A miniaturized very low-power vector modulated CMOS phase shifter for wireless receivers

This paper presents and analyses a phase shifter for diversity receivers, which modulates the I-/Q-vector in the constellation diagram. The system consists of a three stage programmable gain amplifier (PGA) chain in both branches. The design covers the full phase range of 360°. Each stage can be programmed to amplify the incoming signal between 19 dB and 63 dB with a centre frequency of 3 MHz. The radio frequency (RF) signal is down-converted to an intermediate frequency (IF) of 5 MHz, where phase shifting is done. The circuit is intended for an automotive satellite radio receiver in S-and L-band. Thus, demand automotive requirements have to be fulfilled. The supply voltage is 1.8V. Compared to other phase shifters, the power consumption of 2.7mW is highly energy-efficient. This system includes a constant gm-source and a biasing circuit. All requirements are verified in post-layout Corner and Monte-Carlo analysis using Virtuoso and WiCkeD. The design only takes 0.116mm² of silicon area in a 150- nm CMOS technology.