Dielectric Waveguide PTFE Permittivity Attenuation

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Solution Overview

Problem

Dielectric waveguides for millimeter and submillimeter waves face high attenuation due to the use of metallic core wires, which limits their transmission efficiency, and existing polytetrafluoroethylene (PTFE) materials have not effectively balanced high permittivity with low loss tangent for improved signal confinement.

Innovation Solution

A dielectric waveguide is developed using a PTFE molded article with a permittivity of 2.05 or higher and a loss tangent of 1.20 × 10^-4 or lower, combined with a dielectric layer of lower permittivity, creating a significant permittivity difference to enhance electromagnetic wave confinement and transmission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metallic core wire is used in dielectric waveguide, then the waveguide can transmit microwaves, but attenuation becomes too high for millimeter waves and submillimeter waves

Engineering Contradiction:
Improvetransmission capabilityVSAvoidattenuation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention extracts and removes the metallic core wire from the waveguide structure, replacing it entirely with dielectric materials. This elimination of metal components directly addresses the high attenuation problem for millimeter and submillimeter waves while maintaining transmission capability through dielectric waveguide modes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention substitutes the metallic conduction mechanism with a dielectric waveguide mechanism. Instead of relying on metal surfaces to guide electromagnetic waves, the system uses dielectric materials with specific permittivity characteristics to confine and guide the waves, thereby reducing attenuation at higher frequencies.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of energy

If polytetrafluoroethylene is used as insulating coating layer material, then dielectric loss is reduced, but balancing electric characteristics with processability requires controlled heating treatment

Engineering Contradiction:
Improvedielectric lossVSAvoidprocessability
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The invention changes the heating treatment parameters of polytetrafluoroethylene to achieve optimal balance between electric characteristics and processability. By controlling the heating temperature and duration, the patent optimizes the crystallinity and physical properties of PTFE to simultaneously reduce dielectric loss and maintain manufacturability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses polytetrafluoroethylene as a composite dielectric material in the waveguide structure, leveraging its low dielectric loss properties. The material is integrated into the dielectric waveguide design to minimize energy attenuation while maintaining structural integrity and processability through controlled thermal treatment.

Inventive Principle:
Principle #40Composite materials

3Reliability

If permittivity difference between center portion and outer layer is increased, then electromagnetic wave confinement effect is enhanced, but obtaining polytetrafluoroethylene material with both high permittivity and low loss tangent becomes difficult

Engineering Contradiction:
Improvesignal confinementVSAvoidloss tangent
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention applies local quality by creating a dielectric waveguide structure with spatially varying permittivity characteristics. The center portion and outer layer use different dielectric materials or configurations to achieve the desired permittivity difference for effective wave confinement, while each region is optimized to maintain low loss tangent properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention employs composite dielectric materials to achieve both high permittivity and low loss tangent simultaneously. By combining materials with complementary properties or using graded composite structures, the patent overcomes the difficulty of finding single materials that satisfy both high signal confinement and low energy loss requirements.

Inventive Principle:
Principle #40Composite materials

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 achieves high transmission efficiency for millimeter and submillimeter waves by increasing the permittivity difference between the center and outer layers, reducing attenuation, and maintaining low loss tangent, thereby improving the overall performance of dielectric waveguides.

Implementation Method 1

a polytetrafluoroethylene molded article that has a permittivity of 2.05 or higher at 2.45 GHz or 12 GHz, a loss tangent of 1.20 × 10^-4 or lower

Methodology Applied
Scientific EffectPermittivity difference: Dielectric Permittivity

Implementation Method 2

a loss tangent of 1.20 × 10^-4 or lower

Methodology Applied
Scientific EffectLoss tangent: Dielectric Permittivity

Data Source

PatentEP3249742B1Dielectric waveguide line
Publication Date: 2021.04.28 DAIKIN INDUSTRIES LTD
  • EP3249742B1 patent drawingFigure 1~3
  • EP3249742B1 patent drawingFigure 4
  • EP3249742B1 patent drawing

AI summary

The present invention provides a dielectric waveguide having excellent transmission efficiency. The dielectric waveguide includes a polytetrafluoroethylene molded article that has a permittivity of 2.05 or higher at 2.45 GHz or 12 GHz, a loss tangent of 1.20 × 10-4 or lower at 2.45 GHz or 12 GHz, and a hardness of 95 or higher.