Analysis of Electromagnetic Nearfield Disturbances on Printed Circuit Board and IC Level

现代电子系统的数据传输速度和封装密度不断提高。此外，还降低了信号和电源电压电平，以降低功耗。这导致了较小的信噪比和对电磁干扰的日益敏感。被测设备(DUT)的电磁敏感性通常在天线的远场中进行，例如在半电波暗室中。在DUT未通过测试的情况下，可以获得关于干扰场的相应频率和幅度的信息。然而，关键耦合路径和敏感元件的局部化通常并不明显。对于这种故障诊断，特别是在印刷电路板(PCB)上，建议使用小型电磁探头的近场扫描作为一种补充测试方法。然而，目前还没有比较近场和远场测量结果的系统方法。因此，研究请求的目的是扩展和推广运行项目的基本结果。近场和远场干扰之间的定量关系应该用与输入传输线的耦合电压有关的相关系数来表示。已发展的电小探头解析关系应扩展到较大的(谐振)天线探头。将关注相对于传输线的波极化以及线路端接的影响。为了验证模型的有效性，设计了更接近实际的数值模拟和测量配置。为此，干扰不应仅限于纯CW信号或梯形脉冲。还应该使用例如在移动通信系统或WLAN网络中使用的更真实的调制信号。必须找到、建造和测试合适的天线几何形状。干扰影响将根据数字数据传输线的误码率(BER)来衡量。

The data transmission speed and packaging density of modern electronic systems are continuously increasing. Furthermore signal and supply voltage levels are reduced to decrease power dissipation. This results in a small signal-to-noise ratio and an increasing sensitivity against electromagnetic interference. The electromagnetic susceptibility of a device under test (DUT) is usually conducted in the far field of an antenna, as for example in a semi anechoic chamber. In cases where the DUT fails the test, information about the corresponding frequency and amplitude of the interference field is available. However, the localization of the critical coupling path and the sensitive components is usually not obvious. For such fault diagnostics especially on printed circuit boards (PCB) near-field scanning using small electric or magnetic probes has been suggested as a complementary test method. However, a systematic method for comparing near- and far field measurement results is not available so far. For this reason the aim of the research request is to expand and generalize the fundamental results from the running project. The quantitative relationship between near- and far field disturbances should be expressed in terms of a correlation factor, concerning the coupled voltage into a transmission line. The already developped analytic relation for electrically small probes should be expanded to bigger (resonant) antenna probes. Attention will be paid on the wave polarization relative to the transmission line as well as the influence of the line terminations. To validate the model, numerical field simulations and measurement configurations close to reality are intended. For this purpose the disturbance should not be restricted to pure CW signals or trapezoidal pulses. Also more realistic modulated signals, as used for example in mobile communication systems or WLAN networks should be employed. Suitable antenna geometries have to be found, constructed and tested. The disturbance influence will be measured in terms of the bit error ratio (BER) of a digital data transmission line.