Mutual Impedance of Plasma Antennas

The concept of plasma antennas array has been put forward for a long time, but the study on the mutual coupling between elements of the array is very little. In this paper, a model for antennas array involving two plasma elements is set up, where the density of element 1 is assumed to be very high and could be used as metal, and the mutual impedance between plasma elements is derived detailedly. Then, considering that the density of the plasma element 2 is uniform or non-uniform distribution, we analyse mutual impedance of the two plasma column antennas which vary with the plasma density, collision frequency inside element 2 and the distance of two elements. The result of experiment shows, under normal circumstance, the amplitudes of mutual resistance and reactance between two plasma antennas are smaller than those between two metallic antennas which has the same configure and size, and the plasma density, collision frequency inside element 2 will impact the impedance. This is very useful for beam forming and directional reconfiguration among of plasma antenna's application.