A 60-GHz 360° 5-Bit Phase Shifter With Constant IL Compensation Followed by a Normal Amplifier With ±1 dB Gain Variation and 0.6-dBm OP $_{\mathrm{ -1dB}}$
In this brief, a concise compensation technique to obtain constant insertion loss (IL) among different phase shifting states of an millimeter-wave switch-type phase shifter (PS) is developed. The main idea is to introduce switches into the PS to align ILs of all phase states to the maximum, which hardly introduces additional phase variation, degrades IL flatness, or deteriorates maximum IL. A 60-GHz 360° 5-bit switch-type PS is designed with the proposed technique in a 65-nm CMOS technology. Measured results show that the IL variation among all 32 phase shifting states is within ±0.8 dB over 57–66 GHz, with a maximum root-mean-square (rms) phase error of 8°, a gain tuning range of 8 dB and an input 1-dB power compression point (IP−1dB) of 13 dBm. The proposed PS followed by a 60-GHz normal amplifier with invariable gain is also designed and verified. A maximum gain of 4 dB is achieved with a gain variation within ±1 dB over a 9-GHz bandwidth, an output 1-dB power compression point (OP−1dB) of 0.6 dBm, a maximum rms phase error of 11.3°, and a dc power consumption of 30 mW.