V-band Vector-sum Phase Shifter with Frequency Mixing

We developed a V-band vector-sum phase shifter with frequency mixing. The developed phase shifter consists of two VGAs (Variable Gain Amplifiers) deployed in an IF path, a QMIX (Quadrature-Mixer) which combines output signals of the VGAs in a RF path and a PPF (Poly Phase Filter) power divider in a LO path as a 90-deg. divider. The proposed phase shifter controls phase of input IF signal based on amplitude of two IF signals and converts the input IF signal to RF, simultaneously. We implemented the V-band phase shifter using SiGe BiCMOS 0.18um process. The developed phase shifter operated in wide bandwidth from 70 MHz to 1 GHz and achieved average gain of 2.3 dB, phase error of 5.5 deg.rms, and the amplitude error of 0.4 dBrms.