Antenna Device with Impedance Matching Circuit for Coupling Cancellation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Portable wireless terminals face degradation in antenna performance due to coupling between antenna elements operating in the same or different frequency bands, which is not effectively addressed by existing configurations that assume operation within a single frequency band.

Innovation Solution

An antenna device is configured with a first and second antenna element, each operating in specific frequency bands, connected by a connection circuit to cancel mutual coupling impedance in the same frequency band, and equipped with a cutoff circuit to manage power and increase operation volume in different frequency bands, using impedance matching circuits for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If multiple antenna elements are disposed close to each other to increase integration density, then miniaturization of terminal is achieved, but coupling between antenna elements causes degradation of antenna performance

Engineering Contradiction:

Improveterminal sizeVSAvoidantenna performance

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

A connection circuit is introduced as an intermediary between antenna elements to cancel mutual coupling impedance. The connection circuit includes impedance matching components that compensate for the harmful coupling effects, allowing antenna elements to be placed closer together without performance degradation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The impedance characteristics of the connection circuit are optimized to match the coupling impedance between antenna elements. By adjusting the impedance parameters of the connection circuit, the mutual coupling is canceled, enabling compact antenna arrangements while maintaining performance.

Inventive Principle:

Principle #35Parameter changes

2Area of stationary object

If antenna elements operating in different frequency bands are disposed close to each other, then integration density is increased, but coupling occurs between different frequency bands causing performance degradation

Engineering Contradiction:

Improveantenna arrangement densityVSAvoidfrequency band isolation

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The frequency bands are segmented and managed separately through frequency-specific connection circuits. Each antenna element operating in different frequency bands is equipped with dedicated impedance matching circuits that operate only at their respective frequencies, preventing cross-band coupling.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Frequency-selective connection circuits act as intermediaries that allow signals at specific frequencies to pass while blocking other frequencies. This enables close placement of multi-band antenna elements while maintaining isolation between different frequency bands.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If connection circuits are added to cancel mutual coupling impedance, then coupling between same frequency band antennas is reduced, but device complexity increases

Engineering Contradiction:

Improvecoupling reductionVSAvoidcircuit configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The connection circuit performs multiple functions simultaneously: it provides impedance matching for the antenna element and cancels mutual coupling impedance. By combining these functions in a single circuit structure, the overall device complexity is minimized while achieving the desired coupling reduction.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The connection circuit is designed to serve multiple antenna elements and multiple frequency bands through universal impedance matching topologies. This multi-functional approach reduces the need for separate circuits for each antenna element, thereby reducing overall device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 high-efficiency antennas with reduced coupling in the same frequency band and increased operation volume in different frequency bands, improving antenna characteristics and enabling miniaturization of portable wireless terminals.

Implementation Method 1

the first connection circuit is configured to cancel out mutual coupling impedance between the first antenna element and the second antenna element in the first frequency band

Methodology Applied

Scientific EffectMutual coupling impedance cancellation: Electromagnetic Induction

Implementation Method 2

a second frequency band cutoff circuit for electrical cutoff in the second frequency band

Methodology Applied

Scientific EffectFrequency band cutoff: Filter (electronic)

Data Source

PatentUS9444150B2Antenna device and portable wireless terminal equipped with same

Publication Date: 2016.09.13 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A first connection circuit (108) is adjusted to cancel out mutual coupling impedance occurring between a first antenna element (106) in a first frequency band and a second antenna element (107) in a second frequency band, and reduces a degradation occurring due to the coupling between the antenna elements. A second frequency band cutoff circuit (111) for the second frequency band is provided between the first antenna element (106) and the first feeding portion (104).