NFC Antenna Matching Control Circuit for Signal Quality

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Solution Overview

Problem

Mobile wireless communication devices face challenges in maintaining optimal near-field communication (NFC) signal quality due to variations in proximity environments and device orientations, leading to signal degradation and power loss, which existing technologies fail to adequately address.

Innovation Solution

A mobile wireless communications device equipped with a near-field communications (NFC) transceiver, multiple NFC antennas, and an NFC control circuit that includes an antenna switch circuit, capacitance sensing circuit, and processor, which dynamically tunes and matches the NFC antennas based on received signal strength and capacitance values to maintain effective interfacing with adjacent NFC devices, regardless of their size, and adjusts operation modes to optimize signal range and quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single NFC antenna is used in mobile devices, then the device structure remains simple, but signal quality degrades when devices are used in varying orientations or proximity conditions

Engineering Contradiction:
ImproveNFC signal qualityVSAvoidantenna system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the single NFC antenna into multiple antenna elements (first NFC antenna and second NFC antenna) positioned at different locations on the device. This segmentation allows the system to select or combine specific antenna elements based on device orientation and proximity conditions, thereby maintaining signal quality without requiring a completely complex reconfigurable single antenna system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic antenna selection and switching mechanisms that adapt the NFC antenna configuration in real-time based on detected device orientation, proximity to other devices, and signal quality metrics. The system dynamically switches between different antenna elements or combines them using techniques like electromagnetic coupling to optimize performance for current operating conditions.

Inventive Principle:
Principle #15Dynamics

2Reliability

If NFC antennas are dynamically tuned to maintain optimal signal quality, then signal range and quality improve, but power consumption increases due to continuous adjustment

Engineering Contradiction:
ImproveNFC signal rangeVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent employs feedback mechanisms where the NFC controller continuously monitors signal quality metrics, coupling strength, and communication effectiveness. Based on this feedback, the system intelligently adjusts antenna tuning parameters, switching decisions, and combining ratios. The feedback loop allows the system to maintain optimal signal range while minimizing unnecessary adjustments, thereby reducing overall power consumption compared to continuous aggressive tuning.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically changes antenna parameters such as impedance, resonant frequency, and coupling strength based on detected operating conditions. By adjusting these parameters adaptively rather than continuously, the system maintains optimal NFC signal range across varying proximity and orientation conditions while managing power consumption through intelligent parameter selection rather than constant adjustment.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple NFC antennas are used to improve signal quality in varying conditions, then NFC communication reliability improves, but the device structure and antenna configuration become more complex

Engineering Contradiction:
ImproveNFC operation in varying conditionsVSAvoidantenna configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple NFC antenna elements using electromagnetic coupling techniques where the antennas are positioned and oriented to create complementary radiation patterns. By merging the functionality of multiple antennas through controlled coupling and signal combining, the system achieves enhanced adaptability to varying device orientations and proximity conditions while avoiding the full complexity of independently controlling each antenna element in all scenarios.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent designs the multiple NFC antenna elements to serve universal functions across different operating scenarios. Rather than dedicating each antenna to specific orientations or conditions, all antenna elements are designed to be functional in multiple configurations, allowing the system to achieve versatility through intelligent selection and combination rather than specialized dedicated antennas for each condition.

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 ensures consistent and improved NFC signal quality and range by dynamically adjusting antenna settings, maintaining adequate reading distances and reducing power loss, even when devices are used in varying orientations or proximity conditions.

Implementation Method 1

a capacitance sensing circuit coupled to the plurality of NFC antennas to determine capacitance values

Methodology Applied
Scientific EffectCapacitance sensing: Capacitance

Implementation Method 2

a near-field communications (NFC) transceiver configured to generate a received signal strength based on a received signal from an adjacent NFC device

Methodology Applied
Scientific EffectElectromagnetic signal reception: Electromagnetic Induction

Data Source

PatentEP2752999B1Mobile wireless communications device including NFC antenna matching control circuit and associated methods
Publication Date: 2018.03.07 BLACKBERRY LTD
  • EP2752999B1 patent drawingFigure 1
  • EP2752999B1 patent drawingFigure 2
  • EP2752999B1 patent drawingFigure 3

AI summary

A mobile wireless communications device includes a near-field communications (NFC) transceiver, NFC antennas and an NFC control circuit. The NFC transceiver generates a received signal strength based on a received signal from an adjacent NFC device. The NFC control circuit includes an antenna switch circuit coupled between the NFC transceiver and the NFC antennas. A capacitance sensing circuit is coupled to the NFC antennas to determine capacitance values thereof. A processor operates the antenna switch circuit based upon the received signal strength and the capacitance values.