Recent results for plasma antennas (original) (raw)
Related papers
Comparative Study of Plasma and Metallic Antenna
2016
Metallic antennas are right now in execution use metallic conduit as managing medium for electromagnetic Radiations. Plasma radio wires utilizes ionized medium. The plasma reception apparatus is a radiofrequency receiving antenna shaped by a plasma sections, fibers or sheets, which are energized by a surface wave. The importance of this gadget is the means by which quickly it can be turned on and off just applying an electrical heartbeat. In this paper we have examined the essential hypothesis, operation of the plasma radio antenna. We have additionally given the elements, focal points and applications for the same.
I sincerely thank my Institution, HOD and my professors without whose permission and patronage, this project would not have been a success.
Comparative study of Metal Antenna &Plasma
2015
Metal antennas currently in implementation use metallic conductor as guiding medium for electromagnetic Radiations. Plasma antennas uses ionized medium. The plasma antenna is a radiofrequency antenna formed by a plasma columns, filaments or sheets, which are excited by a surface wave. The relevance of this device is how rapidly it can be turned on and off only applying an electrical pulse. In this paper we have discussed the basic theory, operation of the plasma antenna. We have also given the features, advantages and applications for the same.
Plasma Antennas: Survey of Techniques and Current State of the Art
2003
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Application of plasma columns to radiofrequency antennas
Applied Physics Letters, 1999
Plasma offers a promising alternative to metal for a wide variety of radiofrequency antenna applications. In this letter we report measurements of efficiencies up to 50% and radiation patterns for plasma column antenna elements. It is demonstrated that the current distribution along the antenna can be controlled by the plasma density. Plasma columns can be used instead of metal elements in communications antennas.
Properties of DC-biased plasma antenna
2008 International Conference on Microwave and Millimeter Wave Technology, 2008
Plasma antenna is a general terms representing using plasma as a conductive medium to transmit or reflect signals. It has unique properties like low RCS, tunable impedance, and instant on-off capability. Previous plasma antenna uses 500 MHz 100W RF power to generate a plasma column, which is limited in energy efficiency and bandwidth. We developed DC-biased plasma antenna, which has no operation frequency upper limit and low sustaining power. Signal is coupled to the plasma antenna via capacitive coupling. Plasma antennas of different length were studied, together with variant gas filled. Positive gain can be achieved at frequencies above the plasma characteristics frequency. Some frequencies shows resonance behavior when plasma is present. Impedance shifts slightly with the DC current. Radiation pattern is less uniform than metal antenna. Gain is related to signal power. I.
Plasma sheath structures around a radio frequency antenna
Journal of Geophysical Research, 2008
A one-dimensional particle-in-cell (PIC) simulation code is developed to investigate plasma sheath structures around a high-voltage transmitting antenna in the inner magnetosphere. We consider an electrically short dipole antenna assumed to be bare and perfectly conducting. The oscillation frequency of the antenna current is chosen to be well below the electron plasma frequency but higher than the ion plasma frequency. The magnetic field effects are neglected in the present simulations. Simulations are conducted for the cases without and with ion dynamics. In both cases, there is an initial period, about one-fourth of an oscillation cycle, of antenna charging because of attraction of electrons to the antenna and the formation of an ion plasma sheath around the antenna. With the ion dynamics neglected, the antenna is charged completely negatively so that no more electrons in the plasma can reach the antenna after the formation of the sheath. When the ion dynamics are included, the electrons impulsively impinge upon the antenna while the ions reach the antenna in a continuous manner. In such a case, the antenna charge density and electric field have a brief excursion of slightly positive values during which there is an electron sheath. The electron and ion currents collected by the antenna are weak and balance each other over each oscillation cycle. The sheath-plasma boundary is a transition layer with fine structures in electron density, charge density, and electric field distributions. The sheath radius oscillates at the antenna current frequency. The calculated antenna reactance is improved from the theoretical value by 10%, demonstrating the advantage of including the plasma sheath effects self-consistently using the PIC simulations. The sheath tends to shield the electric field from penetrating into the plasma. There is, however, leakage of an electric field component with significant amplitude into the plasma, implying the applicability of the high-voltage antennas in whistler wave transmission in the inner magnetosphere.
Design and development of plasma antenna for wi-fi application
Journal of Fundamental and Applied Sciences, 2018
The term plasma is often referred to as the fourth state of matter. When sufficient ionized, plasma can be a conductor element. Plasma antenna is a type of radio antenna that represents the use of ionized gas as a conducting medium instead of metal conductors. The main objective in this research is to design plasma antenna at 2.4 GHz by using commercial fluorescent tube. In this work the commercial fluorescent lamp was chosen because it was low cost to produce plasma element. The plasma antenna in this research was made from fluorescent lamp that functioned as a radiating element with target frequency at 2.4 GHz for Wi-Fi application. The commercial fluorescent lamp consisted of argon gas and mercury vapor with a diameter of 28 mm and a length 589.8 mm. The result showed that a fluorescent tube, can be used to work as a plasma antenna for Wi-Fi application.
Numerical investigation into the performance of two reconfigurable gaseous plasma antennas
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014
Gaseous plasma antennas are devices that rely on plasma discharges to radiate electromagnetic fields. Compared to metallic antennas, they can (i) be reconfigurable in radiation pattern, frequency, bandwidth and input impedance, (ii) be tuned electrically rather than mechanically on microseconds time scales, (iii) be transparent above the plasma frequency allowing array configuration with reduced co-site interference. So far, several analytical and numerical models have been developed, though they rely on simplified plasma response. In this work we exploited ADAMANT, a full-wave numerical tool based on a set of coupled surface and volume integral equations, to fill the aforementioned gap in the study of how plasma parameters affect the performance of plasma antennas. Firstly, we simulated a plasma dipole and plasma torus for the radiated fields and input impedance. In this analysis, we considered the current distribution in the plasma volume only, thus focusing on the plasma behavior as a radiating medium. Results show that the antenna radiation pattern can be reconfigured by adjusting plasma density, and signal frequency. In the dipole case, we considered also the effect of gas type, and magneto-static field, which are negligible in high density case, i.e., n 0 > 10 18 m −3. This holds true for the real part of the impedance for both configurations, that decreases as the plasma density rises in all the working conitions simulated. Secondly, we considered a λ/2 plasma dipole, and we computed the radiated fields due to the current distributions in the plasma volume as on the metal surface. We evaluated the influence of the driving circuit geometry on the radiation pattern assessing its key role, and we compared the plasma dipole against a metallic one for gain and directivity, which turned out to be similar; the gain is lower for the plasma dipole, due to the power absorbed by the plasma. The dipole was used in a linear plasma array comprised of two dipoles with axle spacing of λ/2, filled with a cold, non-magnetized, collisional plasma, with a density n 0 = 10 19 m −3. Dipoles were excited in phase and in phase opposition; gain and directivity for different signal frequencies resemble that of an array of metallic dipoles for the same working conditions. We assessed that GPAs act similar to metal antennas when the plasma density is high enough (i.e. n 0 ≥ 10 19 m −3), but with the possibility to reconfigure the radiation pattern in both shape and intensity by varying (i) the plasma density, (ii) the working frequency, and (iii) the magneto-static field (if present), giving to plasma antenna some advantages over conventional antennas.