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° 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° phase resolution) and full 360° synthesizing. DiCAD phase shifter cells not only provide 22.5° and 45° 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° 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 × 0.4 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> without pads. To the authors' knowledge, this phase shifter demonstrates the lowest RMS phase error among other reported millimeter-wave phase shifters.