CMOS Open-Loop Local Quadrature Phase Generator for 5G Applications

An open-loop feedback-less CMOS quadrature (I/Q) local oscillator (LO) signal generator is presented. The circuit generates differential 90° shifted LO outputs from a differential input LO at the very same frequency. The phase accuracy of the implemented circuit relies on the matching of two delays and linear phase interpolation. The presented circuit is designed in a 28 nm bulk-CMOS technology implemented without any passive components covering an operating frequency range from 5 GHz up to 6 GHz. Simulation results of the designed I/Q generator show a worst case phase noise performance of –151.3 dBc/Hz at 100 MHz offset with a worst case power consumption of only 3.4 mW from a 0.95 V supply.