Research On Plasma-Based Electronic Scanning Smart Antenna

The plasma antenna is a novel stealth antenna based on a new concept, which has a wide application background and tremendous development potential in the military field. It has been hotly investigated in the area of novel stealth antenna. The function of the antenna radiation and stealth can be realized by utilizing characteristics of"high-pass filter"for plasma. This dissertation mainly includes the interaction of plasma and electromagnetic waves, theory and test of plasma antenna.Firstly, several fundamental parameters and generation method of plasma are presented. Then, Wentzel-Kramers-Brillouin(WKB) method and two typical finite-difference time-domain (FDTD) methods are introduced. The evolutions in attenuation and phase of electromagnetic waves which enter into unmagnetized and magnetized Inhomogeneous plasma at different angles are calculated by using WKB method. The reflection and transmission coefficients are calculated by using FDTD method.Secondly, by utilizing above methods, the software named in plasma the electromagnetic wave propagation (PWP) is systematically introduced. Several examples are given to show the property of electromagnetic wave propagation in different conditions. This software provides a simple, intuitional and fast way to calculate the propagation of electromagnetic wave in plasma. Finally, this dissertation presents the design of electronic scanning smart plasma antenna. The working principle of the plasma antenna is presented. The effect of some parameters of plasma antenna such as plasma frequency, plasma collision frequency and length of the plasma column on the characteristics of plasma antenna is analyzed. By controlling the incentive power of the plasma columns cladding, plasma antenna reconfiguration can be achieved rapidly without changing the physical structure. Four basic structures of the smart plasma antenna, including window plasma antenna, the Yagi plasma antenna, reflector plasma antenna with a director and double window plasma antenna, are simulated and analyzed by CST MICROWAVE STUDIO. Meanwhile, we design the prototype antenna and test the property of plasma gas ionization, plasma reflector and the prototype antenna. The results show that this antenna can not only increase the signal strength on the direction of the plasma window but also decrease the signal strength on opposite direction of the window.