Wireless Power Transfer Technology - PSMA...© 2012 QUALCOMM Incorporated. All rights reserved. 4 The Resonant Receiver Nikola TESLA 1901: Resonant Magnetic Induction 1902: Wireless

© 2012 QUALCOMM Incorporated. All rights reserved. 1

Wireless Power Transfer Technology

The development of specifications that meet users’ needs

Francesco Carobolante Vice President, Engineering Thursday, August 9, 2012


Agenda Wireless Power Transfer Technology

Market Status & Technology Adoption

Technology Comparison

Technology Features of Flexibly Coupled Wireless Power

Understanding Wireless Power Regulations

Regulatory Requirements for Wireless Power

Qualcomm’s approach to Regulatory Compliance

Alliance for Wireless Power



The Resonant Receiver

Nikola TESLA

1901: Resonant Magnetic

Induction

1902: Wireless Energy

Transmission


System Description – Key parameters

C1

R2

L1

R1

L2

C2

r2 Rin

M

Tx Source

Rx

equivalent

load

Tx Antenna Rx Antenna

22

22

1rR

MRRin

22

221

22

2

1

1

M

rRR

rR

r

122 RRrRM

in


The Ecosystem


Easy and convenient charging of multiple devices

Colors, patterns & shapes that match décor

Streamlined, integrated device enablement

Cool, thin, portable and sleek designs

Sub-$100 total solution price points

Works with portfolio of CE devices

True wireless charging experience

Ubiquitous charging locations

What Consumers Care About

“I’d kill for no cords!”

“You can have

whatever matches

your house.”

“It would charge

automatically in the

charging zone.”

“If I don’t do anything to charge a phone, that’s the best.”

“You never have to

worry about charging

your phone again.”

“I just love

something that fits

in my briefcase.”

State of the Market


State of the Market

Tightly coupled, “Inductive” based products have been on the market since 2009

Qi specification released July 2010

Over 100 companies participating in WPC

Why hasn’t the market developed?

Wireless Power Summit 2011 on Tightly Coupled Solutions

Offer Low Flexibility

Limited application

Causes Induced heating of foreign objects

CE4A FoD Test Results on coins IN & NEAR charging field

“After a few minutes, coins reached 50°C…too hot for a

use in a vehicle.”

“Nearby test also resulted in coins getting very hot too.”

http://images.google.com/imgres?imgurl=http://www.crunchgear.com/wp-content/uploads/2009/01/samsung-logo.jpg&imgrefurl=http://www.crunchgear.com/2009/01/06/ces-rumor-samsung-quietly-releasing-a-12-inch-netbook-to-avoid-intels-wrath/&usg=__2NFleKkIlkAGNv2HZsdd06rO-wE=&h=290&w=496&sz=15&hl=en&start=2&tbnid=2pK5zIoadMicjM:&tbnh=76&tbnw=130&prev=/images?q=samsung+logo&gbv=2&hl=en


Market Forecast Information

Drop in IMS forecast from 2011 to 2012

2014 – Transition from accessory based solutions to integrated solutions occurs

2016/2017 – Loosely coupled adoption occurs at 2x the rate of tightly coupled in both years

2018 – Loosely coupled surpass tightly coupled solutions and tightly coupled continue to decline

IMS Research indicates in their latest market study:

Based upon ~1 Billion+ handsets shipped annually

Wireless Market Segments:

Mobile Phones – 88% in 2012 dropping to 74% in 2020

Tablets – obtain about 7% of the market in 2020 and continue to rise

Headsets – obtain about ~6% of the market through 2020

“Consensus is that a move to a loosely coupled solution is required” Farouk Balouchi, Analyst Pike Research


Technology Comparison


Wireless Charging Landscape

oLong Range: Far-field RF Coupling of RF energy to a device with a small receiver

antenna with device in the rf far field

Short to Medium Range: Near Field Resonance

Device is brought within near field of a low frequency Tx

antenna. RF energy couples to device with small receive

antenna where it is rectified for device charging

oShort range: Inductive Coupling Coupling of RF energy when a device with a small

receive antenna is placed on a “charging surface”

containing the transmit elements

oZero range: Conductive Mat

Current flows through the pad to a conductive adapter in

the device

Convenie

nce


Flexible vs. Tightly Coupled Solutions Key Distinctions – size, separation and orientation

Tightly Coupled

1:1 ratio of Tx to Rx coil

Tx and Rx coils:

Are generally closely matched in size and shape

Are generally in close proximity to each other

Generally utilize magnets or other mechanism to maintain precise alignment

Rx Coil

Tx Coil

2-4mm

Flexibly Coupled

Tx antennas are designed to create a CHARGING AREA or FIELD

Allows devices to charge effectively even when Tx & Rx is separated by 10’s mm

Doesn’t affect coins, pens, magnetic strip credit cards

No precise alignment required of Rx to Tx

Not just limited to desktop solutions

Tx Antenna

Rx Antennas

~10’s of mms


Freedom of Design – Desire a Universal Solution

Multiple device types

Multiple charging locations needed


Tightly Coupled Technology Not A Universal Solution! Multiple positions needed

Specific to each device

Must identify each spot

Alignment techniques


Flexible Coupling A Truly Universal Solution!

NOT specific to device type

No need to specify location

No alignment needed


Form Factor Flexibility, Continued Tightly Coupled Loosely Coupled

Tightly Coupled Systems Loosely Coupled Systems

1) Must have Tx & Rx coils of comparable size

and dedicated area for each device form factor

1) Can have a range of antennas for Tx and Rx

therefore supporting form factors as small as

Bluetooth headsets while still supporting

smartphones, netbooks, etc.

Each device requires a dedicated

transmitter location where the coil

size is reasonably matched in size

or a multi-coil Transmitter is

required

Each device can be placed

anywhere on the transmitter


Freedom of Placement

Tightly Coupled Systems Loosely Coupled Systems

1) Single device must be placed precisely on coil

and use magnets or comparable alignment

techniques or

2) Requires multiple Tx “stations” for each receiver

3) Coil array based systems permit some degree

of placement flexibility while adding complexity

and cost

1) Place single or multiple devices anywhere on

charging tray, in any orientation, with no

alignment techniques required

Tightly Coupled Loosely Coupled

Specific Charging Locations

Charging

Area


Technology Features of Flexibly Coupled Wireless Power


Managing a multitude of different loads

Efficient power delivery from a fraction of a Watt to tens of Watts on the same charging surface – at the same time!

Different antenna sizes and different coupling strengths must appropriately share the available power

http://www.google.com/imgres?imgurl=http://www.itechnews.net/wp-content/uploads/2007/02/Sony-DSC-W200-digital-camera.jpg&imgrefurl=http://www.itechnews.net/tag/sony-dsc-w200/&h=330&w=400&sz=48&tbnid=drLmeaFc3APslM:&tbnh=102&tbnw=124&prev=/images?q=dsc+camera+images&usg=__RyNfdqaMyBeRt77s1F3cyEVH27Q=&sa=X&ei=xANPTIj0FZO4sQPK36X6Bw&ved=0CCIQ9QEwAw


Maintaining uniformity of H-field across X-Y-Z axis

Charge time must not be significantly impacted by device location within the charging area, nor by its being lifted above the surface or on top of another object.


Managing unauthorized/unidentified loads

Prevent heating of metallic objects

Prevent charging of non-approved devices


Ensuring coexistence and interoperability with all other antennas

There are now up to 10 different antennas in a single Smartphone!

Multiple WWAN frequencies, WiFi, BT, GPS, FM, TV, NFC, and more coming…

International regulations (e.g., FCC, CISPR) need to be satisfied for world-wide adoption

The device has to maintain full functionality so that the user can continue operating it while charging

0

20

40

60

80

100

0.01 0.1 1 10

H d

Bu

A/m

Frequency (MHz)

CISPR 11 Radiated emissions limits: group 2/class B device vs induction Cooking

appliance for commercial use ISM device at 3m

6.7

8M

Hz

13

.56

MH

z 2

7.1

2M

Hz

Back View Continue operating

while charging

WWAN Prx

GPS

BT/WLAN

FM UMB

WWAN Drx


Induction heating comparison

100

1000

10000

100000

0 1 2 3 4 5 6 7 8

Ind

ucti

on

heati

ng

(m

W)

Frequency (MHz)

Relative induction heating vs. frequency Coil pairs optimized for each frequency, common operating point

Droid X FOM

Droid 3 FOM

iP4 FOM

Inflection caused by litz

wire applicability Phone#1

Phone#2

Phone#3


Understanding Wireless Power Regulations


Regulatory Protecting Communication Services

Regulations are needed to ensure successful operation of public, private and government communications services

Regulations allow multiple services and technologies to successfully coexist

Achieve Electromagnetic Compatibility (EMC)

http://upload.wikimedia.org/wikipedia/commons/5/57/Willans_Hill_Comms_Tower.jpg


Regulatory

Consumer electronic devices must comply with applicable regulations before they can be placed on the market More and more electronic devices are using RF

technology for communication

Many of these same devices are expected to be charged using wireless power

Product Regulatory Compliance


Regulatory

Safety

Requirements for exposure to non-ionizing radiation

International standards on electrical safety

Efficient Use of Spectrum

Radio Frequency Spectrum is allocated by regulators to licensed and unlicensed services for which there are requirements for efficient use of the spectrum

Harmful Interference

Requirements for limiting RF emissions across the radio frequency band with the most stringent limits established for protection of radio services

Electromagnetic Compatibility (EMC)

In addition to emissions requirements, there are regulatory requirements defined in markets such as Europe for products to demonstrate a level of immunity

Key Areas Defined by Regulation


Regulatory

Regulatory compliance can be demonstrated through standardized simulation and testing to regulatory limits

RF Exposure Assessment

Radiated and Conducted Emissions & Immunity

Demonstrating Compliance


Regulatory Requirements for Wireless Power


Regulatory

Designed to transfers watts of power for consumer products and kilowatts for Electric Vehicles (EV)

Currently there are two types of wireless power transfer referred to as “tightly coupled” and “loosely coupled” systems

Frequency of operation ranges 10’s kHz to MHz

EV wireless charging in the 20kHz to 200kHz range

Tightly coupled consumer wireless charging in the range 100-300kHz

Loosely coupled technology providers are proposing frequencies in the range 150kHz to 15MHz

For wireless power systems, people will typically be in the very near field of the power source

Fundamentals of Wireless Power


Regulatory

The fundamental operating frequency and the signal characteristics determine the regulatory categorization for wireless power systems

In the US wireless power can fall into the category of ISM* equipment under Part 18 and/or intentional radiators under Part 15 of the FCC rules

The applicable limits for radiated emissions are significantly different depending on this categorization

Selection of the operating frequency is critical when considering that wireless charging will inherently have a high level of magnetic and electric field emissions

Applicable Requirements

0

10

20

30

40

50

60

70

80

0.10 1.00 10.00

E-fi

eld

(dB

uV/m

)

Frequency (MHz)

Emission comparison with FCC limits

FCC Pt.15 limit

FCC Pt.18 limit

Limits @300m Limit @30m

Part 18 ISM limit

allows unrestricted

emissions at ISM*

frequency (6.78MHz

shown)

*ISM: Industrial Scientific

and Medical


Regulatory

RF Exposure Requirements for wireless power systems

People will typically be in the very near field of the transmitter. Thus “Reference Levels” (Electric and Magnetic fields) should not be applied to characterize exposure.

All wireless charging systems should be assessed in accordance with “Basic Restrictions” specified in ICNIRP* 1998/ICNIRP 2010 as well as FCC requirements.

Restrictions on exposure to time-varying electric, magnetic, and electromagnetic fields that are based directly on established health effects are termed “Basic Restrictions.”

Depending upon the frequency of the field, the physical quantities used to specify these restrictions are current density (J), specific energy absorption rate (SAR), and induced electric field (E).

* International Committee for Non Ionizing Radiation Protection. ICNIRP is the International recognized body that sets guidelines for protection against adverse health effects of non-ionizing radiation.

Applicable Requirements (Continued)


Qualcomm’s approach to Regulatory Compliance


Regulatory

The regulatory assessment of Qualcomm ideas and inventions is normally performed early in the research and development cycle to determine:

Applicable worldwide regulations

Technical requirements based on harmonized standards

Methodology for demonstrating compliance

Qualcomm has a dedicated team of Electromagnetic Compatibility (EMC) and Regulatory Engineering experts with experience in simulation, design, test and regulatory certification

Qualcomm New Technology Introduction


Wireless Power Transfer System

Qualcomm has studied & developed two wireless power transfer systems

468 kHz system & 6.78 MHz system

Both systems are based on loosely coupled technology

Radiated emissions tests and RF exposure assessment have been performed on the 468 kHz and 6.78 MHz prototypes with comparable form factors and load conditions

Applicable Limits for RF Exposure

468 kHz wireless charging pad 6.78 MHz wireless charging pad


468kHz, E=8.3

6.78MHz, E=73.02

0

10

20

30

40

50

60

70

80

0.10 1.00 10.00

E-fi

eld

(dB

uV

/m)

Frequency (MHz)

Emission comparison with FCC limits

FCC Pt.15 limit

FCC Pt.18 limit

RE of charging at 468kHz

RE of charging at 6.78MHz

Limits @300m Limit @30m

Unrestricted limit at ISM 6.78MHz

Regulatory Radiated emissions assessment per FCC Pt.15/18 US limits


Radiated emissions assessment per CISPR 11 International limits for ISM Equipment

468kHz, H=60.50

6.78MHz, H=54.07

0

10

20

30

40

50

60

70

0.10 1.00 10.00

H-f

ield

(dB

uA

/m)

Frequency (MHz)

Emission comparison with CISPR 11 limits

CISPR11 G2B limit@3m

CISPR 11 cooker limit@3m

RE of charging at 468kHz

RE of charging at 6.78MHz

Unrestricted limit at ISM 6.78MHz


Regulatory

Demonstration of Compliance

Qualcomm RF exposure assessment

Identify usage model(s)

Determine the worst case scenario in terms of possible maximum RF exposure

Perform RF exposure assessment under the worst case condition(s) via simulations

Conduct the code and modeling validation by measuring free space H and E and comparing them with the simulated H and E in free space

Applications

Table top tray

Automotive embedded

Furniture embedded

Usage Model(s) for Assessment of RF Exposure


RF Exposure Frequency Dependency

Depending on the frequency of operation used by the wireless power system only one of the basic restriction parameters may dictate compliance

The following chart highlights the frequency dependency for the “Basic Restrictions” of SAR and induced current density (J) For a given design and use case definition

The lower the frequency the more challenging it is to comply with induced current density (J)

The higher the frequency the more challenging it is to comply with SAR

Frequency

150kHz Reference 10MHz

Com

plia

nce C

halle

nge


Alliance for Wireless Power (A4WP) Overview


A4WP Membership*

*as of August 6, 2012


What is A4WP?

An industry association open to companies interested in advancing the field of wireless power by delivering a specification that enables spatial freedom

Combines the research and design capabilities of some of the world's leading electronics companies to promote specifications for wireless power technology, products and services

Visit a4wp.org to learn more



Purpose Enable a global wireless power ecosystem

Vision Be the primary venue supporting the evolution of wireless power technologies, products and services.

Mission

Global standardization

Certification and testing

Regulatory compliance and policy

Purpose, Vision, and Mission


A4WP Technical Program

Focus on technology not implementation

The standard will define:

• Frequency of operation

• Signaling protocol

• Minimum power delivery

requirements

• Modes of Operation

• Compliance testing procedures

• Coexistence

The standard will NOT define:

• Materials and vendors

• Load control mechanism

• Regulatory compliance

• Battery related requirements

• Receiver & transmitter

architecture


Alliance Structure, Function & Relationship to SDOs

Technical

Standards

Program

Testing, Certification and

Regulatory Program

Technical Marketing

and Communications

Program


Activities complement international SDOs

Make contributions to SDOs

Members can make contributions to SDOs


Alliance

Q2 CY 2012

Announced launch of Alliance

Initial collateral available

2H CY 2012

Launch global (B2B) marketing effort

Hold inaugural international Alliance event

Introduce initial baseline draft specification

Q4 CY 2012 – 1H CY 2013

Initial commercial products available

Work Plan Time Table


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information of Qualcomm Incorporated and all rights therein are expressly reserved. By accepting this

material the recipient agrees that this material and the information contained therein is to be held in

confidence and in trust and will not be used, copied, reproduced in whole or in part, nor its contents

revealed in any manner to others without the express written permission of Qualcomm Incorporated.

©2012 Qualcomm Incorporated. All rights reserved. Qualcomm and Snapdragon are registered

trademarks of Qualcomm Incorporated. All the trademarks or brands in this document are registered

by their respective owner.

QUALCOMM Incorporated, 5775 Morehouse Drive, San Diego, CA 92121-1714

Documents

Wireless Power Transfer Technology - PSMA...© 2012 QUALCOMM Incorporated. All rights reserved. 4 The Resonant Receiver Nikola TESLA 1901: Resonant Magnetic Induction 1902: Wireless