A 2.2–4.2-GHz Wideband Analog Phase Shifter MMIC With Low RMS Phase/Amplitude Error

This letter presents a 2.2–4.2-GHz 360° continuous-tuned phase shifter (PS) using the Gallium arsenide (GaAs) heterojunction bipolar transistor (HBT) technology. A new method for broadband analog PS design based on a tunable low-pass network (LPN), a tunable high-pass network (HPN), and a magnetically coupled all-pass network (MCAPN) configuration is proposed to achieve uniform phase shifting and flat amplitude response at the same time for each phase-shifting state. The fabricated PS demonstrates a low average insertion loss (IL) of 4.9 dBC a low root-mean-square (rms) phase error of less than 5.5°, and a low rms amplitude error of less than 0.47 dB between 2.2 and 4.2 GHz. The proposed analog PS has the most flattened phase performance compared with previously reported pass PSs over a wide bandwidth.