Vertical polarized VHF- UHF biconical antenna 170 – 1100 MHz with omni directional H-plane pattern. A biconical antenna consists of an arrangement of two conical conductors which is driven by Potential, charge, or an alternating Magnetic

An omnidirectional antenna is an antenna system which radiates power uniformly in one plane with a directive pattern shape in a perpendicular plane. An antenna is a Transducer designed to transmit or Receive electromagnetic waves In other words antennas convert electromagnetic waves into This pattern is often described as "donut shaped"

$D = 10\log_{10} {\left ({101.5\over {HPBW - 0.00272(HPBW)^2}}\right )} \;\; dB$

Practical antennas approach omnidirectionality by providing uniform radiation or response only in one reference plane, usually the horizontal one parallel to the earth's surface. In electromagnetics, directivity is a figure of merit for an antenna. The decibel ( dB) is a logarithmic unit of measurement that expresses the magnitude of a physical quantity (usually power or intensity relative to In Telecommunication, the term beamwidth has the following meanings 1

Common low gain omnidirectional antennas are the whip antenna, a vertically orientated dipole antenna, the discone antenna, and the horizontal loop (or halo) antenna (Sometimes known colloquially as a 'circular aerial' because of the shape). A whip antenna is the most common example of a Monopole antenna, an antenna with a single Driven element and a Ground plane. A dipole antenna, developed by Heinrich Rudolph Hertz around 1886, is an antenna with a center- fed Driven element for transmitting A discone antenna is a version of a Biconical antenna in which one of the cones is replaced by a disc

Higher gain omnidirectional antennas are the Coaxial Colinear (COCO) antenna[2] and Omnidirectional Microstrip Antenna (OMA)[3].

Omnidirectional antennas are generally realized using colinear dipole arrays. These arrays consist of half-wavelength dipoles with a phase shifting method between each element that ensures the current in each dipole is in phase[4]. The Coaxial Colinear or COCO antenna uses transposed coaxial sections to produce in-phase half-wavelength radiatiors. A Franklin Array uses short U-shaped half-wavelength sections whose radiation cancels in the far-field to bring each half-wavelength dipole section into equal phase.