Two New Electronic Analog Multipliers

Abstract

This paper describes two new four‐quadrant analog multipliers which have some advantages over other designs which have been reported earlier. A satisfactory balanced modulator which is necessary for both designs is described in some detail. The first multiplier uses a modified double amplitude modulation scheme applying the recent work of Sternberg and Kaufman on the two‐frequency modulation product problem. The test multiplier has a frequency response from dc to 30 kc for either input. The accuracy is ±0.5 percent of full scale at full‐scale output, and ±0.2 percent of full scale at one‐tenth of full‐scale output. The dc drift stability of the output is ±0.15 percent of full scale, and the scale factor stability is ±1 percent of full scale over a period of several hours. The second multiplier uses successive phase modulation and amplitude modulation of a carrier. A description of the method and a discussion of error sources are given. The performance of this multiplier is in general inferior to that of the first.