This paper presents a mechanical reliability study of 3-dB waveguide hybrid couplers in submillimeter and terahertz bands. To show the necessity of improving the mechanical properties of the coupler’s branch in submillimeter and terahertz bands, a comprehensive study regarding the displacement of hybrid branch variation with varying width-length ratio and height-length ratio has been completed. In addition, a modified 3-dB waveguide hybrid coupler is designed and presented. Compared with the traditional branch structure, the proposed hybrid consists of a modified middle branch with circular cutouts at the top and bottom on both sides instead of the traditional rectangle branch, which increases the branch size and improves its mechanical reliability while achieving the same performance. Simulation results show that the deformation of the modified hybrid branch is 22% less than those of other traditional structure designs under the same stress. In practice, a vibration experiment is set up to verify the mechanical reliability of hybrid couplers. Measurement results show that the experiment deteriorates the coupling performance. Experimental results verify that the performance of the novel structure coupler is better than that of a traditional structure branch hybrid coupler under the same electrical properties.

本文介绍了亚毫米和太赫兹波段 3-dB 波导混合耦合器的机械可靠性研究。为了表明在亚毫米和太赫兹波段提高耦合器分支机械性能的必要性，已经完成了关于不同宽长比和高长比的混合分支变化位移的综合研究。此外，还设计并展示了一种改进的 3-dB 波导混合耦合器。与传统的分支结构相比，所提出的混合结构由一个改进的中间分支组成，中间分支的顶部和底部两侧都有圆形切口，而不是传统的矩形分支，在实现相同性能的同时，增加了分支尺寸并提高了其机械可靠性。仿真结果表明，在相同应力下，改进后的混合分支的变形比其他传统结构设计的变形小22%。在实践中，建立了振动实验来验证混合耦合器的机械可靠性。测量结果表明，该实验恶化了耦合性能。实验结果验证了在相同电性能下，新型结构耦合器的性能优于传统结构分支混合耦合器。