THE MEASUREMENT OF IMPEDANCE AT HIGH POWER,

A method and the electronic equipment for applying it was developed to enable the impedance of a transducer or other device, linear or nonlinear, to be calculated from measurements made while the device is operating at high power, pulsed or c-w. The method involves the use of a null-balance technique by which the current and voltage of a c-w reference signal are compared with samples of the unknown signal and nulled against the unknown on an oscilloscope. The relative phase also is measured. Toroidal transformers provide the means of extracting samples from the high driving voltage and current. The electronic components are of solid-state circuitry throughout. Author