The Research on Excitation Method of All-metal Vivaldi Antenna Array Feeder for FAST

In order to improve the sensitivity and efficiency of the radio telescope receiver system and to solve the problem of discontinuous field of view of the feed cluster, a phase array feed is proposed as the feed of the radio telescope, and the amplitude and phase control of the array beam is an important part of the phase array feed design. In this paper, a 61-element phased array feeder for Five-hundred-meter Aperture Spherical radio Telescope (FAST) based on all-metal Vivaldi antenna is proposed. The direct conjugate field matching (DCFM) excitation method and the indirect conjugate field matching (ICFM) excitation method are compared and analyzed. The performances of the beamforming based on the proposed feeder array is verified by co-simulation which consists of full-wave method and quasi-optical method. In the frequency range of 2-6 GHz, the aperture efficiencies above 60% are obtained.