Vehicle NFC Antenna Characterization for Mobile Device Type Detection
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Solution Overview
Problem
Existing 'hands free' vehicle access systems using NFC technology face challenges in distinguishing between mobile phones and tags, which affects antenna configuration and communication quality, and in determining the approach mode of mobile devices, leading to inefficient data transfer and application triggering.
Innovation Solution
A method that characterizes mobile devices by measuring the evolution of voltage across the terminals of the primary NFC antenna, allowing the system to differentiate between mobile phones and tags, and determine dynamic or static approach modes, thereby optimizing antenna configuration and communication content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the system uses a single primary NFC antenna for both tags and mobile phones, then the device complexity is reduced, but the communication quality and antenna configuration optimization deteriorates
Solution Approach 1:
The patent implements dynamic antenna configuration by measuring voltage evolution over time periods to detect mobile device type and approach mode, then adjusting antenna parameters accordingly. This allows a single antenna to adapt its characteristics dynamically rather than requiring multiple fixed antennas, resolving the contradiction between system complexity and communication quality.
Solution Approach 2:
The system changes antenna parameters (such as impedance, resonant frequency, or coupling coefficient) based on detected device characteristics. By measuring voltage evolution and determining device type and approach mode, the system optimizes antenna parameters in real-time, maintaining high communication quality without increasing physical antenna count.
2Measurement precision
If the system continuously monitors voltage to accurately characterize mobile devices, then the measurement precision improves, but the power consumption increases
Solution Approach 1:
The patent employs periodic voltage measurements at specific time periods rather than continuous monitoring. By measuring voltage at discrete intervals and analyzing the evolution pattern, the system achieves accurate device characterization while minimizing power consumption through pulsed measurement operation.
Solution Approach 2:
The system performs preliminary voltage measurements to detect the presence and type of mobile device before initiating full communication protocols. This preliminary characterization allows the system to prepare appropriate communication parameters in advance, improving overall measurement precision while avoiding continuous high-power operation.
3Productivity
If the system optimizes antenna configuration based on mobile device type, then the communication efficiency improves, but the device complexity increases
Solution Approach 1:
The system automatically characterizes mobile devices by analyzing voltage evolution patterns and self-adjusts antenna configuration without user intervention. This self-service approach enables optimized communication efficiency while keeping the user interface simple, as the system autonomously determines device type and adapts parameters accordingly.
Solution Approach 2:
The system measures voltage evolution across time periods, uses this feedback to determine mobile device type and approach mode, and then adjusts antenna configuration based on this information. This closed-loop feedback mechanism enables efficient data transfer while maintaining manageable system complexity through automated decision-making algorithms.
4Adaptability or versatility
If the system uses multiple primary NFC antennas for different functions, then the adaptability improves, but the device complexity increases
Solution Approach 1:
The patent makes a single primary NFC antenna universal by enabling it to serve multiple functions through dynamic reconfiguration. The same antenna is used for both tag detection and mobile phone communication, with its parameters adjusted based on the detected device type. This eliminates the need for separate dedicated antennas while maintaining full adaptability for different communication scenarios.
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
Improves communication quality and reduces power consumption by accurately configuring the antenna and selecting appropriate communication modes based on the type and approach mode of the mobile device, enabling efficient data transfer and application triggering.
Implementation Method 1
a primary antenna (13) on board a motor vehicle (10), in particular a NFC communication antenna, which is intended to communicate with a secondary antenna (21) of a mobile device (20) of indeterminate type, in particular a tag or a mobile phone, approaching the motor vehicle (10) in an indeterminate approach mode, and generating a voltage across its terminals
Data Source
AI summary
A method for characterizing, by way of at least one primary antenna (13, 31) on board a motor vehicle (10), a mobile device (20) of indeterminate type comprising a secondary antenna (21) of indeterminate size, approaching said motor vehicle (10) in an indeterminate approach mode, said primary antenna (13, 31) being intended to communicate with the secondary antenna (21) of the mobile device (20), and generating a voltage (V) across its terminals, the voltage being linked to an on-board system (11) of the motor vehicle (10), the invention proposes that the method of characterization comprises the following steps:step 1: measurement by the on-board system (11) of the voltage across the terminals of the primary antenna (13, 31), over a series of predetermined time periods,step 2: computation of a voltage difference for each predetermined time period,step 3: comparison of the voltage difference with a value previously stored in the memory,step 4: if the voltage difference is positive, then the mobile device (20) is of dielectric type, otherwise if it is negative, it is of metallic type,step 5: if the voltage difference is zero over a predetermined time period above a threshold, then the mobile device (20) is in static approach mode, otherwise it is in dynamic approach mode.