A Square-Law Circuit
J H P Draper, David Gorda Tucker · Journal of Scientific Instruments · 1947
A method is described of obtaining a voltage which is proportional at any instant to the square of a given voltage, without using filters. The given voltage is applied at a low level across a rectifier in series with which is a small resistance. A voltage taken off across this resistance has connected to it in series-opposition a voltage which is a suitable proportion of the applied voltage. The resultant is shown to be almost exactly proportional to the square of that given. The theory and practical considerations are discussed; some results are quoted.