Small-size medium loading double-frequency filter with small frequency ratio

Abstract

The invention discloses a small-size medium loading dual-frequency filter with a small frequency ratio. The small-size medium loading dual-frequency filter comprises a first dual-mode resonant cavity, a second dual-mode resonant cavity and a coupling window, the whole filter is symmetrical about the central plane of the coupling window. The first dual-mode resonant cavity internally comprises a rectangular metal coupling piece, a first metal three-cake-piece loading resonance rod, a second metal three-cake-piece loading resonance rod, a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, a first supporting medium and a second supporting medium. According to the invention, a novel dual-mode resonant structure and a multilayer dielectric substrate loading technology are adopted, so that the dual-frequency filtering characteristic of a cavity with an extremely small size and a small frequency ratio is realized. Therefore, the invention meets the design requirement of a small dual-frequency communication system with a small frequency ratio, and can be applied to microwave electronic systems such as base stations, radars and remote sensing in mobile communication.

Description

technical field [0001] The invention relates to the field of microwave technology, in particular to a small-sized medium-loaded dual-frequency filter with a small frequency ratio. Background technique [0002] With the rapid development of wireless communications, spectrum resources are becoming increasingly scarce. In order to improve spectrum utilization in a compact structure, multi-frequency filters can alleviate the problem of spectrum resource shortage to a certain extent. At present, the most commonly used multi-frequency filters are dual-frequency filters. However, there are requirements for low insertion loss, high power capacity and high stability in mobile communication base stations, satellite communication systems and military communication systems. Therefore, the medium-loaded filter with the advantages of low insertion loss, high Q value (quality factor), small size, high power capacity and high temperature stability is one of the key equipment in mobile comm...

AI Technical Summary

Problems solved by technology

[0003] The current dielectric-loaded filters are all realized by dielectric resonators, but dielectric resonators have problems such as difficult harmonic suppression, difficult processing and high cost of special-shaped dielectric resonators, and for small-scale dielectric-loaded dual-frequency filters with small frequency ratios. Said that the control of the two passband frequency and bandwidth is more difficult

Therefore, it is a great challenge to design a small dielectric-loaded dual-band filter with good stop-band characteristics and small frequency ratio.

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