A 36-40 GHz Full 360° Ultra-Low Phase Error Passive Phase Shifter with a Novel Phase Compensation Technique

A 36-40 GHz full 360 degrees ultra-low phase error passive phase shifter with a novel phase compensation technique is presented in this paper. The proposed phase shifter consists of a four-way quadrature power divider as a vector generator, vector selector and two digital controlled artificial dielectric (DiCAD) phase shifter cells to achieve 4-bit (22.5 degrees phase resolution) and full 360 degrees synthesizing. DiCAD phase shifter cells not only provide 22.5 degrees and 45 degrees phase shifts but can also compensate the phase error due to its tuning mechanism. The measured RMS phase and gain error are under 2.6 degrees and 2.6 dB over 36-40 GHz, respectively. The average insertion gain is about -20.2 dB with no dc consumption. Implemented in 90-nm CMOS, the chip size is 0.75 x 0.4 mm(2) without pads. To the authors' knowledge, this phase shifter demonstrates the lowest RMS phase error among other reported millimeter-wave phase shifters.