radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a tr ...

systems, a biconical antenna is a broad-

bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...

antenna made of two roughly conical conductive objects, nearly touching at their points.Zhuohui Zhang,''Analysis and design of a broadband antenna for software defined radio'', ProQuest, 2007 , page 6 Biconical antennas are broadband dipole antennas, typically exhibiting a bandwidth of three

octaves In music, an octave ( la, octavus: eighth) or perfect octave (sometimes called the diapason) is the interval between one musical pitch and another with double its frequency. The octave relationship is a natural phenomenon that has been refer ...

or more. A common subtype is the bowtie antenna, essentially a two-dimensional version of the biconial design which is often used for short-range

UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...

television reception. These are also sometimes referred to as butterfly antennas. Schwarzbeck RE 1790

Properties

The biconical antenna has a broad bandwidth because it is an example of a traveling wave structure; the analysis for a theoretical infinite antenna resembles that of a

transmission line In electrical engineering, a transmission line is a specialized cable or other structure designed to conduct electromagnetic waves in a contained manner. The term applies when the conductors are long enough that the wave nature of the transmi ...

. For an infinite antenna, the

characteristic impedance The characteristic impedance or surge impedance (usually written Z0) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction i ...

at the point of connection is a function of the cone angle only and is independent of the frequency. Practical antennas have finite length and a definite resonant frequency. A simple conical monopole antenna is a wire approximation of the solid biconical antenna and has increased bandwidth (over a simple monopole).

Applications

Biconical (or "bicon") antennas are often used in electromagnetic interference (EMI) testing either for immunity testing, or emissions testing.

Advantages and drawbacks

While the bicon is very broadband, it exhibits poor transmitting efficiency at frequencies at the low end of its range, resulting in low field strengths when compared to the input power. Log periodic dipole arrays,

Yagi–Uda antenna A Yagi–Uda antenna or simply Yagi antenna, is a directional antenna consisting of two or more parallel resonant antenna elements in an end-fire array; these elements are most often metal rods acting as half-wave dipoles. Yagi–Ud ...

s, and reverberation chambers have shown to achieve much higher field strengths for the power input than a simple biconical antenna in an anechoic chamber. However, when the goal is to fully characterize a modulated or impulse signal, rather than merely measuring peak and average spectrum energy content, a reverberation chamber is a poor choice for a test environment. Butterfly television antenna

References

External links

Antenna-Theory.com Bow Tie Antenna Page

Home made video
{{Authority control Radio frequency antenna types

Properties

Applications

Advantages and drawbacks

See also

References

External links