Advantages Of The Plasma Antenna Information Technology Essay

Advantages Of The Plasma Antenna Information Technology Essay An antenna is a device that sends or accepts electromagnetic waves. It changes electromagnetic waves into electric currents, and electric currents to electromagnetic waves. Antennas are used to send and receive waves from the radio frequency of the electromagnetic spectrum. Antennas are used in radio and television broadcasting, spacecraft communication, point-to-point radio communication like walkie-talkie system, hand phones, radar, and wireless LAN. An antenna is a setup of one or more electrical conductors, also called elements. In the transmission of an antenna, a voltage is applied at the antenna terminals to produce an alternating current (A.C) in the elements, thus causing the elements to produce an electromagnetic field as an effect. In reception, the reverse happens: an electromagnetic wave from an external source induces an alternating current in the elements and a matching voltage at the antenna’s terminals. Some receiving antennas use shaped reflective surfaces t o collect the radio waves hitting them and direct or focus them onto the elements. Heinrich Hertz (1857-1894) built some of the first primitive antennas in 1888 in his experiments to prove that electromagnetic waves exist as inferred by the James Clerk Maxwell’s theory. One of the antennas he built was the dipole antenna, which will be explained in detail in the Supporting Theory section of this report. He published his work and installation design in Annalen der Physik und Chemie (vol. 36, 1889). In 1919, J Hettinger was granted a patent for the concept of a plasma antenna. A plasma antenna is a type of antenna that is currently in development in which plasma is used to replace the metal elements of a normal antenna. A plasma antenna can be used for transmission and reception, just like normal radio antennas. Plasma antennas have only become practical in recent years, where high speed internet connection is an important necessity to all. Currently, Plasma Antennas (a company ) in Winchester of the United Kingdoms have developed a plasma antenna which they named Plasma Silicon Antenna or PSiAN. FINDINGS 2.1 – SUPPORTING THEORY 2.1.1à ¢Ã¢â€š ¬Ã‚ ¢ ANTENNA Here is an explanation of how a traditional antenna works. There are many types of antennas that have been designed by humans over the years but for simplicity’s sake, the explanation here will describe how a dipole antenna works. A dipole antenna is an antenna that can be built using a simple wire with a driven element in the centre. It consists of two metal conductors of rod or wire, arranged parallel and in line with each other, with a small space between them. The radio frequency voltage is applied to the driven element at the center, between the two conductors. These antennas are the most primitive practical antennas. They are used mostly in traditional â€Å"rabbit ears† television antennas. 450_wide.jpg How the antenna transmits signals: First, a voltage is applied to the ant enna terminal (in this case, the driven element in the centre) to produce a potential difference in between the opposite ends of the two conducting wires. When a potential difference exists, there will be a flow of electrons, which in turn produces a current. Say that the electrons from end A are moving towards end B at maximum speed. When they reach end B, they will stop instantaneously. End B is now negatively charged whereas end A is positively charged. The electrons are attracted to the positive charges at end A and move back towards A at maximum speed. Now, the charges at both ends are reversed. This back and forth movement of the electrons produces an alternating current in the conducting wires. When there is an alternating current in the metal conductors, electromagnetic waves are produced. These waves are the signals being transmitted by the antenna.