IC design: Emitter degeneration effects in common emitter amplifiers

A technique used in the design of common emitter amplifiers, both to increase input impedance and bandwidth, is emitter degeneration. This consists of inserting an unbypassed series resistor from the emitter of the bipolar to a common point ( ground, virtual ground, etc.) The impact of this method on the circuit performance is explored in a recent brief publication by Signal Processing Group Inc. The paper may be found at http://www.signalpro.biz>Engineer's corner.