A dielectric dual-mode bandpass filter based on tm mode and its control method

Abstract

The invention belongs to the technical field of microwave communication, and discloses a dielectric dual-mode band-pass filter based on TM mode and a control method thereof. The filter comprises a dielectric resonator, and the outer surface of the dielectric resonator is coated with silver. Controlling a resonant frequency of a resonant mode of the dielectric resonator through a radius of the dielectric resonator; Opening a through hole at the intersection of the magnetic field distributions of the two resonant modes of the dielectric resonator, and controlling the coupling strength between the two resonant modes of the dielectric resonator through the through hole; A coaxial probe is introduced as a port coupling structure in a direction parallel to the electric field of the resonant modeof the dielectric resonator, and the external quality factor is controlled by the position of the coaxial probe and the length of the inner conductor of the coaxial probe. The dielectric dual-mode band-pass filter of the invention has the advantages of simple structure, small volume and convenient realization, adopts the method of silver plating on the surface of a dielectric resonator, does notneed a metal external cavity, and is different from the traditional dielectric filter.

Description

technical field [0001] The invention belongs to the technical field of microwave communication, and in particular relates to a dielectric double-mode bandpass filter based on TM mode and a control method. Background technique [0002] Microwave filter is an important device in the radio frequency front end of the wireless communication system, and has a direct impact on the performance of the entire wireless communication system. The microwave filter can select the frequency required in the communication process so that it can pass through smoothly, and at the same time suppress the unnecessary frequency to avoid its impact on communication, so as to ensure good communication signal transmission and improve communication quality. [0003] With the rapid development of wireless communication systems, spectrum resources have become increasingly scarce, and the frequency gap between wireless signals has also become smaller and smaller, which puts forward higher requirements on ...

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Problems solved by technology

[0010] (1) In the published dielectric double-mode filter articles or patent documents, a metal cavity is usually used outside the dielectric resonator to realize electromagnetic wave shielding. The metal cavity not only increases the volume of the filter, but also increases the structural processing. technical difficulty and processing cost

[0011] (2) In the published dielectric double-mode filter articles or patent documents, the resonant frequency of the two resonant modes of the dielectric resonator and the coupling strength between the two resonant modes are usually used to cut the angle of the dielectric block, or by inserting screws To control, the structure is more complicated, the volume is larger, the processing technology is difficult and the cost is high

[0012] (3) The published dielectric dual-mode filter articles or patent documents mostly involve single-cavity dielectric dual-mode filters, which are not suitable for multi-stage multi-cavity high-performance filter design, and the filtering performance of the proposed method and structure is limited.

[0014] Difficulty: How the existing technology can effectively reduce the size of the filter while maintaining high filtering performance is relatively difficult

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