A Quadrature Oscillator with a Frequency-Tuned Distributed RC Network Analysis

This paper introduces an innovative two-stage distributed RC oscillator design, enhancing the noise performance and frequency stability for compact electronic devices. This work significantly reduces the comparator noise and improves system reliability by implementing a novel approach to increase the signal transition slope, coupled with optimized resistor and capacitor configurations. The study employs a quadrature oscillator topology and a precise reference voltage generation method, effectively addressing the challenges of mismatch and noise performance. A 469.2 kHz quadrature oscillator with two-stage distributed RC is implemented with a 0.18 μm CMOS process, achieving a FoM of −160 dBc/Hz at 100 Hz with a stable −20 dB roll-off in the phase noise and an Allan deviation floor of less than 0.7 ppm.