NFC BASED WIRELESS CHARGING SYSTEM

Wireless battery charging, state-of-the-art

Why to charge wirelessly?• Easy-to-use charging facility• Avoiding external galvanic contacts that can be

unreliable or impractical Wireless Power Consortium (http://www.wirelesspowerconsortium.com/) has released a specification (Qi 1.0) for wireless charging of mobile handsets

Wireless battery charging, state-of-the-art

• Charging power up to 5 W (the main target application is mobile handsets)

• Inductive coupling, operating frequency 110 - 205 kHz commercial products with proprietary wireless charging

• e.g. electric toothbrushes• challenge: different approaches, versatility

Wireless battery charging, state-of-the-art

NFC-enabled wireless charging– technical baseline

• The main issue of NFC-enabled wireless charging is combining controllable wireless power transfer and NFC communication into the same implementation with shared antennas and communication channels.

• Similarly to wireless charging technologies, NFC is by construction:

NFC-enabled wireless charging– technical baseline

• based on inductive coupling between loop antennas, and

• capable of simultaneous power transfer (powering of passive tags) and bidirectional

• communication between the devices • However, the power transfer level of current

NFC implementations is much lower than needed in charging of typical mobile devices.

Requirements/challenges for thetechnical implementation

• On RF level, the NFC implementations have to be amended so that the NFC interface can transmit enough power to a compatible receiver and receive power from a compatible power transmitter with good efficiency

• On protocol level, the charging power transmission has

to feature continuous carrier generation and charging management based on message exchange between the charger device and the device to be charged.

Requirements/challenges for thetechnical implementation

• In contrast to conventional NFC interactions, close and long-lasting proximity between

• the transmitter and the receiver is needed, which also affects the mechanical and

• usability design of the charger device and the device to be charged.

• The amendments have to be made without major cost impacts and by retaining the

• NFC-compatibility without compromising NFC communication performance

EX OF POTENTIAL USE CASES

Wireless charging of small NFC enableddevices

EX OF POTENTIAL USE CASES

Delaying out of battery status ofmobile handsets

BENEFITS

• More compact and cost efficient wireless charging interface for small NFC-enabled portable devices

• More pervasive charger infrastructure (based on existing NFC devices) with reduced costs (no dedicated chargers)

• Extending battery discharging time of mobile handsets

BENEFITS

• Convenient overnight charging facility of mobile handsets

• Possibility to integrate NFC-based service to charging applications

• Benefits of 13.56 MHz over lower operating frequencies typically used in wireless charging

• Lighter antennas• Higher frequency reduces parasitic heating of

metallic stray objects

BUSINESS OPPORTUNITIES

Standardized NFC charging provides opportunity to NFC community members to

• create new applications and business models in top of the future NFC infrastructure,

• join the ”heating” market of wireless charging.

BUSINESS OPPORTUNITIES

The charging feature will:• boost the penetration of NFC especially to small

devices such as wrist units,headsets, remote controllers, mouses, sensors etc.

• produce added value to NFC-enabled mobile handsets by auxiliary charging via their NFC interface

• enable totally new NFC products related to wireless charging.

Business opportunities

• The resulting added value of NFC-enabled products increases public interest towards NFC.

• Increased revenue for NFC technology, device and application vendors.

CONCLUSION

• The relatively high (13.56 MHz) operating frequency of NFC (compared to the WPC Qi 110 - 205 kHz) favors use cases with relatively low charging power level.

• Still, charging power levels over 1 W are possible with close proximity between the antennas even within the RF field strength limit of the current NFC specification

CONCLUSION

• NFC-enabled charging will be rather a completing than a competing technology to WPC Qi specification.

• NFC-compatibility won't increase the power level or improve the power efficiency.

• NFC-compatibility will improve the compactness and cost-efficiency of the entire implementation (more detailed lists of benefits after examples of potential use cases).

THANK YOU