Estimating the Scattering Cross Section of an Electrically Large Aperture on a High-Q Cavity

This letter shows that the contribution from an electrically large aperture on a high-
Q
cavity can be estimated statistically without using full-wave simulations. By combining the propagation principles in free space and in a highly resonant electrically large cavity, the statistical behavior of the scattering cross section can be estimated analytically. It is interesting to find that the mean value of the scattering cross section from an electrically large aperture only depends on a few macrolevel parameters but not on detailed structures. Analytical derivation and numerical verifications are given.