The document discusses plasma antennas, which use ionized gas or plasma instead of metal for signal conduction. Plasma antennas have several advantages over traditional metal antennas, such as the ability to focus beams, transmit short pulses, and reconfigure frequency and direction electronically. Different types are described, including laser-induced antennas and those using tube structures. The document explains that plasma antennas work by generating localized plasma concentrations that act as mirrors to deflect radio frequency beams. Potential applications include military, aviation, and broadband communications uses.
2. Outline
Introduction
Features of Plasma Antenna
Characteristics of Plasma Antenna
Types of Plasma Antenna
Working Principle
Advantages
Applications
3. Introduction
What is Plasma?
It is a gas in which certain portion of
particles are ionized. It responds strongly
to electromagnetic fields.
4. Plasma Antennas
Plasma Antennas is a type of radio
antenna currently under development.
Plasma is used instead of metal for
conduction.
They can be used for both transmission
and reception.
5. Features
Ability to focus a single beam.
Can communicate signals in very short
pulse.
Are Reconfigurable for frequency,
bandwidth, gain, length of plasma column
and radius of glass tube.
Can transmit and receive for same apertures
if the frequencies are widely separated.
6. Characteristics
Gas ionizing process can manipulate
resistance and when deionised, the gas
has infinite resistance and doesnt
interact with RF radiation.
After sending pulse, it can be deionised
and eliminates "ringing effect".
It can operate up to 90 GHz.
7. Types of Plasma
Antennas
Laser Induced Antenna
Plasma Antennas Using Tube Structures
Explosively Formed Plasma Dielectric
Antennas
8. Laser Induced
Antenna
The transmission was realized along a
plasma channel that was created by the
atmosphere breakdown.
The atmosphere breakdown was created
by the focused laser emission.
The laser is used to designate the path of
the antenna while an electrical discharge is
employed to create and sustain the
plasma.
9. Plasma Antennas
Using Tube Structures
Using tube structures, we can achieve
low base-band noise for HF and VHF
transmission.
When the plasma creating voltage is
turned off, the antenna effectively
disappears.
11. Plasma Dielectric
Antenna
A simple explosive charge design, called a
plasma cartridge, can be used to generate a
column of ionized gas.
In this design. 1-3 grams of seeded explosive
charge, which contained Fe, Pb, C, N, K, Cl,
and O was used to create plasma.
Due to high temperatures generated by the
explosive material, the surrounding gases
became ionized, forming a plasma column.
12. Plasma Dielectric
Antenna
The maximum attainable temperature that
can be achieved is dependent upon the
available oxygen for the fuel
recombination.
It has been proven that a plasma jet
antenna is feasible.
14. Working Principle
A plasma antenna generates localized concentrations
of plasma to form a plasma mirror which deflects an RF
beam launched from a central feed located at the focus
of the mirror.
An ionized region, or solid state plasma, can be
generated in silicon using electronically controlled
devices (plasma diodes) that are positioned between
closely spaced metalized surfaces which constrain the
beam.
The plasma can be freely moved by switching groups of
plasma diodes on and off that follow the desired
geometry of the reflector.
15. Working Principle
The resulting pattern forms a rosette of
overlapping reflectors only one of which is
active at any time.
This enables the beam to be steered quickly
without the need for mechanical motion.
When supply is given to the tube, the gas inside
it gets ionized to plasma. When plasma is
highly energized, it behaves as a conductor.
16. Working Principle
Antenna generates a localized concentration of
plasma to form a plasma mirror that deflects RF
beam launched from a central feed located at
focus of the mirror.
When plasma jet enters into the spiral field,
signals are emitted. The spiral is localized
concentration of plasma. These spirals behave
as plasma mirrors which help in transmission of
RF signals.
18. Advantages
Plasma posses a high level of conductivity.
Based on the frequencies used, a plasma
antenna may be able to receive signals that
would not be detectable by older types of
antennas, as well as boost signals that are then
transmitted out to either point.
a plasma antenna is much less susceptible to
electrical damage and can often be repaired
much faster if some event does occur to
temporary interfere with its function.
19. Applications
Military applications for its stealth, weight and
easily reconfiguration.
Unmanned air vehicle sensor antennas.
Detection and tracking of ballistic missiles.
Telemetry.
Broad-band communications.
Ground penetrating radar.
Wind shear detection and collision avoidance.