dl presentation valpo - the propagation group€¦ · wireless forever by prof. gregory d. durgin...

Wireless Forever By Prof. Gregory D. Durgin

IEEE CRFID Distinguished Lecture Program -- 2014

1

the Future of RF Systems that Never Plug-in

Prof.GregoryD.Durgin,GeorgiaTechSchoolofECEDistinguishedLectureofIEEECRFID

WirelessoreverF

Big Questions for eXtremely Low-Powered (XLP) Wireless Systems Information Question What is the Minimum Power Required for Wireless Data Exchange? Energy Harvesting Question What is the Minimum Amount of RF Power Required to Drive Computation/Communications? Copyright Prof. Gregory D. Durgin 2



2

IEEE CRFID n Council within the IEEE n Conference Series

q IEEE RFID (April 2018 in Orlando, US) http://2018.ieee-rfid.org

q IEEE RFID-TA (Sep 2018 in Macau SER, China) http://2018.ieee-rfid-ta.org

n Educational outreach, distinguished lectures n IEEE Virtual Journal on RFID n IEEE Journal on RFID launched in 2017 n 21 member IEEE societies

Copyright Prof. Gregory D. Durgin 3

Trends in Electronics: Computation The energy-efficiency of computation doubles every 19 months, a consistent trend for over 70 years! The trend is independent of technological epoch (vacuum tubes, transistors, ICs, etc.) The trend will continue well beyond 2020.

1950 1960 1970 1980 1990 2000 2010 2020

1010

108

106

104

102

100

102

Year, Y

Jou

les/

Co

mp

uta

tio

na

l O

pe

ra

tio

n

Energy Eficiency of Computing over the Years

Vacu

um Tu

bes

Disc

rete

Tran

sisto

rs

Integ

rated

Circu

it Micr

opro

cess

ors

Multi

-Cor

e Micr

opro

cess

ors

*J.G. Koomey, IEEE Spectrum, March 2010



3

Trends in Electronics: UHF RFID This trend is driving the current buzz around the Internet of Things (IoT) and Internet of Everything (IoE). This energy efficiency doubles every 46 months. The 100m tag will likely occur around 2020. Or will it?...

1995 2000 2005 2010 2015 202010

10

10

Year, Y

UHF

RFID

Sens

itivi

ty (m

illiW

atts

)

Sensitivity of Passive UHF RFID Tags over Time

5m

9m7m 8m

12m

17m21m

26m

P. Nikitin, KVS Rao, S. Lam, UHF RFID Tag Characterization: Overview And State-of-the-Art. AMTA Conference, Seattle, Oct 2012.

What is Any of This Good For? n Personal Area Networks and Sensors n Environmental Sensors (Home, Agriculture,

Wildlife, etc.) n Low-Powered Exchanges for Cellular Network

q IoT devices that monitor/meter the environment q The Zombie Cell Phone field voice calls for several

days after your battery dies n Ultra-precise RF Wayfairing Points for Robotic

Systems




4

MINIMUM-POWER RF ENERGY HARVESTING


How to Rectify RF Power Lots of different circuits, but they all have the same limitation diodes. Diodes must turn-on before rectification, so they have a power overhead Curvature of a Schottky Diode:


C.R. Valenta, G.D. Durgin. Survey of Energy-harvester Conversion Efficiency in Far-field, Wireless Power Transfer Systems. IEEE Microwave Magazine. vol 14, no 4, June 2014. 10 pages.



5

Survey of RF Harvesting Efficiencies

30 20 10 0 10 20 30 40 50 60 700

20

40

60

80

100

Input Power (dBm)

Effic

ienc

y (%

)

900 MHz2.4 GHz5.8 GHzAbove 5.8 GHz


C.R. Valenta, G.D. Durgin. Survey of Energy-harvester Conversion Efficiency in Far-field, Wireless Power Transfer Systems. IEEE Microwave Magazine. vol 14, no 4, June 2014. 10 pages.

Power-Op)mizedWaveform(POW)

M.S. Trotter, J.D. Griffin, and G.D. Durgin. Power-Optimized Waveforms for Improving the Range and Reliability of RFID Systems. IEEE RFID 09 Conference, Orlando, FL. April 2009. 8 pages.



6

Test5.8GHzChargePumpwithPOWs

M.S. Trotter, Range Finding in Passive Wireless Sensor Networks Using Power-Optimized Waveform. Georgia Tech PhD Dissertation, Nov 2011.

Staggered-Pa8ernChargeCollector

-10dB

0dB5dB

2 x 2 SPCC

Single Element

Comparison ofArray Patterns

charge pump

ANT 1 ANT 2

ANT 3 ANT 4

charge pump

-

+



7

Rectenna Array vs. SPCC


Conversion Results




8

Pa8ernStrobing

step 1

Strobed Transmit Array Patterns

step 2 step 3 step 4

Passive5.8GHzTagProjectedRangex 0.16movefrom915MHzto5.8GHzx 0.71lossierelectronicsat5.8GHz(-3dB)x 4.016-elementbeamstrobing,powerbankingx 1.84-elementtagarrayforpowercollecNonx 2.0improvetagresonance,isolaNonx 2.4increasedbandwidth,POWgains= x 3.8netincreaseinrange26meterpassiverange->100meterpassiverange

Copyright Gregory D. Durgin 16



9

Future Innovation in RF Harvesting q Use of exotic

diodes: tunnel diodes, spin diodes, metal-insulator-metal (MIM) diodes

q RF Thermoelectric Generation (convert RF-to-heat-to-DC at nanoscale)

q Turn-on levels of -40 dBm or beyond???


RF Thermoelectric Generator




10

MINIMUM-POWER WIRELESS EXCHANGE


How UHF RFID Systems Work n Harvest an incident RF Wave n Increases range without power consumption n Power and communications channel both present

Copyright Prof. Gregory D. Durgin20

RF Tag

RF Reader

1

8

23

4

6

75

Generate

Locate

RadiatePropagate

Harvest

Scatter

Receive

Sense



11

Lets Start with the Link Budget


Retrodirectivity




12

Example: Koo-Lu Modulator


Quantum Tunneling Tag (QTT) Use RF negative-resistance devices (like tunnel diodes) as reflection amps Bank energy and bias the circuitry so conservation of energy still holds Eliminates the need for RF signal-generator circuitry, which dominates power consumption at low transmit power levels



13

Demonstration of Actual Data n 5.8 GHz carrier n Low-powered

transmitter (-20 dBm) n TR separation distance

of 7 m n Transmit and Receive

antenna gains of 6 dBi n 250 kbits/sec transition n About 35 dB of

reflection amplifier gain


QTT Links @ Georgia Tech Campus




14

Link Parameters for QTT


Summary Low-Powered Wireless Information: n Today, we can build devices that communicate at

kilometer distances with microWatt consumption. n Need for more exploration, physical layer

experimentation, application development

RF Energy-Harvesting: n We are less than 5 years away from 100m+ purely

passive wireless devices n Still very far away from the theoretical limits




15

SUPPLEMENTAL SLIDES


What About mm-Wave Backscatter?




16

How Much Data Can We Reflect?


Helmet Shock Sensor System: 5.8 GHz backscatter tags equipped with low-powered, accelerometer/gyrometer MEMs sensors that track real-time head trauma events on a sports field Communications: provides more than 200 packets of 6-axis motion data per second at 30m range Power: oin cell battery provides potentially months of operation

https://www.youtube.com/watch?v=_DGn6HPooRk



17

Wireless Motion Capture Hybrid Microwave Inertial Reflectometry (HIMR) uses phase measurements + inertial data from sensor link to pinpoint a backscatter tag Tests on a 5.8 GHz tag on a high-speed robotic positioning arm produce position estimates with mean and standard deviation errors of less than 2mm

Demonstration n 5.8 GHz backscatter

setup n Tag sends 200 packets

per second of 3-axis accelerometer data

n Motion track capable of moving tag up to speeds of 1.6 m/s




18

HIMR Estimate vs. Ground Truth


Detection of Card Skimming Devices

Electromagnetic Integrity and Security Assay (ELISA) System

M.Morys, M. Akbar, G.D. Durgin, Malevolent Object Detection Using Microwave RFID Tags, IEEE RFID 2013



19

How ELISA Works Sensitized microwave antenna (upper right) with load-modulated IQ signal returned to a nearby reader (lower right). Constellation remains constant excepting temporary changes during human equipment usage. Any dielectric components or small wires (e.g. a small foreign electronic device) placed nearby will distort the constellation.

M.Morys, M. Akbar, G.D. Durgin, Malevolent Object Detection Using Microwave RFID Tags, IEEE RFID 2013

Measured Performance As a short, thin wire is moved away from the loop antenna, the backscatter amplitude and phase changes, as measured by Normalized Symbol Distance. Highly reliable measurement, nearly impossible to spoof. Other tamper detection applications possible.




20

Hope Diamond Security System System: ELISA-based security system that works through ceilings, walls Communications: backscatters 5.8 GHz FSK temperature, humidity data with custom protocol Power: Coin cell and passive tags designed and built


dl presentation valpo - the propagation group€¦ · wireless forever by prof. gregory d. durgin...

Documents