A model for phase noise generation in amplifiers

Abstract

In this paper, a model is presented for predicting the phase modulation (PM) and amplitude modulation (AM) noise in bipolar junction transistor (BJT) amplifiers. The model correctly predicts the dependence of phase noise on the signal frequency (at a particular carrier offset frequency), explains the noise shaping of the phase noise about the signal frequency, and shows the functional dependence on the transistor parameters and the circuit parameters. Experimental studies on common emitter (CE) amplifiers have been used to validate the PM noise model at carrier frequencies between 10 and 100 MHz.

The noise conversion method for oscillatory systems

“…3 shows what happens if the reactance's flicker noise is assumed to be negligible, α X = 0. With zero flicker coefficient of losses (a), the amplitude PSD is only 7 There had been a discussion in the literature about the actual phase PSD's slope of the crystal resonator beyond the half bandwidth (see a brief review in [8]). Some authors had brought forward evidence for near f −2 , and others had shown the measurement with almost f −3 .…”