Partial Dielectric Loaded Septum Polarizer for Compact Arrays

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Solution Overview

Problem

Conventional waveguide polarizers are too large and unsuitable for compact, wide-bandwidth antenna arrays with closely packed radiating elements, and septum polarizers face limitations in bandwidth and grating sidelobe restrictions.

Innovation Solution

A partially dielectrically loaded septum polarizer is used, comprising a conductive septum and a dielectric insert with a shaped edge, which converts signals between dual polarization states in a common waveguide to orthogonal polarization components in individual waveguides, enabling compact, wide-bandwidth operation while suppressing grating lobes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a conventional waveguide polarizer is used, then the polarizer can convert signals between dual circular polarization states, but the polarizer is too large and bulky for closely packed antenna arrays

Engineering Contradiction:
Improvepolarizer sizeVSAvoidpolarization conversion performance
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The polarizer is divided into multiple sections along the waveguide, with each section containing a dielectric insert and conductive septum. This segmentation allows the polarizer to achieve the required polarization conversion function while reducing the overall volume and enabling compact integration into antenna arrays.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses composite structures combining dielectric materials with conductive septa within waveguide sections. This composite approach enables compact polarization conversion by leveraging the complementary properties of dielectric loading (for bandwidth extension) and conductive septa (for polarization separation), achieving both size reduction and performance maintenance.

Inventive Principle:
Principle #40Composite materials

2Volume of moving object

If a septum polarizer is used to reduce size, then the polarizer becomes more compact, but the bandwidth is limited and grating sidelobe restrictions occur at high frequencies

Engineering Contradiction:
Improvepolarizer sizeVSAvoidbandwidth
Core Design Contradiction:
Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

Different sections of the polarizer have locally optimized characteristics - some sections use dielectric inserts to extend bandwidth at lower frequencies, while other sections use conductive septa for effective polarization separation. This local optimization across different regions enables the overall device to achieve both compactness and wide bandwidth adaptability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention varies key parameters including dielectric constant values, insert dimensions, and septum geometries across different frequency optimization zones. By changing these parameters locally, the polarizer achieves broadband operation from L-band to Ka-band while maintaining compact size and avoiding grating sidelobe issues through careful parameter selection.

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 solution provides a compact, high-performance antenna array capable of efficient signal conversion across a wide frequency range without grating lobes, improving transmission at both high and low frequencies.

Implementation Method 1

a dielectric insert. The dielectric insert includes a first dielectric portion which partially fills the polarizer section, partially dielectrically loading the polarizer section

Methodology Applied
Scientific EffectDielectric loading: Dielectric

Implementation Method 2

The conductive septum and the dielectric portion are arranged to convert a signal between a polarized state in the first common waveguide and a first polarization component in the second waveguide and a second polarization component in the third waveguide

Methodology Applied
Scientific EffectPolarization conversion: Polarisation

Data Source

PatentEP3098899B1Partial dielectric loaded septum polarizer
Publication Date: 2022.02.09 VIASAT INC
  • EP3098899B1 patent drawingFigure 1
  • EP3098899B1 patent drawingFigure 2A
  • EP3098899B1 patent drawingFigure 2B

AI summary

In an example embodiment, a waveguide device comprises: a first common waveguide; a polarizer section, the polarizer section including a conductive septum dividing the first common waveguide into a first divided waveguide portion and a second waveguide divided portion; a second waveguide coupled to the first divided waveguide portion of the polarizer section; a third waveguide coupled to the second divided waveguide portion of the polarizer section; and a dielectric insert. The dielectric insert includes a first dielectric portion partially filling the polarizer section. The conductive septum and the dielectric portion convert a signal between a polarized state in the first common waveguide and a first polarization component in the second waveguide and a second polarization component in the third waveguide.