Comparative study of phase and amplitude noise of CE, CE-CB and CC-CB bipolar transistor amplifiers

Results of development of an algorithm for theoretical calculations both wideband and 1/f PM and AM noise in common emitter (CE), common emitter-common base (CE-CB) and common collector-common base (CC-CB) amplifiers are presented. The algorithm is based on using hybrid pi model of a bipolar junction transistor (BJT). An influence of wideband noise sources is calculated basing on well known noise model of a BJT. An influence of 1/f noise sources is calculated using a model with fluctuating recombination conductance presented in the paper. Using the algorithm and results of measurements of 1/f current noise of BJT, power spectral densities of wideband and 1/f PM and AM noise of CE, CE-CB and CC-CB amplifiers with complex emitter impedance Z/sub E/ were calculated. Basing on these calculations a comparison of CE, CE-CB and CC-CB amplifiers is presented. The values that are compared are power spectral densities of PM and AM noise. The opportunities of 1/f PM noise compression by specially selected parameters of emitter impedances are investigated. Some recommendations for design of low PM and AM noise amplifiers are presented.