Electromagnetic analysis of plane wave illumination effects onto passive and active circuit topologies

The finite element-boundary integral method, incorporating the multilevel fast multipole method to reduce the storage cost of the boundary integral matrix, is applied to the analysis of two microstrip filter circuits illuminated by a plane wave. Simulated results indicate that significant voltages are induced across the output ports close to the filters' resonances. The study is further extended to a microstrip low-noise amplifier circuit. It is shown that, at certain field strengths, the plane wave illuminating the microstrip amplifier circuit can introduce considerable gain deviation and nonlinearity to its operation.