X-BAND Compact MMIC 4-Bit Phase Shifter for Phased Array Systems

An X-band GaAs Monolithic Microwave Integrated phase shifter for phased array antenna is designed. The phase shifter (PS) Monolithic Microwave Integrated Circuits (MMIC) provides 16 phase shift states between 0° and 360° in increments of 22.5°. The design includes high-pass/low-pass networks for the 180° and 90° phase, and switched filter networks for the 45° and 22.5° phase. The GaAs HEMTs are used as key components for controlling the phase shifter. All drain and source terminals are DC grounded while the gates are applied to 0 V or −3 V.The phase shifter obtains 5 ± 2.1 dB insertion loss and the input and output return losses are higher than 6.5 dB over the 8–12 GHz bandwidth of interest. The chip area is very compact, just about 3.5 mm x 1.6 mm, including all pads.