Calibration of current measurement transducers in oversized calibration fixtures

A simple one-dimensional (1D) transmission line model has previously been used to derive improved estimates for the transfer impedance of current transducers at high frequencies by taking account of the finite reflections that occur at the ports of the calibration fixture. This approach is further extended to take account of the additional reflections that occur in the system when an oversized calibration fixture is used. The success of this method is also assessed, for frequencies up to 600 MHz, using measured and computed results for the current induced on a wire inside a cavity backed aperture illuminated by a nearby antenna.