An Application of the Subwavelength Periodic Microstrip Guard Trace in High-Speed Circuits
An Application of the Subwavelength Periodic Microstrip Guard Trace in High-Speed Circuits
复制标题
亚波长周期性微带保护走线在高速电路中的应用
DOI：
10.1109/access.2022.3168679
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发表时间：
2022-01-01
期刊：
影响因子：
3.9
通讯作者：
He, Fang
中科院分区：
文献类型：
--
作者：
Wu, Chia Ho;Ma, Peixun;He, Fang
提出了一种基于亚波长周期结构的保护走线，以降低PCB中平行微带线的远端串扰。该技术可用于改善多导体传输线电路系统的误触发和信号传输能力。为了探讨新型防护线隔离电磁干扰的效果，给出了整个电路系统的互电容和互感的频率响应，并建立了等效电路模型。与传统的微带线隔离平行微带线之间的电磁干扰相比，新型的保护走线可以有效地减少整个电路系统的互电容和互感。因此，这有利于抑制微带线之间的串扰。S参数计算结果表明，这种亚波长周期微带保护线能更有效地隔离微带线间的电磁干扰。特别是，传统的接地保护迹线需要大量密集的接地孔，这严重影响了多层电路板的各层布线设计。然而，所提出的保护迹线仅需要一个接地孔，这对多层印刷电路板的每一层的电路布线影响很小。在实验中，将上升时间为30 ps的阶跃函数信号输入到一条微带线中，以测量另一条微带线的FEXT。测试结果表明，亚波长周期微带保护线可以将FEXT降低到传输信号幅度的5%以下，在实际应用中更加灵活。针对高速电路的实际需求，提出了三种隔离结构，并分别验证了它们对微带线间电磁耦合的隔离效果。
This paper proposed a kind of guard traces based on a subwavelength periodic structure to reduce the far-end crosstalk (FEXT) of parallel microstrip lines in the PCB. This technology can be used to improve the false triggering and signal transmitting capacity of a multiconductor transmission line circuit system. In order to explore the present novel guard trace effect on isolating electromagnetic interference (EMI), the frequency response of the mutual capacitance and mutual inductance of the overall circuit system was provided and an equivalent circuit model was built. In comparison to the conventional microstrip line for isolating the EMI between parallel microstrip lines, the novel guard trace can efficiently reduce the mutual capacitance and mutual inductance of the overall circuit system. Thus, it is favorable for suppressing the crosstalk between microstrip lines. The $S$ -parameters calculation result showed that this kind of subwavelength periodic microstrip guard trace can isolate the EMI between two microstrip lines more effectively. Particularly, the conventional grounded guard trace needs a lot of dense grounded holes, which severely influences the wiring design of various layers of a multilayer circuit board. However, the proposed guard trace requires only one grounded hole, which has little influence on the circuit wiring of each layer of a multilayer printed circuit board. In our experiment, the step function signal of 30 ps rise time was imported into one microstrip line to measure the FEXT of the other microstrip line. It was demonstrated by the measurement result that the subwavelength periodic microstrip guard trace can reduce the FEXT to be below 5% of the transmission signal amplitude and is more flexible in practice. In compliance with the actual demand for a high-speed circuit, three isolation structures were proposed, and their isolation effects on the electromagnetic coupling between microstrip lines were verified individually.