Experimental Synthesis of a Feed Pattern with a Dense Focal Plane Array

The 8×9 element dense tapered slot array operating over 1-7 GHz range is used to synthesize a dual-band (2.215-2.375 GHz and 4.770-5.020 GHz) feed for a F/D=0.35 reflector. Only 25 elements are excited in a concentric ring manner to simulate a conventional coaxial feed. Not only experiments, including mutual coupling effects, but also array simulations using the cos2 element power pattern give a satisfactory approximation. Recommendations of how to choose the sufficient overall dimensions of the dense array feed are developed on the basis of the focal field distribution analysis. Power losses of no more than about 5% at the boundaries of the given band relatively to the central frequency serve as a criterion determining the maximal efficiency of the reflector aperture.