The experimental determination of the calibrated S-parameters of a single resonant-slot array element

A simple and quick experimental method has been developed for experimentally determining the calibrated scattering parameters of a single resonant-slot array element. The obtained calibrated scattering matrix is defined at two planar interfaces directly coincident with the front and back surfaces of the metal plate surrounding the slot. This measurement method determines different scattering matrices for the same slot, depending on the type of waveguide and the specific waveguide mode used to feed it. An example of a calibrated transmission response of a single slot, excited by the fundamental TE/sub 11/ mode of the cylindrical cavity used to feed it on either side, is presented. The slot resonance appears to be very wide and there is hardly any transmission-phase lag at its center.<>