Circularly Polarized Wave Generator Protrusion Envelope

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Solution Overview

Problem

Conventional circularly polarized wave generators face challenges in achieving preferable frequency characteristics of the passing phase difference between polarized waves over a wide band while maintaining a reduced axial length, as varying protrusion heights either reduces the absolute phase difference or increases the number of stages, making it difficult to balance both frequency characteristics and axial length.

Innovation Solution

The circularly polarized wave generator employs a configuration with both first and second protrusions arranged in a rectangular waveguide, where the first protrusions are orthogonal to the axial direction and the second protrusions run along the axial direction, forming a smooth quadratic or cubic Cos curve, allowing for increased phase difference between V-polarized and H-polarized waves without increasing the waveguide's axial length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heights of the protrusions are gradually varied to achieve preferable frequency characteristics over a wide band, then the frequency characteristics are improved, but the axial length of the waveguide increases

Engineering Contradiction:
Improvefrequency characteristics of passing phase differenceVSAvoidaxial length of waveguide
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The waveguide is divided into multiple stages with protrusions arranged at predetermined intervals. Each stage contributes to the overall phase difference, allowing the total phase difference to accumulate across stages rather than requiring a single long protrusion structure. This segmentation enables achieving the desired phase difference characteristics while controlling the axial length.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heights of individual protrusions are varied locally to form envelope curves (quadratic or cubic Cos curves). This local variation in protrusion heights creates the necessary phase difference characteristics at each stage, while the overall arrangement of stages controls the axial length. The envelope curves provide smooth transitions that maintain preferable frequency characteristics.

Inventive Principle:
Principle #3Local quality

2Length of moving object

If the axial length is reduced, then the waveguide becomes more compact, but the heights of the protrusions must be sharply varied making it difficult to realize preferable frequency characteristics

Engineering Contradiction:
Improveaxial length of waveguideVSAvoidfrequency characteristics of passing phase difference
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The envelope of protrusion heights follows smooth dynamic curves (quadratic or cubic Cos curves) rather than sharp transitions. This dynamic variation allows the heights to change gradually across stages, maintaining preferable frequency characteristics even when the overall axial length is reduced. The smooth curves ensure continuous phase transitions that preserve frequency response quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The solution moves from varying protrusion heights continuously along a single axial dimension to varying heights across multiple discrete stages arranged in sequence. This dimensional approach allows the phase difference to accumulate across stages while keeping each stage compact, achieving the desired frequency characteristics without requiring a long continuous axial length.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration achieves preferable frequency characteristics of the passing phase difference over a wide band by enhancing the phase difference between polarized waves, reducing the frequency deviation, and allowing for a larger absolute phase difference without increasing the waveguide's axial length, thus optimizing performance in the microwave and millimeter wave bands.

Implementation Method 1

a passing phase difference occurs between two linearly polarized waves (V-polarized wave, H-polarized wave) input to the circularly polarized wave generator that are orthogonal to each other, and the linearly polarized waves are converted into a circularly polarized wave

Methodology Applied
Scientific EffectPhase difference between polarized waves:

Data Source

PatentEP3151334B1Circularly polarized wave generator
Publication Date: 2019.05.22 MITSUBISHI ELECTRIC CORP
  • EP3151334B1 patent drawingFigure 1~2
  • EP3151334B1 patent drawingFigure 3~4(b)
  • EP3151334B1 patent drawingFigure 5~7

AI summary

A circularly polarized wave generator includes a rectangular hollow waveguide (1), a plurality of first protrusions (2) that are provided on one pair of opposing wall surfaces in the waveguide (1), have longitudinal directions orthogonal to an axial direction of the waveguide (1), and are arranged at intervals along the axial direction, and a plurality of second protrusions (3) that are provided between the first protrusions (2) on the wall surfaces and are arranged with longitudinal directions thereof running along the axial direction.