Cavity-backed, aperture coupled microstrip patch antenna

The paper reports work on a new variation of the so called aperture coupled patch antenna, namely the cavity-backed aperture coupled patch antenna (CBACPA). This is an aperture coupled antenna element exhibiting broad bandwidth and low crosspolar radiation as well as suppressing surface wave propagation, thus leading to improved array performance. Further advantages of the CBACPA are improved heat transfer from the elements when active devices are used, increasing structural stability and the elimination of a low permittivity substrate material. Measurements yield a bandwidth of 20% and crosspolar radiation of -25 dB for isolated elements. Measurements on the arrays allow one to conclude that the mutual coupling between elements is indeed reduced and thus scan performance should be improved