Hong Binbin, Feng Naixing, Chen Jing, Wang Guo Ping, Doychinov Viktor, Clarke Roland, Cunningham John, Robertson Ian, Somjit Nutapong
Opt Express. 2020 Sep 14;28(19):27903-27918. doi: 10.1364/OE.399160.
We demonstrate an air-core single-mode hollow hybrid waveguide that uses Bragg reflector structures in place of the vertical metal walls of the standard rectangular waveguide or via holes of the so-called substrate integrated waveguide. The high-order modes in the waveguide are substantially suppressed by a modal-filtering effect, making the waveguide operate in the fundamental mode over more than one octave. Numerical simulations show that the propagation loss of the proposed waveguide can be lower than that of classic hollow metallic rectangular waveguides at terahertz frequencies, benefiting from a significant reduction in Ohmic loss. To facilitate fabrication and characterization, a proof-of-concept 20 to 45 GHz waveguide is demonstrated, which verifies the properties and advantages of the proposed waveguide. A zero group-velocity dispersion point is observed at near the middle of the operating band, which is ideal for reducing signal distortion. This work offers a step towards a hybrid transmission-line medium that can be used in a variety of functional components for multilayer integration and broadband applications.
我们展示了一种空芯单模混合波导，它使用布拉格反射器结构来替代标准矩形波导的垂直金属壁或所谓的基片集成波导的通孔。波导中的高阶模通过模式滤波效应得到显著抑制，使得波导在超过一个倍频程的范围内以基模运行。数值模拟表明，在太赫兹频率下，所提出的波导的传播损耗可以低于经典的空心金属矩形波导，这得益于欧姆损耗的显著降低。为了便于制造和表征，展示了一个20至45 GHz的概念验证波导，它验证了所提出波导的特性和优点。在工作频段的中部附近观察到一个零群速度色散点，这对于减少信号失真非常理想。这项工作朝着一种混合传输线介质迈出了一步，这种介质可用于各种功能组件，以实现多层集成和宽带应用。
