Experimental results for a focal plane array, synthesized with conjugate field method

The study analyses the performance of a focal plane array in combination with reflector systems of small F/D parameter (F/D<0.5). The geometries of two radio telescope reflector antennas (WSRT and Parkes) were used while the array feed was optimised for the WSRT reflector antenna only. Synthesis of the array feed was done with a dense Vivaldi array operating in a frequency band of 2-5 GHz. Conjugate field matching (CFM) in the focal area of the reflector was applied to determine the required number of array elements, arrangement and the optimal excitation coefficients. To verify the theoretical model, measurements of the array feed were carried out with a near-field scanner. The experimental results were used as an input source in the GRASP simulator to predict the far-field patterns of the WSRT and Parkes reflector antennas.