In this paper, a high selectivity wideband 180° phase shifter (PS) with the functionality of vertical transition is presented. The whole circuit is realized based on the hybrid microstrip/slotline (SL) structure. By introducing the short-circuited microstrip stepped-impedance resonators, two transmission zeros are created to improve the selectivity of the PS. With the SL in the center ground layer, a frequency independent 180° PS can be obtained. The even/odd-mode equivalent circuits of the proposed PS are analyzed to guide the design. Finally, a practical wideband 180° PS with high filtering selectivity is designed and fabricated to verify the design theory.

中文翻译：

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具有垂直转换功能的高选择性宽带 180° 移相器

在本文中，提出了一种具有垂直过渡功能的高选择性宽带180°移相器（PS）。整个电路是基于混合微带/槽线(SL)结构实现的。通过引入短路微带阶梯阻抗谐振器，创建了两个传输零点，以提高 PS 的选择性。使用中心接地层中的 SL，可以获得与频率无关的 180° PS。分析了所提出的 PS 的偶/奇模等效电路以指导设计。最后，设计并制作了具有高滤波选择性的实用宽带180°PS，以验证设计理论。