A miniaturized, self-actuated, energy selective spatial filter

Abstract

In this paper, a miniaturized, self-actuated, energy selective spatial filter is designed for achieving field intensity dependent electromagnetic (EM) protection in a working frequency band. The spatial filter is periodic with each unit loaded with four microwave nonlinear devices. The dimension of the unit is in size of λ/16 and is ultrathin. Structural design, mechanism of operation are presented and discussed. A full-wave simulation is carried out for obtaining the transmission characteristic of the spatial filter. Results show that the received field intensity by using the spatial filter can be well controlled with a variable power loss from 0.1 dB up to 24 dB, and the spatial filter has a stable transmission characteristic to different incident angles. Therefore, the spatial filter is able to distinguish small signals from strong incident waves and can be utilized in EM protection against high power microwaves.