Isothermal Terminator Shape Optimization for RF Absorption

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Solution Overview

Problem

Conical RF terminators in waveguides generate thermal gradients due to their shape, leading to inefficiencies in RF absorption and reflection, which complicates their use in certain applications.

Innovation Solution

An isothermal terminator with a concave cone shape, formed by reshaping a conical terminator to minimize thermal gradients, using a method that involves graphing thermal gradients and applying a best fit function to optimize surface area for uniform heating and RF absorption, is developed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a conical shape is used for the terminator, then RF absorption is promoted and reflections are minimized, but thermal gradients are generated within the material

Engineering Contradiction:
ImproveRF absorption efficiencyVSAvoidthermal gradient
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The patent changes the geometric parameters of the terminator from a standard conical shape to a specifically designed profile (such as parabolic or other optimized curves) that modifies the distribution of RF energy absorption, thereby reducing thermal gradients while maintaining effective RF absorption

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different material properties or structural characteristics to different regions of the terminator body, creating zones with varying thermal conductivity or heat capacity that compensate for the non-uniform RF energy distribution, thus reducing overall thermal gradients

Inventive Principle:
Principle #3Local quality

2Loss of energy

If a conical shape is used for the terminator, then RF absorption is promoted, but uniform heating is not achieved

Engineering Contradiction:
ImproveRF absorption efficiencyVSAvoiduniform heating
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The patent modifies the geometric parameters of the terminator profile from a simple cone to an optimized shape (such as parabolic or custom curves) that distributes RF energy more uniformly throughout the material, achieving both effective absorption and uniform heating

Inventive Principle:
Principle #35Parameter changes

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 isothermal terminator achieves a substantially enhanced electric field distribution and uniform IR emission, reducing thermal gradients and improving RF absorption efficiency.

Implementation Method 1

the terminator is configured to react isothermally to the EM radiation being incident on the exterior surface to thereby generate a substantially enhanced electric (E) field distribution

Methodology Applied
Scientific EffectElectromagnetic radiation absorption: Absorption (EM radiation)

Implementation Method 2

with the RF radiation incident on the exterior surface such that the RF radiation is absorbed by the cone shaped terminator, infrared (IR) radiation is emitted from the interior surface

Methodology Applied
Scientific EffectInfrared radiation emission: Infrared Radiation

Data Source

PatentEP3044826B1Isothermal terminator and method for determining shape of isothermal terminator
Publication Date: 2020.06.10 RAYTHEON CO
  • EP3044826B1 patent drawingFigure 1
  • EP3044826B1 patent drawingFigure 2
  • EP3044826B1 patent drawingFigure 3

AI summary

An isothermal terminator system is provided. The isothermal terminator includes a waveguide formed to define a propagation channel through which electro-magnetic (EM) radiation is directed and a terminator including a body having an exterior surface and an interior surface opposite the exterior surface. The terminator is disposed in the propagation channel such that the EM radiation is incident on the exterior surface to raise a temperature of the body. The body is substantially isothermal with the EM radiation incident on the exterior surface.