Transmission characteristics of Plasma-based microwave absorbing panel in Near and Far field region of testing antenna

Microwave absorbers come in variety of types depending upon their operational frequency regime, environment of application, type of operation and several other physical parameters. Plasma-based microwave absorbers are of importance because of its adaptive nature. This paper is an attempt to study the Transmission characteristics of two types of Plasma-based microwave absorbing panels in the X- band viz. 8–12 GHz. A plasma panel is formed by series of fluorescent tubes enclosed in two different shapes of Teflon enclosures. A free space Transmission tunnel method is adopted to study the transmission properties of both plasma panels. The experiment has been carried out in an anechoic chamber using standard gain horn antennas. The panels are tested in the near and far field of the test antenna and the results are discussed. The difference in the transmitted microwave power with and without plasma gives the information about the absorption of the power. An average of 60% of microwave power is absorbed when the plasma is turned on. This makes the panel an attractive solution for using it as an active microwave absorber.