A Monolithic Single-Chip X-Band Four-Bit Phase Shifter

X-band GaAs monolithic passive phase shifter with 22.5°, 45°, 90°, and 180° phase bits are developed using FET switches. By cascading all four bits, a four-bit digital phase shifter with 5.1+-0.6-dB insertion loss is realized on a single 6.4 x 7.9 x 0.1-mm chip.