A Low Profile, Broadband Circularly Polarized Beam Scanning Array

Abstract

Abstract Based on the idea of tightly coupled dipole array, a low profile, broadband circularly polarized array is designed in this paper. The circularly polarized phased array element consists of dual polarized dipoles with the same phase center and orthogonal arrangement, grounded coupling patches, resistive frequency selective surfaces (RFSS), and a 90° phase shifter network. In order to realize broadband scanning, the effect of RFSS on the input active voltage standing wave ratio and radiation axial ratio (AR) of the element is studied. The results show that the element can operate at 5-11.5GHz, within a ±45° angle scanning range, the AR of each scanning plane is less than 3dB, and the profile height is only 0.33 λ high.