Network
The most commonly used is the center-fed half-wave dipole which is just under a half-wavelength long. The radiation pattern of the half-wave dipole is maximum perpendicular to the conductor, falling to zero in the axial direction, thus implementing an omnidirectional antenna if installed vertically, or (more commonly) a weakly directional ...
A full-wave loop antenna is slightly more than two half-wavelengths in circumference, which is a bit more than double the size of a halo antenna designed to operate on the same frequency. In contrast, the two semi-circles of a resonant loop, each is a half wavelength long. There is no gap, and each semicircle ends at the semi-circles ...
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 results in oscillation of the electrons in the rods, charging the ends alternately positive (+) and negative (−).
Hence, the monopole antenna has a radiation pattern identical to the top half of the pattern of a similar dipole antenna, and a radiation resistance a bit less than half of a dipole. Since all of the equivalent dipole's radiation is concentrated in a half-space, the antenna has twice the gain (+3 dB) of a similar dipole, neglecting power lost ...
Two element dipole array in front of a one wavelength square reflector used as gain standard. The gain of practical array antennas is limited to about 25–30 dB. Two half wave elements spaced a half wave apart and a quarter wave from a reflecting screen have been used as a standard gain antenna with about 9.8 dBi at its design frequency. [4]
Dipole field strength in free space, in telecommunications, is the electric field strength caused by a half wave dipole under ideal conditions. The actual field strength in terrestrial environments is calculated by empirical formulas based on this field strength.
The quarter-wave monopole and half-wave dipole both have vertical radiation patterns consisting of a single broad lobe with maximum radiation in horizontal directions, so they are popular. The quarter-wave monopole, the most compact resonant antenna, may be the most widely used antenna in the world.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Donate