A Wideband Calibration-Free D-Band Passive Phase Shifter With Frequency-Invariant Codes Over 24% Fractional Bandwidth

This work presents a compact 110 to 140 GHz bi-directional D-band passive phase shifter based on combining a 5-stage capacitively-loaded reflective-type phase shifter (RTPS) with a wideband 0∘/180∘ stage. The design achieves a 360∘ phase range with a resolution of 11.25∘. By applying: (1) a wideband RTPS design methodology on the stage level, (2) frequency/switching-staggering techniques among the RTPS stages, and (3) a balun-staggering technique into the 0∘/180∘ stage, the design achieves calibration-free operation with frequency-invariant codes over 24% fractional bandwidth (FBW). The design is implemented in GlobalFoundaries 22-nm CMOS FD-SOI technology with a compact core area of 130 μm × 480 μm. It achieves measured RMS phase and magnitude errors lower than 2.38∘ and 0.63 dB respectively across the entire operating bandwidth using the same frequency-invariant codes.