Electromagnetic Compatibility Research And Application

Electromagnetic compatibility is an emerging comprehensive subject, its elementary knowledge is extremely widespread, mainly includes theory of electromagnetic field, principles of electronic engineering, electronic technology, electromagnetism survey, signal analyzing, mechanism, automatic control, biomedicine, material and craft and so on, electromagnetic compatibility is very overlapping and complex subject.EMC is a capability that the device can work regularly in electromagnetic environment, and also is a technology approach used to improve product reliability. The electronic products easily infiltrate into international markets with good EMC.In actual electronic products system, as the digital signal frequency is more and more high, PCB not only is a braced structure of electronic system, moreover may be a system structure with EMI problem. In order to make the electronic products to satisfy the EMC request, the design principle and the method of electromagnetic compatibility of PCB must be studied. The contents include: conductive coupling and radiative effect of PCB interconnection line in high frequency status; noise signal collected by the PCB electric circuit wire or the circuit loop etc.In order to realizing the electromagnetic compatibility design request, software anti-jamming must be considered in the MCU circuit system, besides considering hardware anti-jamming of circuitry and PCB layout. The software anti-jamming technology has the merits of the high reliability and easily-revised, the noise enters from any position can be overcome with digital filtering. The software anti-jamming may reduce the design cost of system, and also affords an advantageous supplement for the hardware anti-jamming.In this paper, the development history of the electromagnetic compatibility technology and the technical survey are elaborated, the electromagnetic compatibility elementary theories such as the transmission line theory and the electromagnetic interference mechanism and so on are studied, and also the hardware and software electromagnetic compatibility design essential method of electronic system are elaborated. Electromagnetic compatibility and the electromagnetic interference and so on are elaborated used an example of electromagnetic compatibility of intelligent battery charger, the analysis to mechanism of the conducted electromagnetic interference and the radiated electromagnetic interference is carried on, and the basic theoretical calculation formula is inferred. Meanwhile the detail solutions to two these kinds of interference are proposed and the theory of realizing product electromagnetic compatibility is put forward.