Study On The Generation Of Electromagnetic Environment Signals

With science and technology developing rapidly, the electromagnetic environment signal is getting more and more diversified, and the bandwidth of the spectrum of the electromagnetic environment signal is getting more and more widely. The variety of the electromagnetic environment signal is embodied on the variety of modulation signal, the variety of modulation type and the variety of modulation parameter. Precondition of evaluating the EMC performance of the electronic equipment is to simulate and generate variety signals.At present, the primary way to generate signals under laboratory condition is using signal simulator such as function generator, vector signal generator and so on. There are two kinds of method to realize the above way. One is to adjust the simulator manually, another is to adjust the simulator by program control. In fact, program control combined with the computer interface is the main way to realize the automatic measure and test.Based on the arbitrary wave generator, this paper proposes using the IQ modulation combined with the external modulator to generate electromagnetic environment signals. With the communication signals as the main analytic objects, this paper analyses the IQ decomposition of the typical communication signals, include analog communication signals and digital communication signals. This paper also study and analyses the effects of the baseband pulse shaping filter, the band pass filter and the fading channel on the transmitted signal. The relevant mathematical models given in this paper provide the basis for the generation of the signals.At last, on the basis of the above study work, the overall software architecture and the relevant design method of the database is given. The software and the database is designed on the design basis.The primary study achievements are as following:(1) The IQ decomposition of typical communication signals is deduced as mathematical models for the generation of the signals through the IQ modulation.(2) The effects during the generation and transmission in practical situation is discussed, and provides mathematical models to modify the ideal I\Q data.(3) The signal generation software and relevant database are made as the software base of electromagnetic environment signal generation technology.