N-Bit L-Band Phase Shifters for Phased Arrays

Phase shifters required for electronic beamsteering in phased arrays are typically built with a small number of discrete bits. At the lower microwave radar frequencies, a large number of bits is desired to both reduce sidelobes and perform adaptive beamforming. Continuously variable phase shifters with infinite resolution have been built at L-band (1.3 GHz). Two phase shifters are reported on: a 360° unit which is a hybrid of all GaAs components, and a fully monolithic 90° shifter made in silicon-on-sapphire.