Waveguide Bandpass Filter Tuning With Mobile Perturbators
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Solution Overview
Problem
Existing band-pass filters with metal cylinders face challenges in achieving stable frequency response performances, high insertion losses, and inefficient tuning mechanisms, particularly for frequencies below 15GHz, which limits their operational efficiency and adaptability.
Innovation Solution
The introduction of mobile perturbator elements associated with each protruding element within the resonant cavities allows for finer tuning of the frequency response without requiring electric circuits or control lines, reducing production costs and enhancing mechanical reliability and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If adjustment screws are screwed into protruding elements to tune the pass band, then frequency tuning is achieved, but insertion losses increase excessively
Solution Approach 1:
The harmful screw structure is extracted and removed from the system. Instead of using screws that cause high insertion losses, the patent uses movable perturbator elements that can be positioned within the resonant cavity to achieve frequency tuning without the detrimental effects of threaded connections.
Solution Approach 2:
Movable perturbator elements are introduced as intermediary components between the fixed protruding elements and the tuning mechanism. These perturbators can be selectively positioned to modify the resonant frequency by perturbing the electromagnetic field, achieving tuning without direct mechanical contact that causes losses.
2Adaptability or versatility
If adjustment screws are used to move closer to or away from protruding elements, then pass band adjustment is achieved, but the mechanism becomes complex and expensive
Solution Approach 1:
The complex screw-threaded adjustment mechanism is extracted and replaced. The patent eliminates the need for threaded holes, screw threads, and associated precision machining, thereby simplifying the structure and reducing manufacturing complexity and cost.
Solution Approach 2:
The tuning mechanism changes from mechanical screw displacement to positional movement of perturbator elements. By changing the parameter being adjusted from screw penetration depth to perturbator position, the system achieves the same functional result with a simpler mechanism that is easier to manufacture and control.
3Productivity
If iris diaphragms extend through the entire height of resonant cavities, then connection between cavities is achieved, but frequency response stability deteriorates
Solution Approach 1:
The iris diaphragm structure is modified to have different properties in different regions. Instead of extending through the entire height, the diaphragm is positioned at a specific height within the resonant cavity where it optimally couples signals while minimizing negative effects on frequency response stability. This localized positioning creates different functional zones within the cavity.
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 solution enables more stable and efficient frequency tuning with reduced insertion losses, increased operating power, and reduced bulk, while maintaining a consistent filter response, thus improving the performance and cost-effectiveness of band-pass filters.
Implementation Method 1
a mechanism for tuning the resonance frequency of the resonant cavities which make up the filter
Data Source
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AI summary
Tunable band-pass filter that allows to re-configure its response in frequency thanks to a tuning mechanism of the frequency of resonance of the resonant cavities. The mechanism is inserted inside each resonator of the guide filter in order to tune the band-pass filter.