Dielectric filter

Abstract

The invention provides a dielectric filter. The dielectric filter comprises at least one first resonator working in a TE102 mode and at least one second resonator working in a TE101 mode, wherein the top surface and the bottom surface of the first resonator respectively comprise a top surface center and a bottom surface center which are symmetrical; a pair of first tuning blind holes are symmetrically formed in the top surface of the first resonator about the center of the top surface; a bottom blind hole is formed in the center of the bottom surface of the first resonator; and / or the first resonator has a through hole penetrating through the top surface and the bottom surface, and the through hole is located on a perpendicular bisector corresponding to a connecting line of the pair of first tuning blind holes. Therefore, the frequency of loading the TE101 mode can be reduced or increased under the condition that the influence on the frequency of loading the TE102 mode is small, the low-frequency suppression performance can be greatly improved, the structure is simple, implementation is easy, and the design flexibility and adaptability of the dielectric filter are further improved.

Description

technical field [0001] The invention relates to the technical field of filters, in particular to a dielectric filter. Background technique [0002] Filter is an indispensable frequency selective device in wireless communication. Dielectric filters based on ceramics have more and more application prospects due to their compact size and excellent performance. [0003] Chinese invention patent CN201980001851.9 discloses a ceramic dielectric filter. The capacitive coupling method of the ceramic dielectric filter is realized by using a double blind hole structure to load the TE102 mode. The structure of capacitive coupling is simple and easy to implement in this way, but because the resonator working in TE102 mode still has TE101 mode and the resonant frequency of TE101 mode is lower than that of TE102 mode, the passband of the ceramic dielectric filter will be low in frequency. Generate spurious harmonics, thereby affecting the suppression performance of the filter at low frequ...

AI Technical Summary

Problems solved by technology

The structure of capacitive coupling is simple and easy to implement in this way, but because the resonator working in TE102 mode still has TE101 mode and the resonant frequency of TE101 mode is lower than that of TE102 mode, the passband of the ceramic dielectric filter will be low in frequency. Generate spurious harmonics, which affect the rejection performance of the filter at low frequencies

Especially when the ceramic dielectric filter has at least two resonators working in the TE102 mode, the respective TE101 modes of these resonators will generate at least two spurious harmonics at the low frequency of the passband, and the harmonics are superimposed on each other when their frequencies are close. Severely affects low-frequency rejection performance

Although the resonant frequency interval of the two modes can be adjusted to a certain extent by adjusting the spacing of the double blind holes of the resonator, the change of the spacing not only affects the frequencies of the two modes at the same time, but also changes the adjacent coupling amount, so the design is limited Larger, the amount of adjustment to the harmonic frequency is also very limited

[0004] In summary, there are obviously inconveniences and defects in the actual use of the existing technology, so it is necessary to improve

Images