The Rectangular Cavity Slot Antenna with Homogeneous Isotropic Loading

摘要

The rectangular cavity slot antenna, with dielectric or magnetic loading, and with a compound iris in the aperture plane, is analyzed utilizing variational techniques to derive accurate design guides for efficiency, bandwidth, and resonant frequency. The problem is broken up into several steps. First, the admittance of a loaded semi-infinite wave-guide opening out into an infinite ground plane is analyzed using variational techniques. Next, the effect of the compound iris is analyzed. A stationary expression is obtained for the admittance of a loaded semi-infinite waveguide opening out into an infinite ground plane, with a compound iris in the aperture plane. This expression is evaluated using two different approximations of aperture field. Finally, the effect of the feed and the finite length of the cavity are taken into account by, respectively, perturbation techniques and network transformations. (Author)