Microwave Circulator Expandable Centring Rings

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Solution Overview

Problem

Conventional microwave circulators experience discontinuities and distortions in their transfer function due to minute changes in the internal electromechanical grounding structure, caused by differential thermal expansion, manufacturing tolerances, and mechanical contact inconsistencies, leading to 'glitches' that affect signal routing.

Innovation Solution

A microwave circulator design featuring an outer metal housing with a cavity containing magnets and an annular centring arrangement of expandable austenitic stainless steel rings with inclined faces, ensuring intimate contact with the housing and reducing mechanical stress, along with integrally formed ports and a magnetic material housing to maintain a stable magnetic field.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional circulators use separate components with mechanical connections for grounding, then assembly is easier, but the grounding structure becomes unstable and prone to glitches due to thermal expansion and manufacturing tolerances

Engineering Contradiction:
Improveassembly easeVSAvoidgrounding stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent merges the grounding ring and centring arrangement into a single integrated component. The grounding ring is formed as one piece with the centring features, eliminating separate mechanical connections and ensuring stable electrical contact with the housing while maintaining ease of assembly as a single component.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The grounding ring serves multiple functions simultaneously: it provides electrical grounding, centring of the cavity contents, and mechanical support. This multi-functional design eliminates the need for separate components while improving reliability through a unified structure.

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

2Manufacturing precision

If rigid centring structures are used, then manufacturing precision is easier to achieve, but thermal expansion differences cause grounding instability and glitches

Engineering Contradiction:
Improvecentring precisionVSAvoidgrounding continuity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The grounding ring is designed with elastic properties that allow it to deform slightly under thermal stress. This parameter change enables the structure to accommodate differential thermal expansion between different materials while maintaining continuous electrical contact and stable centring.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The grounding ring incorporates flexible elastic elements that can deform to accommodate thermal expansion differences. This flexibility maintains reliable electrical grounding and centring precision across temperature variations without causing glitches.

Inventive Principle:
Principle #30Flexible shells and thin films

3Device complexity

If non-expandable rings are used for centring, then the structure is simpler, but intimate contact with housing walls cannot be ensured, leading to grounding interruptions

Engineering Contradiction:
Improvecentring structure complexityVSAvoidelectrical contact integrity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The grounding ring is designed to be expandable rather than rigid. It can dynamically adjust its dimensions to achieve intimate contact with the housing walls, ensuring continuous electrical grounding without requiring complex adjustment mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The expandable grounding ring utilizes thermal expansion principles to maintain contact with the housing walls. As temperature changes, the ring expands or contracts to ensure continuous electrical contact, preventing grounding interruptions while maintaining structural simplicity.

Inventive Principle:
Principle #37Thermal expansion

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 provides a high-integrity continuous electrical earth path, effective EMI performance, and minimizes signal leakage, significantly reducing glitches by stabilizing the electromechanical grounding structure and maintaining a consistent magnetic field.

Implementation Method 1

the second ring is expandable and is arranged to form intimate contact with the internal walls of the metal housing, when a force is applied to urge the centring arrangement along the cavity

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

an annular centring arrangement of expandable austenitic stainless steel rings with inclined faces, ensuring intimate contact with the housing and reducing mechanical stress, along with integrally formed ports and a magnetic material housing to maintain a stable magnetic field

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP2131442B1Microwave circulators
Publication Date: 2013.09.25 SMITHS GROUP PLC
  • EP2131442B1 patent drawingFigure 1~2
  • EP2131442B1 patent drawingFigure 3
  • EP2131442B1 patent drawingFigure 4~5

AI summary

A microwave circulator having an outer metal housing with a cavity containing at least one magnet and an annular centring arrangement interposed between the outside of the magnet and the cavity. The centring arrangement includes first and second solid metal rings, the two rings having cooperating inclined faces arranged such that when a force is applied to urge the centring arrangement along the cavity, one ring is displaced outwardly into intimate contact with the inside of the cavity.