A D-band Gain-Switching Phase Shifter with Wideband and Low Temperature-Dependency in 22-nm FD-SOI CMOS

This paper describes a D-band phase shifter for a phased array antenna system implemented in a 22-nm FD-SOI CMOS process. The phase shifter employs a vector modulator-type circuit that synthesizes gain-controlled quadrature signals. The gain control circuit is realized by controlling the path of the unequal distribution synthesis circuit ON/OFF by an amplifier with an enable function. Measurements of this circuit, including temperature characteristics, confirmed that it is capable of 360 degrees phase control in approximately 5 degrees steps at 140-170 GHz, with a pass-through gain of approximately -12 dB at 150 GHz and room temperature. At 150 GHz for all phase states, the RMS phase errors and the RMS gain errors were confirmed to be 4.1 degrees and 0.28 dB, respectively. Even in the temperature range from 0 to 50 degrees C and the frequency range of 140-170 GHz, the RMS phase error was less than 6.8 degrees and the RMS gain error was less than 0.81 dB. The implementation of the circuit with only ON/OFF control of the amplifier resulted in a phase shifter with excellent stability over temperature, with little phase and gain error even when measured at room temperature +/- 25 degrees C.