PLASMA ANTENNA

BY, S . SWETHA - 14251A1744 K . VYSHNAVI - 14251A1730

ANTENNAAntenna is a metallic structure used to propagate EM wave such that maximum intensity is in intended direction.It is an electromagnetic radiator, transducer,

sensor and impedance matching device used in systems such as radio broadcasting ,

broadcast television, radar etc.

What is ‘PLASMA’?Fourth state of matterPlasma can be defined as a set of

quasi-neutral particles with free electric charge carriers which behave collectively

LIGHTENING NEON LIGHTS

PLASMA ANTENNA It is a type of radio antenna currently

in development in which plasma is used instead of the metal elements of a traditional antenna.A plasma antenna can be used for both transmission and reception.

• Plasma antenna technology employs ionized gas enclosed in a tube (or other enclosure) as the conducting element of an antenna

• Plasma antennae can be configured to operate up to 20GHz.

• Plasma allows radio frequency signals to be transmitted or received as ionized gas is an efficient conducting element.

• If W > Wp. EM wave frequency is greater than plasma frequency (an inherent property of plasma), so wave propagates in plasma and the plasma has dielectric properties which are electrically controllable.

• If W < Wp. The wave is vanishing with the plasma medium. The wave can be absorbed or reflected depending on the collision frequency.

• The Nyquist formula states that the noise power is proportional to temperature However, the Nyquest formula assumes that the electron collision rate is much higher than the applied frequency.

RKT

• This is not always true in a plasma. If the collision rate is smaller that the applied frequency, the noise in this frequency range is greatly reduced.

Thermal noise in plasma antenna……

Methods of producing radiations:

There are two methods of producing radiation: m-radiation method

d-radiation method

Specifications Traditional Antenna Plasma Antenna

Construction Metal Plasma

Power Lower Higher

Efficiency Low High

Weight Higher Lower

Size Large Small

Ringing Effect Yes No

Transmission/Reception Uses RF sinusoidal signals

Uses short pulse during the time of transmission/reception

Noise HigherLower, plasma antenna has low collision rates among its charge carriers.

Comparision of radiation patterns:

Block diagram of simple monopole plasma antenna

Directivity comparision at 1GHz

Gain comparision at 1GHz

ADVANTAGESInvisible to radarNo ringing effectMore efficientDynamically reconfigurableFast transmissionLow interferenceHigh gainWide bandwidthResistant to electronic warfare

DISADVANTAGESComplex DesignMore power consumptionAlways stable and repeatable

plasma volumes are requiredCost required for ionising plasma

is moreMaintenance to repair or replace

the unit components will be high

APPLICATIONSRadio and television broadcastingSpace communicationsMilitary applicationsFaster internetPublic safety networks

AVAILABLEAvailable Plasma Sonics Ltd. Co.Specifications Glass -Pyrex Tube Length > 3 Tube Diameter -25mm Mount Dimensions- 12.5 inches X 21 inches Price: $ 380

CONCLUSIONTechnology Currently being under

development Could greatly impact future of

communicationsBetter performance than metal antennas

REFERENCES Journals and websites [1]Kumar, Rajneesh; Bora, Dhiraj; , "A reconfigurable

plasma antenna,"Journal of Applied Physics, vol.107, no.5, pp.053303-053303-9, Mar 2010

[2] Xue-Shi Li; Fan Luo; Bin-Jie Hu; , "FDTD Analysis of Radiation Performance of a Cylinder Plasma Antenna," Antennas and Wireless Propagation Letters, IEEE, vol.8, no., pp.756-758, 2009 doi: 10.1109/LAWP.2009.2022963

http://www.plasmas.org/what-are-plasmas.htm http://www.essortment.com/plasma-fourth-state-

matter-40444.html http://intuitor.com/resonance/radioTVres.html http://www.plasmasonics.com/tube.html