Technological scaling and minimization of 1/f noise in SiGe HBTs coupled mode N-Push oscillator/VCO

Abstract

This paper discusses the impact of technological scaling and minimization of flicker (1/f) noise on SiGe HBTs in coupled mode N-push oscillator/VCO configuration, which has recently emerged as a strong contender for RF and mixed- signal applications. 1/f noise in SiGe HBTs is sensitive with device scaling and significantly up- converted in coupled mode oscillators due to the presence of asymmetrical output from their subsequent N oscillator sub-circuits that forms N-push configuration. Improving the symmetry of the coupled mode N-Push topology develops a method of minimizing the 1/f noise up-conversion and phase noise in the scaled device. The experimental result shows 12 dB improvement in the noise performances for a typical symmetrical coupled mode VCO at 10 kHz offset from the carrier frequency 8000 MHz in comparison to the asymmetrical version of the coupled mode scaled device (SiGe HBTs).