中国物理B ›› 2022, Vol. 31 ›› Issue (7): 78401-078401.doi: 10.1088/1674-1056/ac4f4f
Ming-En Tian(田明恩)1, Zhi-He Long(龙之河)2, Li-Jun Feng(冯丽君)1, Lei-Lei He(贺磊磊)1, and Tian-Liang Zhang(张天良)1,†
Ming-En Tian(田明恩)1, Zhi-He Long(龙之河)2, Li-Jun Feng(冯丽君)1, Lei-Lei He(贺磊磊)1, and Tian-Liang Zhang(张天良)1,†
摘要: A triple-channel bandpass filter with switchable and tunable functions is proposed, which is based on a triple-mode cross resonator. The varactors and switching diodes are loaded at the end of the resonator. Because of the use of switches, resonators have four working states: conventional single-mode, two dual-modes, and one triple-mode. The varactor makes the channel independently adjustable. Finally, a triple-channel bandpass filter with switchable and tunable functions is designed by using two identical triple-mode resonator coupling structures. To solve the problem of whether each channel in the multi-channel filter is independently adjustable, this paper gives a simple and rigorous judgment method, namely rank criterion, which is a necessary and sufficient condition for each channel to be independently adjustable. The method of designing an element variable coupling matrix (EVCM) is adopted, which can not only obtain the desired frequency response through adjustable elements but also help to select resonators and coupling modes in the actual circuit design. The final circuit size of the designed filter is 0.29 λg×0.26 λg. The measured results are in good agreement with the simulation results.
中图分类号: (Filters)