Schaich Tobias, Molnar Daniel, Al Rawi Anas, Payne Mike
Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK.
BT Labs, Adastral Park, Orion building, Martlesham Heath, Ipswich, IP5 3RE, UK.
Sci Rep. 2020 Nov 27;10(1):20754. doi: 10.1038/s41598-020-77703-w.
Planar Goubau lines show promise as high frequency, low-loss waveguides on a substrate. However, to date only numerical simulations and experimental measurements have been performed. This paper analytically investigates the surface wave mode propagating along a planar Goubau line consisting of a perfectly conducting circular wire on top of a dielectric substrate of finite thickness but infinite width. An approximate equation for the propagation constant is derived and solved through numerical integration. The dependence of the propagation constant on various system parameters is calculated and the results agree well with full numerical simulations. In addition, the spatial distribution of the longitudinal electric field is reported and excellent agreement with a numerical simulation and previous studies is found. Moreover, validation against experimental phase velocity measurements is also reported. Finally, insights gained from the model are considered for a Goubau line with a rectangular conductor. The analytic model reveals that the propagating mode of a planar Goubau line is hybrid in contrast to the transverse magnetic mode of a classic Goubau line.
平面古鲍线有望成为衬底上的高频、低损耗波导。然而，迄今为止仅进行了数值模拟和实验测量。本文对沿平面古鲍线传播的表面波模式进行了分析研究，该平面古鲍线由位于有限厚度但无限宽度的电介质衬底顶部的理想导电圆形导线组成。推导了传播常数的近似方程，并通过数值积分求解。计算了传播常数对各种系统参数的依赖性，结果与全数值模拟吻合良好。此外，报告了纵向电场的空间分布，并发现与数值模拟和先前研究结果高度一致。此外，还报告了与实验相速度测量结果的对比验证。最后，针对具有矩形导体的古鲍线，考虑了从该模型中获得的见解。分析模型表明，平面古鲍线的传播模式是混合模式，这与经典古鲍线的横向磁模式不同。
