RF CMOS LC-oscillator with source damping resistors

Abstract

This letter proposes a new method to suppress the 1/f noise contribution of active devices in an oscillator using source damping resistors. The operational mechanism of the proposed source damping resistor method is analyzed through circuit simulation with a complementary LC-oscillator. The reduced 1/f noise leads to the phase noise improvement by suppressing 1/f noise up-conversion to phase noise. The measurement result shows that there is about 6.0 dBc and 4.0 dBc of phase noise improvement at 10 kHz and 100 kHz offset frequency with differential complementary LC-oscillator topology, respectively.