Study on the influence of coil configuration on electromagnetic characteristics of inductively coupled plasma superimposed frequency selective surface

Aiming at the limitation of frequency selective surface (FSS) used in radome, a new type of active frequency selective surface (AFSS) based on inductively coupled plasma (ICP) is proposed. The structure consists of a square plasma discharge cavity with a size of 20 × 20 × 5 cm3 and a FSS with broadband bandpass response. By comparing the simulation results of COMSOL Multiphysics with the experimental results of microwave interference diagnosis, the influence of coil configuration on the characteristic parameters of ICP source is analyzed. The transmissivity of ICP-FSS with different coil configurations was measured by time domain measurement system. The experimental results show that the bandwidth of passband of the structure is 6.4 GHz–19.1 GHz when the ICP source is not excited. When the ICP source is excited, the ICP-FSS structure presents different stopband transmission characteristics under different coil configurations. The bandwidth of stopband widens as the RF power increases, and the transmission coefficient valley also increases, which can effectively reduce the detection probability of the radar in the off state. Therefore, the proposed AFSS based on inductively coupled plasma is an effective candidate for radome application.