Dielectric waveguide filter

Abstract

The invention discloses a dielectric waveguide filter, comprising: a plurality of first resonant cavities which are connected with each other to form an upper resonant cavity and a plurality of secondresonant cavities which are connected with each other to form a lower resonant cavity; the upper resonant cavity and the lower resonant cavity are overlapped; the upper resonant cavity and the lowerresonant cavity are overlapped; the upper resonant cavity and the lower resonant cavity are overlapped. Each of the first resonant cavities has a first window coupling structure, the first window coupling structure comprising: a first window provided at a weakest point of a higher-order mode magnetic field distribution in the first resonant cavity, and / or a second window provided at a strongest point of a higher-order mode electric field distribution in the first resonant cavity; Each second resonator has a second window coupling structure corresponding to a first window coupling structure, and the first window coupling structure cooperates with the second window coupling structure to eliminate higher order modes of the dielectric waveguide filter. The invention provides a dielectric waveguide filter which increases the far-end harmonic suppression of the dielectric waveguide filter and improves the suppression frequency range by providing window coupling structures which reduce the coupling between higher-order modes.

Description

technical field [0001] The invention relates to the field of filters, in particular to a dielectric waveguide filter. Background technique [0002] With the rapid development of wireless mobile communication technology, the requirements for the far-end out-of-band performance of the dielectric waveguide filter are getting higher and higher, and the suppression degree in the high-order mode frequency band of the existing dielectric waveguide filter is inevitably changed. The problem is that the harmonics are close, usually 1.3 times the frequency. In order to solve this problem, it is usually necessary to use a multi-order low-pass filter to suppress the high-order mode that appears out of the far-end band, and the additional low-pass filter increases the area and insertion loss. [0003] In order to further improve the far-end suppression, it is also possible to use a dielectric waveguide filter and a cascaded metal cavity. The far-end harmonics of the metal cavity are bet...

AI Technical Summary

Problems solved by technology

The far-end harmonics of the metal cavity are better. Cascading the metal cavity and the dielectric waveguide filter can improve the far-end rejection, but the volume occupied by the metal cavity is large, and this cascading method is difficult to achieve the same as the dielectric waveguide filter. volume of

[0004] In addition, the TEM (Transverse Electric and Magnetic Field, electromagnetic field) mode can also be used to improve the far-end suppression. The harmonics of the TEM mode are farther than the dielectric waveguide, but its Q value is lower than that of the dielectric waveguide, and its performance is worse than that of the dielectric waveguide.

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