A Compact E- Mode GaAs pHEMT Phase Shifter MMIC for 5G Phased-Array Systems

A compact 38-GHz 4-bit phase shifter using 0.15-μm GaAs pHEMT process is proposed. By Adopting the E-mode process within the switching-type phase shifter (STPS), low-loss performance is achieved in a miniaturized chip size without negative control voltage. The proposed phase shifter has 10.7-dB average insertion loss over the 36-39 GHz, and loss variation is about 1.81 dB. The measured rms phase error is 6.9° at 38 GHz. The chip size including all testing pads is 1.4 mm × 0.62 mm, and the core area is only 1.25 × 0.52 mm2. To the author's knowledge, this work presents the most compact area among GaAs Ka-band phase shifters.