A 57–66 GHz reflection-type phase shifter with near-constant insertion loss

Integrated 60-GHz reflection-type phase shifter (RTPS) with near-constant insertion-loss for phased array transceivers is demonstrated in this paper. The RTPS is based on a cascaded couplers structure and implemented in a standard 0.12 μm SiGe BiCMOS process, using CMOS features only. The phase shifter is controlled by a 6-bit DAC and achieves >200° phase variation across the 57-66 GHz band with less than ±0.5 dB insertion loss variation over all phase states. The measured insertion loss at 60 GHz is 7.4 ± 0.25 dB. Measured RMS phase error is less than 2.6° and the RMS gain error is less than 0.3 dB over the 57-66 GHz range. The IC occupies area of 400 × 700 μm2 (0.28 mm2), excluding pads.