A reactively loaded aperture antenna array

The use of variable reactive loads to control the beam direction of an antenna array consisting of closely spaced waveguide-backed dielectric-filled rectangular slots is considered. Only the center waveguide is driven (no complex feed network is required for the array), and the other waveguides are short circuited at specified distances to provide reactive loading. The solution uses the method of moments applied to the integral equation for the equivalent magnetic current in the aperture region. The initial, design of the array is obtained by resonating the complex excitation voltages required for maximum gain with all of the elements driven. This is then improved by an optimum seeking univariate search method. Computed results are given for seven- and fifteen-element aperture arrays.