Research On The Signal Transmission Performance Of Electronic Devices Based On Electromagnetic Compatibility

Electromagnetic compatibility is an important part in the performance testing of electronic equipment.It refers to the ability of the internal devices of electronic equipment to work without emitting unbearable interference to the environment and to work normally without reducing performance in the case of external electromagnetic interference.With the development trend of miniaturisation of electronic equipment,high-speed digital circuits and complex external electromagnetic environment,the problem of electromagnetic compatibility in electronic equipment is becoming more and more prominent.For the study of the signal transmission performance of electronic equipment,there is a complex field-circuit synergy.Therefore,the relevant researches on the electromagnetic interference in the process of signal transmission and the external electromagnetic radiation caused by signal transmission of electronic devices are studied by field-circuit co-simulation in this paper.In this paper,the field-circuit co-simulation platform of signal integrity analysis is established based on the cache module firstly.Through this platform,PCB with a chip IBIS model can be simulated for signal transmission performance to investigate the signal reflection and crosstalk problems,and to propose improvement solutions.The results show that for the reflection problem of the cache module address line ADDR10 can be effectively solved by serial termination of 30Ωwithout affecting the signal transmission peak.Meanwhile,both near-field and far-field radiation field analysis show that the improvement in signal integrity contributes to the overall reduction in external radiation levels.Then an antenna-signal line EMI model is constructed to simulate the EMI between the signal line and the antenna.The effect of signal line/antenna radiated emissions on the antenna reception function and the effect of antenna radiated emissions on the signal transmission are obtained through field-circuit co-simulation.The results show that the signal rise and fall times have a very significant effect on the EMI level.The EMI from antenna radiated emission on signal transmission is mainly related to the distance between them,and the distance between the signal line and the board edge is also an influencing factor.Simulation results of the antenna radiation emission on the signal transmission waveform in the time domain show that a radiation interference of around 20W/m~2 can already make visible changes in the signal waveform.Finally,the discharge waveform of the electrostatic generator is improved based on the electrostatic generator circuit model and the full-wave model.Then the improved electrostatic generator model is used to investigate the effection of electrostatic discharge on mobile phone and antenna-microstrip line coupled systems.The results show that the 8k V electrostatic discharge produces large oscillations in the signal transmission waveform in the antenna-microstrip line coupled system,and the coupling voltage in the antenna can reach up to 2.8V.In mobile phone electronic equipment,the interference of electrostatic discharge on signal waveform can be effectively reduced by adding metal shielding layer.In this paper,electromagnetic interference and external electromagnetic radiation during signal transmission of electronic devices are studied by field-circuit co-simulation method.It provides theoretical guidance for improving the electromagnetic compatibility performance of electronic devices in the product design process.