Semiconductor device and noise sources modeling: design methods and tools oriented to nonlinear H.F. oscillator CAD

Abstract

Designing oscillator circuits at RF and microwaves requires specific knowledge in extremely varied fields of electronics. The following items will be the core of the presentation: - The physical processes leading to low-frequency noise in semi-conductor devices and the nonlinear behavior of the noise sources in large signal operating conditions will be detailed - Transistor modeling: A special emphasis will be put on the low-frequency noise modeling associated to the nonlinear transistor models. - Simulations tools: In order to simulate accurately the phase noise in free-running nonlinear oscillator circuits, the frequency domain approach based on the conversion matrices formalism which is related to the harmonic balance formalism will be detailed. - Design rules for low phase noise operation Theoretical conditions to be fulfilled by the circuit will be detailed on the basis of the Leeson analysis revisited. The need of new characterizations and extraction methods of noise sources in actual transistors, for a better prediction of noise performances of nonlinear circuits will be recalled.