Isotropic transmission cross section of loaded and unloaded apertures

The isotropic transmission cross sections of loaded and unloaded apertures have been studied. Results from numerical calculations as well as measurements are presented for three different load configurations, consisting of an absorber frame surrounding the aperture on either both or only one side. Presented results shows that, with a carefully designed absorber frame, the total transmitted power can be reduced substantially using only a small amount of lossy material. Furthermore, it is shown that identical results are obtained whether the absorber frame is placed on the side illuminated by the isotropic source or on the opposing side. Simulation and measurements results are generally in good agreement.