Abstract
This letter presents a 3-6-GHz wideband compact 6-bit phase shifter (PS) in 0.5- \mu \text{m} GaAs pHEMT process. It combines a 3-bit enhanced high-pass/low-pass topology, a 2-bit modified low-pass/resonator topology, and a 1-bit switched-filter structure, with optimized cascade order to achieve a bandwidth (BW) up to 66.7%. Since the proposed PS consists of lumped elements and minimized the number of switches and inductors, it achieves a compact core size of 1.214 mm 2 . The 64-output state PS exhibits high phase resolution of 5.625° with an rms phase error (PE) of less than 4°, and an insertion loss (IL) less than 6.7 dB at 3-6 GHz. To the best of our knowledge, this PS achieves the largest BW with the smallest chip size among the published 5-bit/6-bit GaAs/GaN PSs over a similar band.