This paper presents a miniaturized RF MEMS tunable bandpass filter design developed by application of folded ridged quarter-mode substrate integrated waveguide cavity. Using packaged RF MEMS SP4T chips, a switchable reactive loading is applied to the folded ridged quarter-mode substrate integrated waveguide cavity, tuning the resonance frequency. Overall miniaturizations of 70.3% and 78.8% are achieved for inductively- and capacitively-loaded filters compared to an RF MEMS tunable filter using half-mode substrate integrated waveguide. Here, an analysis of inductive or capacitive loading along with their advantages and disadvantages are discussed. Two different two-pole folded ridged quarter-mode substrate integrated RF MEMS tunable bandpass filters are designed and measured. The first prototype employing inductive loading achieves 4.4% tuning range at a center frequency of 1.713 GHz, insertion loss of 3.10–3.92 dB, and return loss greater than 15 dB for all tuning modes. The second prototype employing capacitive loading is measured with a 35.2% tuning range at a center frequency of 865 MHz, insertion loss of 1.6–4.3 dB, and return loss greater than 10 dB for all tuning modes. The reported performance and extreme miniaturization of folded ridged quarter-mode substrate integrated waveguide cavities shows great promise for their application in tunable filter design.

中文翻译：

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小型化折叠脊四分之一模式基板集成波导 RF MEMS 可调谐带通滤波器

本文介绍了一种应用折叠脊四分之一模衬底集成波导腔开发的小型化RF MEMS可调带通滤波器设计。使用封装的 RF MEMS SP4T 芯片，将可切换的无功负载施加到折叠脊状四分之一模衬底集成波导腔，调整谐振频率。与使用半模基板集成波导的 RF MEMS 可调滤波器相比，电感和电容负载滤波器实现了 70.3% 和 78.8% 的整体小型化。在这里，讨论了感性或容性负载的分析及其优缺点。设计并测量了两种不同的双极折叠脊四分之一模式衬底集成射频 MEMS 可调带通滤波器。采用感应负载的第一个原型实现了 4。中心频率为 1.713 GHz 时的调谐范围为 4%，插入损耗为 3.10–3.92 dB，所有调谐模式的回波损耗均大于 15 dB。采用容性负载的第二个原型在 865 MHz 中心频率、1.6–4.3 dB 插入损耗和大于 10 dB 回波损耗的所有调谐模式下以 35.2% 的调谐范围进行测量。所报道的折叠脊四分之一模衬底集成波导腔的性能和极端小型化显示了它们在可调谐滤波器设计中的应用前景。所有调谐模式的回波损耗均大于 10 dB。所报道的折叠脊四分之一模衬底集成波导腔的性能和极端小型化显示了它们在可调谐滤波器设计中的应用前景。所有调谐模式的回波损耗均大于 10 dB。所报道的折叠脊四分之一模衬底集成波导腔的性能和极端小型化显示了它们在可调谐滤波器设计中的应用前景。