Applied research of EMR Virtual Chamber measurement system

In order to expand the application range of the EMR (Electro Magnetic Radiation) Virtual Chamber measurement system and improve the measurement precision in actual measurement, a mathematical method of adaptive filtering and wiener filtering is used to analyze the inherent defects of the measurement system based on traditional ANS (Automatic Noise Suppression), and the thesis point out that the main factor which restricted the application range and measurement precision is the existence of source signal component which is detected in the reference channel. According to the analysis result, the measurement system is rebuilt, coming up an ANS based on spectral estimation. Analyzing the mixed signal detected in the main channel, the remodelled system can get the PSD (power spectrum density) of radiation signal and noise signal. According to the frequency of the peak point in the PSD, notch filter has been designed to filter out the radiation signal component captured by reference channel, then the system meets its expectation. The simulation results indicate the good performance of the method in the high SNR (signal noise ratio) measurement circumstance as well as low SNR.