Dual Post Resonator With Tuning Screw Gap

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Solution Overview

Problem

Conventional radio-frequency filters, particularly combline resonators, face challenges in achieving high power handling, low insertion loss, and tunability due to manufacturing limitations and the nonlinear variation of resonant frequency with tuning screw intrusion, leading to limited frequency tunability and increased complexity.

Innovation Solution

The use of two resonator posts with a longitudinal channel for the tuning screw, allowing adjustable magnetic field coupling and reduced size, enabling high power handling and wide frequency tunability without increasing insertion loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional single combline resonator with a tuning screw is used, then manufacturing tolerances can be compensated, but the frequency tunability range is limited to only a few per cent and the power handling capability is reduced

Engineering Contradiction:
Improvefrequency tunabilityVSAvoidpower handling capability
Core Design Contradiction:
Adaptability or versatilityVSPower

Solution Approach 1:

The resonator is divided into two separate resonator posts instead of using a single resonator structure. This segmentation allows the tuning screw to be positioned between the two posts where the electric field is weaker, enabling greater frequency tunability without compromising power handling capability. The two posts can be independently optimized for their respective functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tuning screw is repositioned from the traditional location at the top of the resonator to a position between two resonator posts. This spatial reconfiguration in a different dimension allows the tuning mechanism to operate in a region with lower electric field intensity, thereby achieving wider frequency tuning range while maintaining high power handling capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a tuning screw is used to retune the resonator to a different frequency, then frequency adjustment is possible, but the intrusion depth must be limited to maintain power handling and the tunability range is restricted

Engineering Contradiction:
Improvefrequency adjustment rangeVSAvoidtuning screw intrusion depth
Core Design Contradiction:
Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The tuning screw is relocated to a different spatial dimension - between the two resonator posts rather than at the top. This positional change allows the screw to achieve significant frequency tuning effect without requiring deep intrusion that would compromise the gap size and power handling capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The tuning screw operates in a localized region between the two posts where the electric field intensity is lower. This local quality difference allows the tuning mechanism to function effectively with minimal intrusion depth, as the weaker electric field in this region reduces the risk of arcing and maintains power handling capability.

Inventive Principle:
Principle #3Local quality

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 configuration results in a resonator structure with reduced dimensions, increased tunability, and improved power handling, allowing for frequency tuning over a 30% range without degrading RF characteristics, making it suitable for mobile communication base stations.

Implementation Method 1

the two resonator posts being separated by a gap and in proximity with each other for magnetic field coupling of the two posts

Methodology Applied
Scientific EffectMagnetic field coupling: Magnetic Field

Data Source

PatentEP3012901B1A resonator, a radio frequency filter, and a method of filtering
Publication Date: 2020.07.15 ALCATEL LUCENT SA
  • EP3012901B1 patent drawingFigure 1~3
  • EP3012901B1 patent drawingFigure 4
  • EP3012901B1 patent drawingFigure 5~7

AI summary

A resonator is provided comprising a resonant chamber, each chamber comprising a first wall, a second wall opposite the first wall, and side walls; in which the resonant chamber houses two resonator posts, the two resonator posts being separated by a gap and in proximity with each other for magnetic field coupling of the two posts; one of the two posts being grounded on the first wall so as to extend into the chamber from the first wall; the other of the two posts being grounded on the second wall so as to extend into the chamber from the second wall.