On the reflection properties of periodically supported metallic wire gratings with rectangular mesh showing small sag

Ideal reflector simulation of wire gratings is considered. Results for infinite plane gratings under linearly polarized plane waves, based on Astrakhan´s averaged boundary conditions, yield conclusions on influence of wire orientation, mesh size, and wire connection. The grating sag is considered. Its influence on strength and phase shift of the reflection is estimated from a simple scatter problem, using Kirchhoff´s approximation. A smoothness criterion is given. The results of the work are related to an unstationary method to measure radiation patterns of aircraft antennas in flight.