Effects of low noise amplifier under high power microwave back-door coupling

The back-door coupling effects of the low noise amplifier (LNA) under high power microwave (HPM) has been studied in this paper. First, a low noise amplifier is designed by the circuit simulation software Advanced Design System (ADS), then the LNA circuit is imported in to the High Frequency Simulator Structure (HFSS) to carry out the hybrid analysis of back-door coupling effects of HPM on LNA. We get the voltage of the gate and drain terminals of the LNA transistor. After that, the voltage is regarded as an interference signal, and is added to the transistor's corresponding pin, which is simulated by ADS. All above operations are aimed at comparing the changes in gain and noise figure before and after adding the interference signal to the LNA. At last, it is concluded that special protection should be put on signal input pins, and this can be used as a guide to provide protection to the LNA from back door coupling of high power microwave in application.