Title :
PM and AM noise in nonlinear BJT amplifier
Author_Institution :
Power Eng. Inst., Moscow, Russia
Abstract :
An approach to nonlinear BJT amplifier PM and AM noise calculation is presented. Polyharmonic presentation of voltages and currents is used and periodical nonstationarity of BJT noise sources due to their modulation by periodic signal is taken into consideration. Due to these effects one has to introduce different “noise factors” for PM and AM noise calculation (if one expands the formulae obtained for linear mode of operation to nonlinear one), and these noise factors depend on the input signal level. Common emitter (CE) amplifier with both bypassed and unbypassed resistors in emitter circuit is considered in detail. Power spectral densities of AM and PM noise are calculated as functions of signal amplitude. An influence of bypassed and unbypassed emitter resistor on PM and AM noise is investigated
Keywords :
amplifiers; bipolar transistor circuits; circuit noise; nonlinear network analysis; AM noise; BJT noise sources; PM noise; bypassed resistors; input signal level; nonlinear BJT amplifier; periodical nonstationarity; polyharmonic presentation; power spectral densities; unbypassed resistors; Broadband amplifiers; Circuit noise; Feedback circuits; Impedance; Low-frequency noise; Noise level; Power amplifiers; Resistors; Voltage; Wideband;
Conference_Titel :
Frequency and Time Forum, 1999 and the IEEE International Frequency Control Symposium, 1999., Proceedings of the 1999 Joint Meeting of the European
Conference_Location :
Besancon
Print_ISBN :
0-7803-5400-1
DOI :
10.1109/FREQ.1999.841551
