A Low Phase Noise Class-C Oscillator Using an Improved Resonator

In this paper, a low phase noise class-C oscillator is presented. The phase noise reduction is achieved by using an improved resonator instead of conventional parallel LC resonator. Moreover, compared to the conventional class-C oscillators, the start-up problem is compromised and consequently, the oscillation amplitude is also increased. The proposed class-C oscillator is simulated in 0.18 μm CMOS technology. The simulated phase noise is −134.2 dBc/Hz at 1 MHz offset frequency. The oscillation frequency and the power consumption of the oscillator are 2.7 GHz and 26.8 mW, respectively.