A coaxial antenna (often known as a coaxial dipole) is a particular form of a half-wave
dipole antenna, most often employed as a vertically
polarized omnidirectional antenna
In radio communication, an omnidirectional antenna is a class of antenna which radiates equal radio power in all directions perpendicular to an axis (azimuthal directions), with power varying with angle to the axis ( elevation angle), declining ...
.
History
Arnold B. Bailey was granted the US patent 2,184,729 ''Antenna System'' on December 26, 1939 after filing in 1937 for a vertical antenna providing coaxial element sleeve structures.
Bonnie Crystal was granted th
US patent 7,151,497 ''Coaxial Antenna System''on December 19, 2006 after filing in 2003 for new types of coaxial antennas with reduced size providing efficient broadband, wideband and controlled bandwidths, using radiation by the outside of the coaxial elements.
Coaxial Antenna System patent number 7151497
Configuration
In the most basic form, a quarter-wavelength section of coaxial cable is prepared such that the inner and outer conductors are separate but still attached to the remaining cable.
The outer (shield) conductor is connected to a quarter-wavelength conducting sleeve into which the cable is inserted, and the inner conductor protrudes vertically above the sleeve for a quarter-wavelength. Also, additional quarter-wavelength sections may be connected to the outer conductor to form a better ground plane.
Bazooka Dipole coaxial antenna
Dipole antennas constructed using coaxial cables with shorted ends are often given the name "Bazooka" dipoles.
See also
* Amateur radio
*Antennas
In radio engineering, an antenna or aerial is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an ...
* Coaxial cable
* Dipole antenna
External links
Bailey's 1939 patent (PDF)Coaxial Antenna System patent number 7151497
Radio frequency antenna types
Antennas (radio)
{{radio-comm-stub