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° phase control in approximately 5° steps at 140-170GHz, with a pass-through gain of approximately -12dB 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° and 0.28 dB, respectively. Even in the temperature range from 0 to 50°C and the frequency range of 140-170GHz, the RMS phase error was less than 6.8° 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°C.