A 6-bit Active Phase Shifter for Ku-Band Phased Arrays

This paper presents a 6-bit active phase shifter in 0.13-mu m SiGe BiCMOS technology for Ku-band phased arrays based on a phase interpolation technique. An input Marchand balun and a RC poly phase filter are used for high I/Q accuracy wideband quadrature generation with high linearity and an integrated current-mode DAC is used for controlling the amplitude of I/Q path signal to achieve 6-bit phase resolution. The phase shifter operates in the 12-18 GHz range. The simulation results show an rms phase error less than 2.61 degrees. The average insertion gain ranges from -11.16 dB to -20.39 dB with an rms gain error less than 0.4 dB for 64 phase states. The phase shifter achieves an input P1dB of 9.98 dBm at 16 GHz for 0 degrees-phase state. The core area of the phase shifter is 1.1x0.9 mm2, with a total current consumption of 13.4 mA from a 3.3 V supply voltage.