MIMO Antenna Dual-Split Ring Isolation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

MIMO antenna systems face challenges in miniaturization due to mutual coupling between antenna ports, which degrades communication characteristics and requires spacing between monopole antennas with a metal wire, limiting their size reduction.

Innovation Solution

A MIMO antenna device utilizing a dual-split ring structure with a bridge line and L-shaped matching circuits, allowing for miniaturization by eliminating the need for spacing between antennas and enhancing isolation between antenna ports through a multi-layered conductor configuration with metal vias and split portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two monopole antennas are spaced apart with a metal wire to eliminate mutual coupling, then isolation between antenna ports is improved, but the overall antenna size increases

Engineering Contradiction:
Improveisolation between antenna portsVSAvoidantenna device size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent combines two monopole antennas into a single integrated structure where they share a common ground electrode and are formed on the same substrate. The antennas are electrically connected through a coupling portion that integrates the feed lines, eliminating the need for separate metal wire bridges while maintaining isolation between antenna ports.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes the substrate plane and vertical layering to achieve antenna separation. Instead of spacing antennas apart in three-dimensional space with metal wires, the invention uses the two-dimensional substrate surface and multi-layer conductor configuration to provide isolation while keeping the overall device footprint small.

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

2Volume of moving object

If multiple antenna elements are integrated on a substrate to reduce size, then miniaturization is achieved, but mutual coupling between antenna ports increases

Engineering Contradiction:
Improveantenna device sizeVSAvoidisolation between antenna ports
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent introduces a coupling portion as an intermediary structure between the two monopole antennas. This coupling portion includes feed lines that are configured to control current distribution and minimize mutual coupling effects, allowing close integration of antennas while maintaining port isolation through electromagnetic field management.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes geometric parameters of the antenna structure including the dimensions and positioning of ground electrodes, feed lines, and conductor traces. By adjusting these parameters, the invention achieves miniaturization while controlling mutual coupling through impedance matching and current path optimization.

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 achieves a compact MIMO antenna design with effective isolation between antenna ports, maintaining communication efficiency and resonance within the desired frequency range, as demonstrated by S-parameter and emission efficiency graphs.

Implementation Method 1

a plurality of metal vias 8 for electrically connecting the first conductor layer 2a and the second conductor layer 2b through the dielectric layer 10

Methodology Applied
Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

A MIMO antenna device utilizing a dual-split ring structure with a bridge line and L-shaped matching circuits, allowing for miniaturization by eliminating the need for spacing between antennas and enhancing isolation between antenna ports

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP3007274B1MIMO antenna device
Publication Date: 2019.08.14 NEC CORP
  • EP3007274B1 patent drawingFigure 1
  • EP3007274B1 patent drawingFigure 2
  • EP3007274B1 patent drawingFigure 3

AI summary

The MIMO antenna device of the present invention includes a first conductor layer having a first opening portion, a first feed line and a second feed line. Each of the first feed line and the second feed line crosses the first opening portion, has a connection point with a first opening edge of the first opening portion, and feeds power to the first conductor layer at the connection point, wherein the first conductor layer includes a first split portion and a second split portion at the first opening edge. The first split portion and the second split portion are cut up to a conductor edge of the first conductor layer. Thus, the MIMO antenna device which is small in size and securing isolation between antenna ports is realized.