Shared-Aperture Ka-Band Reflectarray and X-Band Phased Array for Broadband Inter-Satellite Communication

In this communication, a dual-band shared-aperture reflectarray (RA) with a phased array is proposed for intersatellite links (ISLs). The Ka-band RA is integrated with an X-band phased array by a sharing mushroom patch structure. The high-frequency ratio allows the high-frequency RA and the low-frequency broadband phased array to operate independently to support high-speed communication of the geostationary orbit (GEO) relay nodes in the intersatellite network. To verify this concept, a prototype of the antenna is designed and fabricated, and its electrical performance is measured. The RA presents a peak gain of 30.1 dBi (28 GHz) and a 3 dB gain bandwidth of 11.4% (26.4–29.6 GHz). The phased array presents the peak gain of 21.7 dBi (9 GHz), and the relative bandwidth can reach 45.3% in the boresight direction. The scanning range can cover ±45°, and the H/E planes scan gain losses are less than 2.34 and 4.33 dB, respectively.