A quadruple-mode dual-wideband filter is proposed in this paper. The proposed cavity resonator consists of two symmetrical conductive posts and a pair of downward pointing L-shaped coupling probes in a cylindrical metal cavity, while four resonant modes of the resonator are classified as TM₁₁ mode, TM₀₁ mode and a pair of degenerate TE modes (TE+ mode and TE− mode). Successful excitation of the four modes is attributed to the two L-shaped coupling probes. The first wide-passband is realized by TM₁₁ mode and TM₀₁ mode, while the second wide-passband is achieved by TE+ mode and TE− mode. Finally, a quadruple-mode dual-wideband filter is designed, fabricated and measured. The measurements are in good agreement with the simulations, which validates the design.

中文翻译：

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基于四模金属腔的微型双宽带滤波器

本文提出了一种四模双宽带滤波器。所提出的腔谐振器由两个对称的导电柱和一对位于圆柱形金属腔中的向下指向的 L 形耦合探针组成，而谐振器的四种谐振模式分为 TM ₁₁模式、TM ₀₁模式和一对退化的 TE模式（TE+ 模式和 TE- 模式）。四种模式的成功激发归因于两个 L 形耦合探头。通过TM ₁₁模式和TM ₀₁实现第一个宽通带模式，而第二个宽通带是通过TE+模式和TE-模式实现的。最后，设计、制造和测量了四模双宽带滤波器。测量结果与模拟非常吻合，从而验证了设计。