Modified backfire lowers cross-polarization levels

The considered backfire antenna is essentially a leaky cavity antenna with electromagnetic characteristics which are, in a certain sense, comparable to those of a laser cavity. A long backfire antenna can be suitably modified with a small strip reflector for frequency-reuse applications where a low level of cross-polarization is required between signals in the E and H planes. The modification of phase velocity is discussed along with the results of experiments performed simultaneously at two discrete frequency bands, including the ranges from 8.6 to 9.0 GHz and from 9.9 to 10.4 GHz.