Residual phase noise modelling of amplifiers using silicon bipolar transistors

This paper describes the modelling of residual 1/f phase noise for Si bipolar amplifiers operating in the linear region. We propose that for Si bipolar amplifiers the 1/f phase noise is largely due to the base emitter recombination flicker noise. The up conversion mechanism is described through linear approximation of the phase variation of the amplifier phase response by the variation of the device parameters (C_bc, C_be, g_m, r_e) caused by the recombination 1/f noise. The amplifier phase response describes the device over the whole frequency range of operation where the influence of the poles and zeros is investigated. It is found that for a common emitter amplifier it is sufficient to only incorporate the effect of the device poles to describe the phase noise behaviour over most of its operational frequency range. Simulations appear to more accurately predict the measurements of others.