A Frequency-Reconfigurable CMOS Active Phase shifter for 5G mm-Wave Applications

This brief presents an analog mm-wave active phase shifter utilizing a frequency-reconfigurable vector-summing topology. A frequency-tunable I/Q signal generator followed by frequency-tunable single-to differential convertors and variable gain amplifiers is employed to build the phase shifter. The designed phase shifter can be switched to operate over 24–30 GHz band or 35–41 GHz band. The phase shifter, fabricated in 90 nm CMOS technology, provides 360° of phase shifting range in both frequency bands while consuming only 17.6 mW of power and 0.34 mm2 of chip area (excluding pads). Measurement results show that the phase shifter’s RMS phase errors for 32 phase states are less than 4° and 5.1° over 24–30 GHz band and 35–41 GHz band, respectively. RMS amplitude errors of the phase shifter for 32 measured phase states are less than 0.6 dB and 0.35 dB over the lower and higher operation bands, respectively. The measured input 1 dB compression points are larger than −2.8 dBm and −3.7 dBm over the lower and higher operation bands, respectively. The proposed phase shifter, which is able to cover the released frequency bands of n257, n258 and n260, is a good candidate for 5G mm-wave applications.