Title :
PM and AM noise in voltage controlled phase shifters
Author :
Kuleshov, V.N. ; Mordvinov, A.E.
Author_Institution :
Moscow Power Eng. Inst. (Tech. Univ.), Moscow
Abstract :
PM and AM noise analysis in voltage controlled phase shifter, consisting of two amplifiers with voltage controlled gain, phase splitter and summing amplifier, is presented. It is based on the theory of PM and AM noise in bipolar junction transistor (BJT) amplifiers. Both 1/f and wideband noise sources in BJT amplifiers are taken into consideration. It is shown that conversion of AM noises of the amplifiers with voltage controlled gain to PM noise of the phase shifter gives the main contribution to total 1/f PM noise. The formulae for power spectral densities of PM and AM noises are obtained. An influence of feedback through unbypassed and bypassed emitter resistances in the voltage controlled amplifiers on the phase shift control characteristic and PM noise is investigated. Opportunities to decrease PM noise using this feedback are analyzed and discussed. An examples of PM noise calculation are considered.
Keywords :
amplifiers; amplitude modulation; bipolar transistors; noise; phase modulation; phase shifters; AM noise; BJT amplifiers; PM noise; bipolar junction transistor amplifiers; bypassed emitter resistances; phase splitter; power spectral densities; summing amplifier; unbypassed emitter resistances; voltage controlled gain; voltage controlled phase shifters; wideband noise sources; 1/f noise sources; PM and AM noise; phase control characteristic; voltage controlled phase shifters; wideband noise sources;
Conference_Titel :
Frequency and Time Forum, 2004. EFTF 2004. 18th European
Conference_Location :
Guildford
Print_ISBN :
0-86341-384-6
