A kind of multimode dielectric filter and multimode cascade filter

Abstract

The invention provides a multi-mode dielectric filter, comprising: a multi-mode dielectric resonant cavity, the multi-mode dielectric resonant cavity includes a solid dielectric body and a metal coating covering the outer surface of the dielectric body; a metal transmission line, the metal transmission line The dielectric resonator is separated from the dielectric resonator by a dielectric material; a plurality of coupling structures, the coupling structures are connected between the dielectric resonator and the metal transmission line, and the multimode dielectric resonator is coupled to the metal transmission line through the coupling structure, To form a transmission zero point on either side of the transmission channel, while forming multiple (two or more) resonant frequencies in the passband. The present invention provides a multi-mode dielectric filter and cascaded multi-mode filter, which can realize transmission zero point by direct coupling between a multi-mode dielectric resonant cavity and a metal transmission line, without cross-coupling between multiple cavities; At the same time, each multimode dielectric resonator can realize multiple resonance frequencies, so as to simplify the structure of the dielectric filter.

Description

technical field [0001] The invention relates to the field of filters, in particular to a multimode dielectric filter and a multimode cascaded filter. Background technique [0002] figure 1 It is a structural schematic diagram of an existing multi-mode cascaded filter. Such as figure 1 As shown, the cascaded filter includes two three-mode resonators 310, 350, and one dual-mode resonator 330, wherein the frequency tuning directions of the three-mode resonators are three orthogonal directions, as shown in the figure, the resonant screw 311, 312, 313, and the frequency adjustment direction of the dual-mode resonator 330 is two directions, as shown in the figure, the extension directions of the resonant screws 331, 333. [0003] In this cascaded filter, the coupling between every 2 orthogonal modes in the same tri-mode or dual-mode resonator needs to be made on the right-angle side of the resonator (crossing 45° direction between the 2 modes) Special structural shapes, genera...

AI Technical Summary

Problems solved by technology

The coupling diaphragm of this method is generally welded between two multimode resonant cavities, the process is very complicated, and once the welding is completed, the coupling amount cannot be adjusted, so that the yield rate of the multimode dielectric filter produced in this way Low, poor adjustability, often difficult to achieve the expected insertion loss (s21) and echo (s11) indicators

[0005] Therefore, the disadvantages of traditional multimode filters are: (1) the coupling structure between different modes of the same multimode resonator is complex; (2) the adjacent coupling and cross coupling between different multimode resonators Process realization is difficult, which ultimately affects product performance and pass rate

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