基于MATLAB建模的电磁兼容测试中接收机数字化设计

Digital Design of Electromagnetic Compatibility Test Receiver Based on MATLAB Modeling

随着虚拟仪器的快速发展,对如何将虚拟仪器的可定制性、易扩展、价格低廉等优势应用于电磁兼容测试的接收机进行了研究。通过让数字化虚拟仪器部分取代乃至完全取代传统仪器,已成为日后电磁兼容技术革新的关注焦点。基于MATLAB软件搭建了接收机的模型,实现了接收机的数字化设计。其中中频滤波器的滤波窗函数采用高斯函数,带宽通过修正系数拟合;检波器经过傅里叶变换,实现信号的频谱计算以及包络线绘制。模型通过频选信号的变化,能够实现峰值和平均值两种检波效果。实际测试结果与模型仿真结果误差小于10%,符合企业测试要求。该模型具有较强的扩展性与兼容性,能对整车与高低压零部件的电磁兼容问题进行一定的监测,设计经验对后续电磁兼容测试过程整体数字化发展有着重要意义。

With the rapid development of virtual instruments,this paper studies how to apply the advantages of customization,scalability and low cost of virtual instruments to the receiver of electromagnetic compatibility testing.By partially or even completely replacing traditional instruments with digital virtual instruments,it has become the focus of future electromagnetic compatibility technology innovation.A receiver model is built based on MATLAB software,and the digital design of the receiver is realized.The filter window function of the IF filter adopts Gaussian function,and the bandwidth is fitted by the correction coefficient.The geophone is transformed by Fourier transform to realize the spectrum calculation and envelope drawing of the signal.The model can achieve peak and average detection effects through the change of frequency selection signal.The error between the actual test results and the model simulation results is less than 10%,which meets the testing requirements of enterprises.The model has strong scalability and compatibility,and can monitor the electromagnetic compatibility problems of the whole vehicle and high and low voltage parts to a certain extent.The design experience is of great significance for the overall digital development of the subsequent electromagnetic compatibility testing process.