Innovative pre-compliance test methodology using ambient cancellation and coherence detection techniques

An innovative pre-compliance test methodology is introduced which enables accurate and rapid radiation emission testing in the presence of strong interfering ambient radiators. The methodology is based on a test technique which uses time and frequency synchronized multi-channel receiver systems to simultaneously record total fields at multiple locations. Advanced signal processing is used to cancel interfering ambient signals, accurately estimate the EUT signal strengths, and relate radiation emission signals to their origins. The presented test methodology virtually eliminates the need for expensive anechoic chambers for pre-compliance testing and EMI troubleshooting. As a result, low cost and automated pre-compliance testing can be effectively conducted in open area test sites (OATS) or inside fully operational plants throughout the product development cycle.