HF Filter Coupling Window Segmentation for Parasitic Inductance

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Solution Overview

Problem

Existing HF filter arrangements face challenges in achieving strong capacitive coupling between pot-circuit resonators while minimizing losses and accommodating various broadcast standards, particularly due to parasitic inductive coupling and limited power handling.

Innovation Solution

The introduction of a coupling mechanism with a conductive rod element and rotatable finger elements that divide the coupling window into smaller areas, allowing for adjustable capacitive coupling and reducing parasitic inductive coupling, enabling a stronger capacitive coupling and higher power handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a large coupling window is used to achieve strong capacitive coupling between pot-circuit resonators, then capacitive coupling strength is improved, but parasitic inductive coupling increases

Engineering Contradiction:
Improvecapacitive coupling strengthVSAvoidparasitic inductive coupling
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The coupling window is divided into multiple smaller sub-windows by introducing conductive partitions (such as rod elements or finger elements) within the window. This segmentation reduces the effective area for parasitic inductive coupling while maintaining the capacitive coupling function through multiple distributed coupling points, thereby resolving the contradiction between strong capacitive coupling and reduced parasitic inductive coupling.

Inventive Principle:
Principle #1Segmentation

2Power

If the coupling window area is increased to accommodate higher power, then power handling capability is improved, but parasitic inductive coupling increases

Engineering Contradiction:
Improvepower handling capabilityVSAvoidparasitic inductive coupling
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The coupling window is segmented into multiple smaller sub-windows using conductive partitions, allowing the total window area to be increased for higher power handling while each sub-window maintains a size that minimizes parasitic inductive coupling. The distributed structure provides both power handling capability and reduced parasitic effects.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the coupling window are assigned different functions: the overall window area is sized for power handling, while local sub-regions (sub-windows) are optimized for minimal parasitic inductive coupling. The conductive partitions create local structures that manage electromagnetic field distribution to reduce parasitic effects while maintaining global power handling capability.

Inventive Principle:
Principle #3Local quality

3Device complexity

If a simple coupling structure is used, then device complexity is reduced, but coupling factor adjustment range is limited

Engineering Contradiction:
Improvecoupling structure complexityVSAvoidcoupling factor adjustment range
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The coupling structure incorporates movable or adjustable elements (such as rotatable finger elements or adjustable conductive partitions) that allow the coupling factor to be dynamically adjusted over a wide range. This dynamic capability enables adaptation to different broadcast standards and operating conditions while maintaining a relatively simple overall structure that does not significantly increase device complexity.

Inventive Principle:
Principle #15Dynamics

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 allows for a wide range of coupling factor variation, enhancing filter characteristics for different broadcast standards and increasing dielectric strength, enabling higher power handling and compact design.

Implementation Method 1

a coupling agent with a variably adjustable capacitance is introduced

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

HF filter arrangement with at least two capacitively coupled pot circuit resonators, which are coupled via a common, electrically conductive pot wall

Methodology Applied
Scientific EffectElectromagnetic coupling: Electromagnetic Induction

Data Source

PatentEP2509152B1HF filter assembly and method for varying an electromagnetic coupling strength between two cavity resonators
Publication Date: 2016.09.21 SPINNER
  • EP2509152B1 patent drawingFigure 1
  • EP2509152B1 patent drawingFigure 2a~2c
  • EP2509152B1 patent drawingFigure 3

AI summary

The arrangement has two cavity resonators coupled by a common pot wall (4). A coupling window (5) is completely enclosed by an electrically conductive material (6). A coupling unit (7) with a variably adjustable capacitance is inserted in the window. An electrically conductive bar element (8) is electrically conductively connected with the material by bar element ends (10, 11) on both sides. Finger elements (12, 13) are fastened at the bar element for electrically insulating the bar element so that the finger elements are rotatably mounted around a rotational axis coinciding a bar axis (9). An independent claim is also included for a method for varying an electromagnetic coupling strength between the two cavity resonators.