| With the rapid development of electronic technology and increasingly complex electromagnetic environment, electronic product design is facing with the demand of miniaturization and multifunction. One of the basic electronic product design is printed circuit board,which faced with electromagnetic interference issues caused by electromagnetic environment of external device-level and poor system-level,signal integrity issues caused by board-level interconnection lines,power integrity issues caused by current changes of the power and ground. In this paper, based on the need of hardware system design of Remote Monitoring System under complex electromagnetic environment, the signal integrity of hardware circuit design, the power integrity and the relevant theory of electromagnetic compatibility were investigated. Meanwhile,the electromagnetic co-simulation design method was proposed, and the results of co-simulation analysis and the actual test were combined to verify the effectiveness of electromagnetic co-simulation analysis in circuit design. In this article,the theory of co-design is throughout the project, the standardization of the design rules were used in remote monitoring systems under complex electromagnetic environments. The main results are as follows:In this paper, from the angles of theory and simulation, based on the essence of the signal of time domain and frequency domain, the signal integrity analysis methods were introduced in detail. In power integrity analysis, the causes of power integrity were analyzed. The main factors that influence the EMC/EMI were analyzed, and the system EMC performance was improved from the perspective of signal flow and segmentation. According to the characteristics of the above three parts, the electromagnetic co-simulation analysis method was proposed, and this method regulated the basic steps and procedures of electricity, magnetic simulation.According to the project requirements, the hardware circuit schematic diagram of the remote monitoring system under complex electromagnetic environment was designed. The layout and wiring of the printed circuit board were performed based on the basic steps and processes of electrical, magnetic simulation.Feasibility of initial layout was verified before the simulation analysis of the circuit board,.After the simulation of signal integrity analysis, the S-parameter model for the signal line of key modules such as GPRS module and USB interface were analyzed., and the signal quality of each signal line were evaluated based on the extracted parameters model. In the section of power integrity simulation analysis, the impedance characteristics between power and ground planes were analyzed to verify the feasibility of power integrity design. In the section of electromagnetic compatibility simulation analysis, the simulation analysis by near-field and far-field were analyzed to evaluate the the area with larger signal ratiation on the PCB board. The layout and wiring of the PCB should make the devices, which are sensitive to noise or signal traces, to avoid the area with larger radiation so as to guarantee the good EMC performance of the system.Based on the results of simulation analysis, the test platform hardware system was built. The time-domain waveform of the key signal were tested, and the signal of the key link didn’t show obvious reflection, crosstalk, overshoot, undershoot and other issues that affect signal integrity; each IC supply terminal has a smaller ripple voltage, and each IC works stably;through the electromagnetic ripple probed by the carpet on the PCB, a small electromagnetic noise on the entire PCB was found. Through the testing of the simulation analysis, the remote monitoring system under complex environments was verified to meet the signal integrity, power integrity and electromagnetic compatibility design, and the feasibility and effectiveness.of electromagnetic co-simulation analysis method used in the hardware system design under complex environment were also verified. |
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