A K-band eight-element reconfigurable phased-array receiver with high Tx-band rejection

Abstract

A K-band eight-element phased-array receiver is proposed, featuring a reconfigurable beam count and high Tx-band rejection, tailored for satellite communication applications. By precisely designing the inter-stage and output matching networks of the four-stage low-noise amplifier, the Tx-band rejection of the receiver can be effectively enhanced to align with the requirements of more than 35 dB in shared-aperture phased-array applications. Meanwhile, the reconfigurable power divider is meticulously designed to achieve three different operation modes, which allows the eight-element receiver to be configured for one, two, or four simultaneous beams. In addition, an active vector-modulated phase shifter is designed to meet the demands of precise phase shifts of phased-array systems. Based on the proposed method, a K-band eight-element reconfigurable phased-array receiver operating from 17.7 to 21.2 GHz is designed and measured. The measurement exhibits more than 35-dB Tx-band rejection, 21–24.5 dB for single-channel gain, and lower than 2.6 dB for noise figure within the design bandwidth. Meanwhile, the measured root mean square (RMS) gain error and RMS phase error are confined within 0.8 dB and 3.7°, respectively.