Low Power Linear Circuits

The importance of low power linear circuits in portable military communications and surveillance equipment has been expanding continually in recent years. Using optimum design techniques, the quiescent power requirements of many of these circuits-including low-frequency, wide-band, tuned, and low-noise amplifiers as well as oscillators, mixers, and detectors--frequently can be reduced by more than an order of magnitude compared with current practice. Three principal features of these optimum design techniques are: 1) the use of transistors whose maximum frequency capabilities are well beyond the range of direct interest for the circuit under consideration, 2) the selection of circuit configurations which demonstrate superior low power performance, and 3) the description of the quiescent power requirements of each circuit in terms of its primary small signal design constraints. Salient features of an FM helmet radio receiver designed for minimum power drain illustrate the optimum design techniques.