Multi-phase ring oscillator with minimized phase noise for ultra-wideband applications

This paper presents the design of a simple multiphase ring oscillator (RO). It represents a new technique for RO output signal phase control. This RO uses a voltage injection principle to produce different phases output signal. The proposed RO consumes only 3.6 mW from a 1.8V power supply while having an oscillation frequency of 5.5 GHz with a 330 MHz fine tuning range. This RO is employing the pulse injection technique for phase noise enhancement. It has a phase noise less than −133.5 dBc/Hz @ 1 MHz offset. It achieves a figure of merit (FoM) of −182.75 dBc/Hz. This RO is designed and simulated in the standard 0.18 μm CMOS technology.