High Frequency Filter Inner Conductor Coupling Element

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Solution Overview

Problem

Existing high-pass filters in coaxial structures require multiple inner conductor portions to achieve the necessary blocking characteristics, leading to high tolerance sensitivity and compact design challenges, especially in mobile technology where small distances between line sections are critical.

Innovation Solution

Incorporating an additional inner conductor coupling element, which can be metallic or dielectrically conductive, to enhance capacitive coupling between inner conductor portions, allowing for the generation of additional locking poles and reducing sensitivity, enabling a more compact and stable filter design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple inner conductor portions are used to achieve necessary blocking characteristics, then the filter performance is improved, but the tolerance sensitivity increases and the design becomes more complex

Engineering Contradiction:
Improvefilter performanceVSAvoidtolerance sensitivity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent introduces an intermediate structure (the coupling element with cavity) between the inner conductor portions to mediate the capacitive coupling. This intermediary structure provides a controlled environment for the electric field interaction, reducing sensitivity to dimensional variations of the inner conductor portions themselves while maintaining the necessary coupling characteristics for filter performance

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the distance between inner conductor portions is reduced to maintain compact size, then the capacitive coupling increases, but the tolerance sensitivity increases

Engineering Contradiction:
Improvefilter sizeVSAvoidtolerance sensitivity
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The coupling element acts as an intermediary that allows compact spacing between inner conductor portions while providing a controlled cavity structure. This mediator stabilizes the electric field distribution in the reduced space, enabling strong capacitive coupling without proportionally increasing tolerance sensitivity to manufacturing variations

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If additional inner conductor portions are added to improve blocking characteristics, then the filter performance improves, but the device complexity increases

Engineering Contradiction:
Improveblocking characteristicsVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coupling element with its cavity structure serves multiple functions simultaneously: it provides the necessary capacitive coupling between inner conductor portions, creates the locking pole through its geometric configuration, and maintains mechanical support. This multi-functionality reduces the need for additional separate components, thereby improving blocking characteristics without proportionally increasing device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The solution results in improved electrical properties, reduced tolerance sensitivity, and a more compact design with lower production costs, while maintaining mechanical stability and good intermodulation behavior, suitable for use in mobile radio technology.

Implementation Method 1

The inner conductor portions have (if the entire arrangement should have a compact size) usually very low dimensioned interruptions, whereby the corresponding inner conductor portions are coupled to their end faces capacitively.

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

The front-side capacitive coupling between the inner conductors also increases with increasing cross-sectional area of ​​the lines and with increasing dielectric constant of the material, which can be in the gap between the lines.

Methodology Applied
Scientific EffectDielectric: Dielectric

Data Source

PatentEP2449622B1High frequency filter
Publication Date: 2021.04.07 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2449622B1 patent drawingFigure 1a~1b
  • EP2449622B1 patent drawingFigure 1c~1e
  • EP2449622B1 patent drawingFigure 2a~2k

AI summary

The invention relates to an improved high frequency filter (high pass filter) that is characterized by the following features: in addition to the at least both capacitively coupled inner conductor front faces (5b) or the capacitively coupled inner conductor end segments (5c) of two coupled inner conductor segments (5a), at least one further inner conductor coupling device (15) or at least one further inner conductor coupling element (115) is provided, the at least one further inner conductor coupling device (15) or the at least one further inner conductor coupling element (115) is arranged in an at least partially overlapping manner with the inner conductor end segments (5c) of the coupled inner conductor segments (5b), and the branch line (7) runs between the inner conductor coupling device (15) or the inner conductor coupling element (115) and the outer conductor (1).