Design criteria for BJT amplifiers with low 1/f AM and PM noise

Description

This item was taken from the IEEE Periodical ' Design criteria for BJT amplifiers with low 1/f AM and PM noise ' In this paper we discuss guidelines for designing linear bipolar junction transistor (BJT) 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.