The Equivalent Current Measurement Technique and its Comparison with Current Probe Methods

An equivalent current measurement technique is presented which has advantages over conventional probe methods. The technique has been successfully implemented in internal microwave coupling experiments at the Lawrence Livermore National Laboratory (LLNL) time domain range. Currents have been measured for short-circuit terminations at the bases of cables inside cavities with apertures illuminated by incident waves. Results have been obtained at frequencies much higher than the upper limit of the best commercially available current probes. A theoretical development of the technique and a description of its experimental implementation are given. Representative results and their comparison with those taken with a commercially manufactured current probe are also presented.