Cavity Filter Tuning Structure Without Cover-Mounted Screws
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Solution Overview
Problem
The assembly and tuning processes of existing cavity filters are complex and time-consuming, with uncontrollable fastening of the cover affecting filter frequency selectivity and resonance characteristics.
Innovation Solution
A filtering device with a housing that omits the need for complex cover mounting, featuring a resonant conductor plugged into the inner cavity and a pressing element connected to the housing for adjusting the resonant frequency by pressing or drawing, simplifying assembly and tuning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a cover and tuning screw structure is used in the cavity filter, then the filter can be assembled and tuned, but the assembly and tuning processes become complex and time-consuming
Solution Approach 1:
The patent removes the cover and tuning screw components from the traditional cavity filter structure. Instead of using a separate cover with mounted tuning screws, the invention integrates the tuning function directly into the cavity wall through adjustable capacitive elements or movable shorting pins, eliminating the need for complex cover assembly and simplifying the overall structure.
Solution Approach 2:
The patent combines the functions of the cover, tuning mechanism, and cavity wall into a unified structure. The adjustable capacitive elements or movable shorting pins are directly integrated into the cavity wall, merging the separation between structural components and tuning components, thereby reducing the number of parts and simplifying assembly.
2Reliability
If a cover is fastened to the cavity using screws, then the structure is secured, but the fastening degree becomes uncontrollable and directly affects filter frequency selectivity
Solution Approach 1:
The patent eliminates the screw fastening mechanism entirely by removing the separate cover component. The cavity wall is designed to be self-contained with integrated tuning elements, so no external fastening is required. This removes the source of uncontrollable fastening degree and its adverse effect on frequency selectivity.
Solution Approach 2:
The patent merges the cover function into the cavity wall structure itself, creating a unified enclosure. The tuning elements are directly integrated into the wall, eliminating the interface between cover and cavity where uncontrollable fastening occurs. This integration ensures that structural integrity and frequency selectivity are not compromised by fastening variations.
3Adaptability or versatility
If a tuning screw is mounted on the cover, then the resonance characteristic can be adjusted, but the tuning process becomes time-consuming
Solution Approach 1:
The patent removes the tuning screw mounted on the cover and replaces it with adjustable capacitive elements or movable shorting pins that are directly integrated into the cavity wall. This allows for more direct and faster adjustment of resonance characteristics without the mechanical complexity of screw mounting and rotation.
Solution Approach 2:
The patent employs dynamically adjustable elements such as movable shorting pins or variable capacitive structures that can be quickly repositioned or adjusted along the cavity wall. These elements allow for rapid resonance tuning by simply changing the position or capacitance value, rather than requiring time-consuming screw adjustments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly simplifies the assembly and tuning processes, reducing the impact of cover assembly on performance and shortening tuning time while improving filtering performance.
Implementation Method 1
a resonant conductor 220, disposed inside the inner cavity
Implementation Method 2
a pressing element 230, having one end disposed on the housing and another end suspended, where the pressing element 230 facing a position of an open-circuit end of the resonant conductor, and a distance between the pressing element 230 and the resonant conductor 220 is changed by pressing or drawing the pressing element 230, to adjust a resonant frequency
Data Source
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AI summary
Embodiments of this application provide a filtering device, to effectively simplify assembly and tuning processes. The filtering device includes: a housing, including an inner cavity; a resonant conductor, having a resonance function, and disposed inside the inner cavity; and a pressing element, having one end disposed on the housing and another end suspended, and facing a position of an open-circuit end of the resonant conductor, where a distance between the pressing element and the resonant conductor is changed by pressing or drawing, to adjust a resonant frequency. The filtering device provided in the embodiments of this application is applicable to a plurality of communications devices that need to select a signal frequency.