梯度模型表征粗糙度的柔性传输线损耗分析

Effect of roughness on the loss of the flexible transmission lines

为了解决高频柔性通信系统中导体表面粗糙度制约传输性能的问题,提出了一种柔性分段共面波导传输线结构,采用梯度模型分析了均方根粗糙度Rq对该传输线损耗特性的影响。通过表面阻抗与衰减常数理论解释了导体表面粗糙度使传输损耗增大和带宽偏移的现象。仿真与实测结果表明,该传输线的损耗随粗糙度Rq的增加而变大,当Rq在0~3μm变化时,与光滑导体相比,传输线插入损耗最大增加了1.98 dB,但仍能在21~40 GHz保持稳定的传输带宽。加工实物在不同铜导体表面Rq值下的性能与仿真结果比较吻合。该研究对于小型柔性电子线路的高可靠性设计具有一定意义。

A flexible segmented coplanar waveguide transmission line structure was proposed to solve the problem of conductor surface roughness restricting transmission performance in high frequency flexible communication system.The influence of root mean square roughness Rq on the loss characteristics of the flexible transmission line was analyzed by current accurate gradient model.The increment of the transmission loss increasing and the shift of the bandwidth,which is caused by the surface roughness of the conductor,was explained by the theory of surface impedance and attenuation constant.The simulated and measured results show that the loss of the transmission line becomes larger with the increase of the roughness Rq.When Rq varies from 0μm to 3μm,the insertion loss increases by a maximum of 1.98 dB compared to a smooth conductor,while a stable transmission bandwidth from 21 GHz to 40 GHz is maintained.The performance of the fabricated lines is in good agreement with the simulation results.This work provides solutions for the high reliability design of small electronic circuits.