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
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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
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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
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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MINIMUM-POWER RF ENERGY HARVESTING
Copyright Prof. Gregory D. Durgin 7
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:
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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.
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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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
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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.
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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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
-
+
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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Rectenna Array vs. SPCC
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Conversion Results
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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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
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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???
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RF Thermoelectric Generator
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
10
MINIMUM-POWER WIRELESS EXCHANGE
Copyright Prof. Gregory D. Durgin 19
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
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
11
Lets Start with the Link Budget
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Retrodirectivity
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
12
Example: Koo-Lu Modulator
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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
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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
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QTT Links @ Georgia Tech Campus
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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Link Parameters for QTT
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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
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
15
SUPPLEMENTAL SLIDES
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What About mm-Wave Backscatter?
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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How Much Data Can We Reflect?
Copyright Prof. Gregory D. Durgin 31
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
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
18
HIMR Estimate vs. Ground Truth
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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
Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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.
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Wireless Forever By Prof. Gregory D. Durgin
IEEE CRFID Distinguished Lecture Program -- 2014
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
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