宽带双周期性BST电容加载共面波导移相器

提出了一种双周期性BST电容加载共面波导传输线的移相器结构。基于这种结构设计制作的铁电薄膜移相器较好地解决了整个电路的阻抗匹配问题,其反射损耗的波纹在较宽的工作频带内趋于同一幅度。在沉积有钛酸锶钡(BST)薄膜的氧化镁基片上设计并制作了一个宽带双周期性BST叉指电容加载共面波导移相器,测试结果显示该移相器的反射损耗在0~15GHz内保持在–15dB,其中在14.5GHz处,在30V的外加偏压下其移相能力可达35o。

CPW wide band phase shifter double periodically loaded with BST capacitors

A coplanar waveguide (CPW) phase shifter was proposed, which was double periodically loaded with BST capacitors. The impedance matching problem was well solved in the phase shifter designed using this unique structure. In the whole operation frequency range, the local return loss maxima of the phase shifter appear at more or less the same level. A CPW wide band phase shifter loaded with interdigitated BST capacitors was designed and fabricated on MgO substrate coated with BST thin film. Measured results show that its return loss is –15 dB at 0~15 GHz, and 14.5 GHz, its differential phase shift is 35o under 30 V applied bias voltage.