An X-band 6-bits highly-accurate digital-stepped phase shifter MMIC for phased array system

This paper presents an X-band 6-bits highly-accurate digital-stepped phase shifter MMIC for phased array system. The proposed phase shifter employs high-pass/low-pass filter topology and an improved embedded device type topology to realize 64 states of uniform phase shift and reduce insertion loss at the same time. The MMIC is fabricated using 0.25umGaAs process. It has a maximum phase shift range of 354.375 ° with 5.625 ° steps. The proposed phase shifter exhibits RMS phase error of less than 1.5 °, and RMS amplitude error of less than 0.27 dB at 8-12 GHz. The insertion loss is 6.4 dB at10 GHz. The input 1-dB compression point is 29 dBm at 10 GHz, and the total chip size, including pads, is 2.5 × 1.8 mm
²
.