Time Domain Measurements a novel method for qualification of electronics

Time Domain Measurements are a new analysis tool to extract transient and time limited disturbing RF signals hidden in the emission spectrum of modern electronic devices. Examples of complex emission spectrums are electronic modules or components used in automotive applications, or any microprocessor, buss controlled systems of household appliances or power electronics regulating systems. Other areas of interest are RF transmitting and receiving devices using digital modulations schemas (LTE, UMTS, WCDMA, GSM, WLAN, Bluetooth). Further challenges for repeatable EMI measurements are frequency hopping technologies to improve transmission quality used in mobile applications. New Digital Broadcasting Systems (DVB-T, DVB-T2, DAB, DAB+) create additional RF interference scenarios for stationary and mobile receiver applications. The typical radiating power of such transmitters, are by a magnitude of 2 smaller that the predecessor analogue transmitting stations. Such signals and possible interferences with other electronic systems are often characterised as short term events with transient nature. The use of WLAN and other wireless services in the area of home applications are further areas of interest. Some home appliances interfere with wireless communication and need further investigation. Especially critical areas are disturbances which are not continuous, but directly connected to the state of operation. To capture such time limited RF signals and to perform reproducible measurements is difficult. Today such measurements can be done using time domain measurement technology. Those measurement systems are equipped with several very fast A/D converters, RF preselection, automatic RF attenuator used for EMI receiver and very powerful FPGA's (Field Programmable Gate Areas) to calculate several thousand frequency points, several Detectors, IF filters in parallel.