Constant loss miniature 45nm RF-CMOS 24 GHz phase shifter

Abstract

We present design and characterization of an integrated passive analog phase shifter at 24GHz in a commercially available 45 nm RF-CMOS process. The design is based on a well known RC bridge topology which was optimized for maximum phase shift and minimal amplitude response variation versus phase and frequency. Phase is controlled by varying DC voltage on a varactor, resulting in 60º maximum phase shift with 0.1 dB amplitude variation at 24GHz. The size of the phase shifter circuit excluding pads and input/output buffers is 40×50 µm2.