通信设备辐射发射超标的案例分析及对策

Case Analysis and Countermeasures of Radiation Emission Exceeding Standard of Digital Trunking Communication Equipment

通过分析某型号通信设备辐射发射超标问题,论述辐射发射超标问题的故障定位思路及其方法。依据EMC三要素,采用了产品辐射发射线缆定位过程,对问题进行详细的定位,最终发现了其内部时钟信号的谐波频率沿其电源线向外辐射的现象,通过调整时钟驱动器芯片向其SDRAM输入路径上的电阻数值来降低产品对外的辐射骚扰发射,使得产品通过了杂散发射限值的要求,避免采用了在电源线上增加磁环等传统的整改方法,不仅提高了产品的EMC质量,同时也降低了产品的故障解决成本。

By analyzing the problem of radiation emission exceeding the standard of digital trunking communication equipment,this paper discusses the idea and method of fault location of radiation emission exceeding standard.According to the three elements of EMC,the product radiated emission cable positioning process was adopted,and the problem was analyzed in detail.Finally,it was found that the harmonic frequency of the internal clock signal radiated outward along the power line.By adjusting the resistance value on the input path of the clock driver chip to its SDRAM,the external radiation disturbance emission of the product was reduced,and the product passed the stray emission limit The traditional rectification methods such as adding magnetic ring on the power line are avoided,which not only improves the EMC quality of the product,but also reduces the cost of troubleshooting.