Evaluation of radiated immunity tests using adjusted pulse modulated signals

Abstract

The main goals of an engineering test are reproducing a real scenario in a controlled environment and monitoring a device under validation when exposed to such condition. In this context, some recent studies have indicated misalignments between the waveforms suggested by the Radiated Immunity standards and the real telecommunication signals. Reproducing an actual signal in an electromagnetic compatibility laboratory might, however, be an expensive task, since it demands more sophisticated hardware. In this study, a simple solution for this problem is proposed based on adjustments applied to the standardised pulse modulated waveform. The objective is to develop an alternative to the traditional procedures, in an attempt to provide the manufacturers a more realistic test environment for their products. Mathematical manipulations indicate that a good agreement between the adjusted waveforms and a digital television signal cannot be simultaneously achieved in both time and frequency domains. Multiple trade-off solutions are then generated and analysed through electromagnetic simulations. Results show that, in the 210-216 MHz frequency range, the pulse modulated signals model the digital television interference capability better than the classical continuous wave does.