Resonant Cavity Filter Tuning Element with Non-Threaded Pin
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Solution Overview
Problem
Conventional resonant cavity filters in cellular communications systems face issues with metal debris formation due to threading between tuning elements, leading to passive intermodulation (PIM) distortion, which degrades electrical performance and data transfer efficiency.
Innovation Solution
The use of elongated pin members with non-threaded contact portions and turret members with flexible fingers or elastic rings to secure the pin members in place, eliminating metal-to-metal contacts within the filter cavity and reducing PIM distortion by preventing metal shavings from entering the resonator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If threading is used to secure tuning elements in resonant cavity filters, then the tuning elements can be firmly fixed in position, but metal debris is generated leading to PIM distortion
Solution Approach 1:
The patent removes the threading feature from the tuning element that causes metal debris generation. Instead of using threaded connections, the invention employs a smooth pin member that is inserted into and retained by a recess in the resonator, eliminating the metal-to-metal contact that produces debris while maintaining secure positioning.
Solution Approach 2:
The patent introduces an intermediary retention mechanism where a recess in the resonator body holds the smooth pin member. This intermediary structure provides secure fixation without requiring threading, thereby preventing metal debris generation while maintaining the tuning element's fixed position.
2Ease of operation
If conventional tuning screws with threading are used, then adjustment is possible, but passive intermodulation distortion increases due to metal shavings
Solution Approach 1:
The patent extracts the harmful threading feature from the tuning mechanism while preserving the essential function of position adjustment. The smooth pin member can be inserted to different depths in the resonator to achieve tuning, and its position is secured by the recess without generating metal shavings that cause PIM distortion.
3Stability of the object's composition
If threaded connections are used for mounting tuning elements, then secure fixation is achieved, but metal-to-metal contact causes debris formation
Solution Approach 1:
The patent completely removes the threading feature from the tuning element design. The smooth pin member achieves stable fixation through geometric interlocking with the recess in the resonator body, eliminating metal-to-metal contact and the generation of metal shavings that would otherwise occur with threaded connections.
Data Source
AI summary
A resonant cavity filter includes a housing having a resonator therein, and a tuning element including an elongated pin member having a conductive outer surface. The tuning element is mounted for insertion of the elongated pin member into an interior of the resonator. The conductive outer surface includes a contact portion by which the elongated pin member is secured in a desired position to adjust a frequency response of the resonant cavity filter, where the contact portion is free of threading.