Research on plasma antenna based on inductively coupled feeding structure

In this paper, an inductive coupling feeding structure is proposed. Then a plasma antenna prototype is designed and measured based on this inductive coupling feeding structure. This antenna is composed of the fluorescent tubes filled with low pressure gas, an inductive coupling feeding structure, and a microwave feeding line. The inductive coupling feeding structure is a solenoid structure which is wrapped around the fluorescent tubes. The microwave signal is excited into the plasma through the inductive coupling feeding structure. The dependence between the microwave feeding structure and the plasma is significantly reduced due to the magnetic coupling. Then the designed antenna has excellent reconstruction characteristics by only changing the coupling inductance of the inductive coupling feeding structure. The effectiveness of the proposed antenna is verified by using the measured reflection coefficients and transmission coefficient before and after establishing the plasma states. Experimental results show that the reflection coefficient of the antenna is decreased from -2.07dB to -34.36dB at the frequency point of 382.4MHz. At the same time, the transmission link level is significantly improved after the plasma state is established.