Abstract: A front-end chip with phase shift function was designed for K-band two-channel integrated transmitter and implemented in TSMC 90 nm CMOS technology. The chip consists of a power divider, two sets of active phase shifters and power amplifiers with different parameters. And a digital block was integrated on the chip to control phase shifters. Measurement results show that, at the center frequency 25 GHz, the gains of two channels are 19.1 dB and 18.9 dB, the output power 1 dB compression points of two channels are 9.57 dBm and 8.41 dBm, and the phase errors of two channels are 1.38° and 1.47° respectively. The power consumption is 0.32 W when the supply voltage is 1.2 V. The total chip area occupies 2.20 mm×1.25 mm.