Antenna Phase Shifting for Wireless Interference Reduction

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Solution Overview

Problem

In mobile cellular telephones with multiple antennas, electromagnetic coupling and interference increase as antenna distance decreases, leading to inefficiency or inoperability when the antenna arrangement must fit into a small space.

Innovation Solution

The use of reactive components with variable impedances and a controller to shift the phase of signals between antennas, allowing for destructive interference and reducing coupling, enabling efficient operation even when antennas are in close proximity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the distance between antennas is reduced to fit into a small space, then the device size is reduced, but electromagnetic coupling and interference between antennas increases

Engineering Contradiction:
Improvedevice sizeVSAvoidelectromagnetic interference
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

A reactive component is introduced as an intermediary element between the two antennas. This reactive component couples to both antennas and provides a controlled electromagnetic path that enables destructive interference of the coupled signals, thereby reducing the harmful electromagnetic interference while allowing the antennas to be positioned in close proximity for compact device design

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If reactive components with variable impedances are added to reduce electromagnetic coupling, then interference is reduced, but device complexity increases

Engineering Contradiction:
Improveelectromagnetic couplingVSAvoidantenna arrangement complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The reactive component is designed with variable impedance characteristics that can be dynamically adjusted. By changing the impedance parameter of the reactive component, the system can optimize the destructive interference effect for different operating conditions and frequency bands, effectively reducing electromagnetic coupling while managing the added complexity through controlled parameter variation

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

This solution effectively isolates antennas across overlapping frequency bands, reducing electromagnetic interference and allowing for compact antenna arrangements without impacting performance, thus enhancing device efficiency and size reduction.

Implementation Method 1

at least the first reactive component is configured to have an impedance that shifts the phase of a first signal, in the second operational resonant frequency band, received from the first antenna

Methodology Applied
Scientific EffectPhase shift:

Implementation Method 2

the first signal and the second signal at least partially destructively interfere with one another at the first junction

Methodology Applied
Scientific EffectDestructive interference: Interference

Data Source

PatentEP2577799B1Apparatus, methods, computer programs and computer readable storage mediums for wireless communication
Publication Date: 2015.09.23 NOKIA TECHNOLOGIES OY
  • EP2577799B1 patent drawingFigure 1
  • EP2577799B1 patent drawingFigure 2
  • EP2577799B1 patent drawingFigure 3

AI summary

An apparatus comprising: a first port configured to receive signals from a transceiver and to receive a first antenna, the first antenna being configured to operate in a first operational resonant frequency band; a second port configured to receive signals from a transceiver and to receive a second antenna, the second antenna being configured to operate in a second operational resonant frequency band; a first reactive component coupled to the first port; a second reactive component coupled to the first reactive component at a first junction and to the second port, wherein at least the first reactive component is configured to have an impedance that shifts the phase of a first signal, in the second operational resonant frequency band, received from the first antenna, and the second reactive component is configured to have an impedance that shifts the phase of a second signal, in the second operational resonant frequency band, received from the transceiver, so that the first signal and the second signal at least partially destructively interfere with one another at the first junction.