Microwave radiation force on a parallel-plate resonator

A simulation method is proposed and tested in order to determine the radiation force on metal targets, whose size is comparable to wavelength. The method is based on the MoM solution of the electric field integral equation, accurate calculation of the near fields, and removal of the self-interaction terms responsible for the pinch effect. The method is used to determine the local force distribution for a parallel-plate metal resonator and a circular disk resonator at plane wave incidence. It is observed that, at the resonance, the individual metal plates may experience very large local force densities, despite the fact that the net radiation force still remains very small.