A high XPD performance design method for satellite CFRP dual‐reflector antenna without metallizing reflectors

Abstract

The depolarization effect of carbon‐fiber reinforced plastics (CFRP) reflector is studied and a cross‐polarization discrimination (XPD) compensated method for dual‐reflector antenna without metallizing reflectors is presented in the paper. By setting the fibers direction of the main reflector orthogonal to that of the subreflector, the phase difference of the reflected electric field components from the first‐ and second‐layer of the CFPR sandwich can be compensated and depolarization effect would not happen. A dual‐reflector antenna operating at Ku band is designed, simulated and measured. The measured XPD of both the compensated and uncompensated designs are compared, and results show that XPD improves more than 3.0 dB. This method is a valid and low‐cost solution for dual‐reflector antennas in circular polarization to pursue excellent XPD performance, which is highly suitable for satellite larger‐aperture CFRP reflector antennas.

Design of multibeam antenna with ultralow cross‐polarization

“…However, the asymmetry of reflector structure itself leads to the deterioration of cross‐polarization (XP) and the value is generally about −25 dB, 4,5 which does not meet the high requirement in some special system. To improve the XP performance, the common scheme is (1) increasing the focal length to weaken the effect of the asymmetry on the XP performance 6,7 ; (2) reshaping the surface of the reflector to change the amplitude and phase distribution of surface field, then to improve the XP performance 8,9 ; (3) redesigning the feed to let it operate at the multimode state to improve the XP performance 10–12 ; (4) using dual‐reflector to suppress the XP performance 13 . However, increasing the focal length will be limited by the satellite structure, and the improvement effect is extremely limited.…”