Printed Annular Antenna Layout for Orthogonal MIMO Decoupling

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Solution Overview

Problem

Current UWB antennas for MIMO applications lack efficient designs that can provide independent control over orthogonal polarizations, limiting their ability to offer multiple input multiple output functionality with a low profile and unidirectional radiation pattern.

Innovation Solution

The design incorporates a conductive annulus with two orthogonal conductive lands and waveguides that excite different characteristic current modes, allowing for independent control of these modes through magnetic coupling, enabling two transmit/receive channels in a single antenna structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single antenna structure is used for MIMO applications, then device complexity is reduced, but the ability to provide independent control over orthogonal polarizations deteriorates

Engineering Contradiction:
Improveantenna structureVSAvoidindependent control over orthogonal polarizations
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The single antenna structure is segmented into two independent feeding structures, each capable of exciting a different orthogonal polarization mode. The first feeding structure with first and second conductive elements excites a first polarization mode, while the second feeding structure with third and fourth conductive elements excites a second orthogonal polarization mode. This segmentation allows independent control of each polarization channel within a unified antenna body, resolving the contradiction between structural simplicity and functional versatility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The antenna structure is designed to perform multiple functions simultaneously - it can transmit and receive signals on two orthogonal polarizations using a single radiating element. The conductive annulus with its four feeding points serves both as a single integrated antenna structure and as two separate polarization-controlled antennas, achieving multi-functionality without increasing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Stability of the object's composition

If orthogonal polarization modes are coupled, then radiation pattern is improved, but decoupling between modes deteriorates

Engineering Contradiction:
Improveradiation patternVSAvoiddecoupling between modes
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

Different regions of the conductive annulus are assigned different functions to achieve both coupled radiation and decoupled modes. The first and second conductive elements in the first diameter create a first polarization mode with specific radiation characteristics, while the third and fourth conductive elements in the second diameter create an orthogonal polarization mode. Each local region is optimized for its specific polarization function, allowing the overall structure to maintain both stable radiation patterns and mode decoupling.

Inventive Principle:
Principle #3Local quality

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 provides a low-profile UWB antenna with improved decoupling between orthogonal modes, enhancing the antenna's MIMO functionality and radiation pattern, achieving efficient multi-channel communication.

Implementation Method 1

These two wave guides can be arranged so that each one excites a different one of two orthogonal characteristic current modes of the antenna

Methodology Applied
Scientific EffectElectromagnetic coupling: Electromagnetic Induction

Data Source

PatentEP3547448B1Printed annular antenna for MIMO applications
Publication Date: 2023.09.20 SWISSCOM AG
  • EP3547448B1 patent drawingFigure 1
  • EP3547448B1 patent drawingFigure 2~3
  • EP3547448B1 patent drawingFigure 4

AI summary

An antenna is disclosed. The antenna is disposed on a planar dielectric substrate and comprises a first conductive annulus on a first surface of the substrate, a first conductive land on the first surface, wherein the first conductive land lies in a region of the surface bounded by the first conductive annulus and an edge of the first conductive land is adjacent to, and parallel to, a portion of an inward edge of the first conductive annulus, and a second conductive land provided on the first surface wherein an edge of the second conductive land is adjacent to, and parallel to, a portion of an outward edge of the first conductive annulus. A MIMO transceiver apparatus and a method of providing MIMO are also disclosed.