A study of a reactively loaded finite planar rectangular waveguide antenna array

The antenna arrays considered have a single waveguide-fed aperture, no complex feed network to all of the apertures, and one reactive load (shorted waveguide) for each remaining aperture. Each antenna is characterized in terms of power gain, bandwidth, and match. Several examples of magnitude pattern synthesis are presented to show antenna pattern limitations for a given antenna geometry and excitation. In addition, an example using a double frequency synthesis procedure is given for reshaping gain versus frequency characteristics in the endfire direction. Numerical techniques (optimization algorithms) are used to find reactive loads for both maximum gain in a specified direction and synthesized pattern. A brief summary is given of the major computer program subroutines used in generating the calculated results.