An optimum approach for designing a TE ₀₁ mode oversized waveguide bend is proposed based on angular-deformed circular waveguide. Due to the deformation of the circular waveguide cross section, the degeneracy of the TE ₀₁ mode and the TM ₁₁ mode is removed, and the mode conversion inside the waveguide bend is weakened. Characterizations of the angular-deformed circular waveguide with different deformation and its influence on the mode spectrum, the transmission loss, and the power capacity are investigated. Based on the analysis results and the coupling-wave theory, a Ka -band broadband oversized deformed circular waveguide bend with the propagating TE ₀₁ mode is designed, fabricated, and measured. A good agreement between the calculation results and the S-parameter measurement of a prototype is achieved. The transmission efficiency is over 95% in the frequency range of 26.5–35.9 GHz (the relative band is over 30%). The near-field test results further demonstrate the high output purity of the TE ₀₁ mode in the working frequency band.

中文翻译：

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用于渐变 TE ₀₁模式弯曲的具有变形横截面的超大圆形波导的研究

提出了一种基于角变形圆形波导设计 TE ₀₁模式超大波导弯曲的最佳方法 。由于圆形波导截面的变形，TE ₀₁模式和TM ₁₁模式的简 并被消除，波导弯曲内部的模式转换减弱。研究了具有不同变形的角变形圆形波导的特征及其对模式谱、传输损耗和功率容量的影响。根据分析结果和耦合波理论，K a设计、制造和测量了 具有传播 TE ₀₁模式的宽带宽带超大变形圆形波导弯曲 。计算结果与原型的 S 参数测量结果非常吻合。在26.5-35.9 GHz频率范围内传输效率超过95%（相对频段超过30%）。近场测试结果进一步证明了TE ₀₁模式在工作频段的高输出纯度 。