A Compact 53 - 62 GHz Phase Shifter With Series Peaking Technique in 40-nm CMOS Technology

This brief presents a 53 - 62 GHz phase shifter (PS) with 6-bit active vector synthesised for Millimeter (mm) wave communication. In order to avoid capacitance deviation during production and processing, which has an impact on the quadrature generator circuit (QGC), a compact, vertical stacking capacitor-free QGC based on a folded transformer is proposed for I/Q signal generation and area saving. To improve the RMS gain and phase errors, a pair of DAC MOSFET cells for each quadrature signal which turn on and off complementarily is adopted. To avoid the bandwidth limitation of PS due to the large equivalent parasitic capacitance from the pair of DAC, a transformer-based series peaking technique is proposed for bandwidth extension. The measurement result shows that the proposed PS achieves a 3-dB bandwidth of 53 - 62 GHz. The RMS phase error is 1.3 - 2.4 deg and the RMS gain error is 0.4 - 0.55 dB within that bandwidth. The core area of the PS is only 240 um \times 570 um.