This letter reports on a new type of miniaturized RF co-designed bandpass filter/circulator (BPFC). Miniaturization is achieved by: 1) capacitively loading a multi-mode ferrite-based disk resonator; 2) combining the function of an RF circulator and a bandpass filter (BPF) within the volume of a single microwave component; and 3) by tuning its transfer function. The proposed BPFC exhibits a quasi-elliptic power transmission response in the forward direction—passband in-between four transmission zeros (TZs)—and an all-stop response in the reverse one. Reconfigurability is achieved by tuning the capacitive loads of the ferrite disk and the mixed electromagnetic coupling elements in the RF input/output. For proof-of-concept validation purposes, an S-band tunable prototype was designed, built, and measured. It demonstrated multiple levels of tuning. These include the frequency tuning of 1.27:1, the bandwidth tuning of 1.73:1, the out-of-band isolation tuning, and intrinsic switching-off.

中文翻译：

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具有可调中心频率、带宽和带外隔离的射频协同设计带通滤波器/环行器

这封信报告了一种新型小型化射频协同设计的带通滤波器/循环器 (BPFC)。小型化是通过以下方式实现的：1）电容加载多模铁氧体圆盘谐振器；2）在单个微波元件的体积内结合了射频环行器和带通滤波器（BPF）的功能；3) 通过调整其传递函数。所提出的 BPFC 在正向表现出准椭圆功率传输响应——通带在四个传输零点 (TZ) 之间——而在反向表现出全停止响应。可重构性是通过调谐铁氧体盘的容性负载和 RF 输入/输出中的混合电磁耦合元件来实现的。出于概念验证验证的目的，设计、构建和测量了 S 波段可调原型。它展示了多个级别的调整。