Temperature Sensitivity of Non-Degenerate Modes in CMOS LC Quadrature Oscillators

This brief studies the frequency drift due to temperature variation in
LC
CMOS quadrature oscillators. The quadrature oscillators, which can oscillate in two modes at different frequencies, have different temperature behavior in the two modes, with one mode showing lower sensitivity to temperature variation. Simulation results of a series coupled quadrature oscillator confirm that the mode with higher frequency is more stable to temperature variation. The measurement results of the fabricated chip in a 90-nm CMOS technology verifies the analysis. The optimized frequency drift is ±100 ppm across temperature (0-60°C) for an oscillation frequency of 5 GHz with -118 dBc/Hz phase noise at 1 MHz offset frequency while consuming 8 mA from a power supply of 1.2 V.