Filter and communication equipment

Abstract

The invention discloses a filter and communication equipment. The filter comprises: a shell provided with a first direction and a second direction perpendicular to the first direction; a first common cavity arranged on the shell; a first filtering branch arranged on the shell, coupled with the first common cavity, consisting of eleven filtering cavities which are coupled in sequence, and forming four first cross coupling zero points; and a second filtering branch adjacent to the first filtering branch along the first direction, coupled with the first common cavity, consisting of nine filtering cavities which are coupled in sequence, and forming three second inductive cross coupling zero points. The first filtering branch is arranged in a broken line shape, the second filtering branch is arranged in a U shape, and the first common cavity is arranged between the first filtering branch and the second filtering branch. Therefore, through arrangement of the common cavity, adjacent arrangement of the filtering branches, broken line arrangement and U-shaped arrangement, the size of the filter can be reduced; and zero point suppression can be realized through cross coupling zero points, and isolation between different filtering branches is improved.

Description

technical field [0001] The present application relates to the technical field of communication, in particular to a filter and a communication device. Background technique [0002] In the mobile communication system, the required signal is modulated to form a modulated signal, which is carried on a high-frequency carrier signal, transmitted to the air through the transmitting antenna, and the signal in the air is received through the receiving antenna. Among the signals received by the receiving antenna, not only Include the desired signal, but also include other frequency harmonics, noise signals. For the signal received by the receiving antenna, it is necessary to use a filter to filter out unnecessary harmonics and noise signals. Therefore, the designed filter must precisely control the bandwidth of the signal. And if there are multiple channels, you should also consider maintaining high isolation between the passbands of each channel. [0003] The inventors of the pres...

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Problems solved by technology

[0003] The inventors of the present application have found in the long-term research and development work that the filters in the prior art usually include two or more groups of filtering branches with different frequencies, but the different filtering branches are not adjacently arranged and there is no The setting of the common cavity has caused the problem that the current filter is too large, especially when more filtering branches are involved; and, when there are multiple filtering branches at the same time, the filtering The out-of-band rejection performance of the filter is poor, and it is difficult to achieve a high degree of isolation between channel signals of different filtering branches

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