D-Band 360° Phase Shifter with Uniform Insertion Loss

This paper presents a D-Band phase shifter for 120 GHz phased array transceivers, implemented in 120 nm SiGe BiCMOS process (fT/fmax=260/340 GHz). The proposed phase shifter employs two stages of reflection-type topology for 0–180° operation, preceded by a Balun-based phase inverter to obtain a full 360° phase shift with 11.25° resolution. The phase shifter exhibits uniform insertion-loss characteristic with less than 1 dB insertion loss variation over all phase states. The measured IL at 122 GHz is 5.8±0.3 dB. Measured RMS gain and phase error at 122–123 GHz are <0.2 dB and <3°, respectively. The IC occupies area of 750 × 540 µm² and consumes 30 mW.