Rectangular-to-Circular Waveguide Transition Filter Card

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Circular waveguides in microwave communication systems suffer from signal loss due to higher-order modes causing resonances, and mechanical mismatches between rectangular and circular waveguides lead to additional signal loss and reflections.

Innovation Solution

A rectangular-to-circular waveguide transition system incorporating a filter card with a substrate of woven glass cloth impregnated with thermosetting resin and a resistance film, positioned across the waveguide to suppress high-order modes and attenuate unwanted wave energy, thereby reducing signal loss and resonances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a circular waveguide is used to transmit TE11 signal, then signal loss is reduced, but higher-order modes cause resonances and unexpected signal loss

Engineering Contradiction:
Improvesignal lossVSAvoidsignal stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

A filter card is introduced as an intermediary component within the circular waveguide to suppress higher-order modes. The filter card acts as a mediator that allows the fundamental TE11 mode to pass while blocking higher-order modes that cause resonances, thus resolving the contradiction between low signal loss and signal stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The filter card changes the electromagnetic field distribution parameters within the waveguide by strategically positioned conductive elements that create specific impedance variations. This parameter change suppresses higher-order modes while maintaining fundamental mode transmission, addressing both signal loss and stability concerns.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a rectangular-to-circular waveguide transition is used to connect antennas and processing equipment, then compatibility is improved, but mechanical mismatch causes resonances and signal loss

Engineering Contradiction:
Improvewaveguide compatibilityVSAvoidsignal integrity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The filter card serves as an intermediary component in the rectangular-to-circular waveguide transition, compensating for mechanical mismatches. It acts as a buffer that suppresses resonances caused by alignment tolerances between rectangular and circular waveguide sections, maintaining signal integrity while enabling compatibility between different waveguide types.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If mechanical tolerance is increased to allow easier assembly, then ease of manufacture is improved, but mechanical mismatch causes resonances

Engineering Contradiction:
Improveassembly toleranceVSAvoidresonances
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The filter card converts the harmful effect of mechanical mismatches and resonances into a controlled impedance variation that actively suppresses higher-order modes. What would normally be a harmful resonance condition is transformed into a beneficial filtering mechanism that improves overall system performance while allowing easier assembly.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 effectively suppresses high-order modes and reduces signal loss by attenuating unwanted wave energy, improving the efficiency and reliability of microwave communication systems while allowing for greater mechanical tolerance and compact design.

Implementation Method 1

The filter card may be configured to suppress high-order modes, and/or attenuates at least some wave energy

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP2622677B1Systems and methods of a rectangular-to circular waveguide transition
Publication Date: 2018.12.26 AVIAT NETWORKS INC
  • EP2622677B1 patent drawingFigure 1
  • EP2622677B1 patent drawingFigure 2~3b
  • EP2622677B1 patent drawingFigure 3c~3e

AI summary

Systems and methods for a filtering wave energy using a rectangular-to-circular waveguide transition are discussed herein. An exemplary system comprises a rectangular-to- circular waveguide transition and a filter card. The rectangular-to-circular waveguide transition may include a front section and a back section opposite the front section, the rectangular-to-circular waveguide transition defining a circular hole extending from the front section of the rectangular-to-circular waveguide transition through the back section, the rectangular-to-circular waveguide transition further having a first arcuate region on the face of the transition, the first arcuate region defining a first cavity extending from the circular hole through the first arcuate region, the rectangular-to-circular waveguide transition also having a second arcuate region defining a second cavity opposite the first cavity, the second cavity extending from the circular hole through the second arcuate region. The filter card may be configured to be placed across the circular hole of the rectangular-to-circular waveguide transition.