An LO Phase Shifter with Frequency Tripling and Phase Detection in 28nm FD-SOI CMOS for mm-Wave 5G Transceivers

Abstract This paper presents an LO generation circuit for 28-GHz 5G transceivers. It features phase shifting and frequency tripling using an injection-locked oscillator and injection-locked frequency tripler, respectively. A phase detector based on third harmonic mixing is also implemented and is used to detect the applied phase shift, supporting automatic calibration of the phase shifter. Additionally, an algorithm to automatically tune the oscillators to their respective locking frequency is presented. To test the LO circuitry, a 24-30-GHz sliding-IF receiver is implemented. Simulations show that a >360o tuning range over the full 24-30 GHz span is achieved, with a gain variation of 0.11 dB or less, and that the phase detector has an rms phase error of <2.5o. The circuit is implemented in a 28nm FD-SOI CMOS process and the entire chip measures 1080µm x 1080µm, including pads, and consumes 27-29 mW from a 1 V supply.