Guidelines for Designing BJT Amplifiers with Low 1/f AM and PM Noise

Eva S. Ferre-Pikal, Fred L. Walls, and Craig W. Nelson

ABSTRACT In this paper we discuss guidelines for designing linear bipolar junction transistor amplifiers with low 1/f amplitude modulation (AM) and phase modulation (PM) noise. These guidelines are derived from a new theory that relates AM and PM noise to transconductance fluctuations, junction capacitance fluctuations, and circuit architecture. We analyze the noise equations of each process for a common emitter (CE) amplifier and use the results to suggest amplifier designs that minimize the 1/f noise while providing other required attributes such as high gain. Although we use a CE amplifier as an example, the procedure applies to other configurations as well. Experimental noise results for several amplifier configurations are presented.

1997 IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 44:335-343

© 1997, by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.

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