Small Temperature Sensor
Using mm-wave data and
power transfer
Presenter : ir. Hao Gao
Promotor : Prof. dr. ir Peter Baltus
dr. Marion Matters-Kammerer
dr. Dusan Milosevic
Outline
Sensors with Wireless Power Transfer
Mm-wave RF Wireless Power Receiver
Mm-wave RF Tag
60 GHz Ultra Low Power Radio
Conclusion
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Sensors with Wireless Power Transfer
 Medical and Health monitoring
 Structure Health monitoring
 Body Area Network
 Wireless Sensor Networks
 Smart building
Low data rate / low duty cycle / ultra-low power
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Sensor Evolution
Bottom
Buttom (With Solar Cell)
38mm
Top
Cons.:




8cm × 4cm
32cm2
Antenna Integration
Assembly Components
Battery Size
Hight Cost
(Y.H. Chee, Ali Niknejad, University of California at Berkeley, 2006)
Cons.:
3.8cm × 2.5cm
9.5cm2
 PCB Based
 Harvesting Method
not easy to integrate
(2.4 GHz)
(1.8 GHz)
( © BWRC,UCB, US, 2006)
3
25mm
© Hao Gao, MsM group, TU/e, h.gao@tue.nl
0.2cm × 0.1cm
0.02cm2
Solution:
 mm-Wave
 On-chip antenna
(60 GHz)
Why mm-Wave ?
Small wavelength enables:
Integrate antenna on-chip
Develop antenna arrays to
 Provide high antenna gain
 Provide highly directional pencil beams
Wide bandwidth available at 60 GHz enables
High data rate in the order of Gbits/s
Short transmission burst
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
mm-wave Problem
Rectifier performance conflicts with antenna size.
mm-Wave enables antenna on-chip.
Wide bandwidth available at 60 GHz.
 High data rate in the order of Gbits/s.
 Short transmission burst.
Rectifier performance at mm-Wave : Efficiency is low.
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Benchmarking
Frequency ( GHz )
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
60 GHz mm-wave Inductor-Peaked Rectifier
Problems:
 Low input voltage
 High threshold voltage
 Signal feed through
GND
RFIN
DCOUT
GND
GND
520 µm
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
350 µm
GND
Mm-wave Wireless Temperature Sensor
Base Station
with
Phase Array
Base
Station
Wireless Temperature Sensor Nodes
Vdd
Cstorage
RFin
8
RF-DC
Converter
Ultra Low
Power
End of Enable Transmitter
Burst
Temperature RFout
Monitor
Correlated
Sensor
© Hao Gao, MsM group, TU/e, h.gao@tue.nl
L6
M3
L7
M6
ULP
Tx
0.94mm
Three
Stage
Inductor
Peaked
Rectifier
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
M9
Rfout-
M14
L11
M8
M10 M11
M12
ULP Temperature Correlated Tx
λ/4 monopole antenna
Storage Capacitor
Array
1.16mm
L9
L8
L10
End of Burst Monitor
M13
R1
C5
M4
RF-DC Converter
Rfout+
L3
M7
M1
C2
L2
M5
L4
C3
C1
L1
C4
L5
Storage Capacitor Array
M2
RFIN
Mm-wave Wireless Temperature Sensor
0.75mm
71 GHz Tags : Block Diagram
On-Chip Antenna:
 Small size
Advantage:
 Monolithic, fully integration
 Small size, 2mm ×1mm
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Rectifier:
 Used as the supply voltage generator
End-of-Burst:
 Used as the input power monitor
71 GHz Tags : Measurement
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Future : 60GHz Radio-Triggered
Monolithic Wireless Sensor Node
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
60GHz data transfer: Ultra Low Power Radio
• Average power consumption optimization
Cause
High stand-by
power
High Power
consumption of
the mmW front-end
Circuitry
complexity
Modulation
complexity
System
architecture
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Minimize power floor
Remove the
high-power PLL
Relax Linearity
Eliminate the
square-law
Solutions!
Duty-cycled wakeup receiver (WuRx)
Injection-locked
oscillator (IJLO)
OOK based selfdemodulation
IJLO used in the
envelop detection
60GHz Injection-locked Oscillator
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Wireless Sensor System Evaluation
TX
Ant
Ant
Modulation
Power Gain TX Gain Rx
10 dBm 30 dBi
0 dBi
OOK
Pac.
BW
Tscav
Rx %
Len
2 GHz 10ms 20 bits
50
System parameters
Gain NF
IIP3
Pdc
(dB) (dB)
(dBm) (mW)
LNA 16.2
4.8
-18
5
Mixer -15
15
-22.4
Pout Sensitivity Pdc
frf
(GHz) (dBm) (dBm) (mW)
IJLO 61.6 -22.5
-60
3
60 GHz RF Front-End Parameters
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Conclusion
Battery-less sensor nodes enable many applications
Mm-wave wireless power transfer with integrated on
chip antenna is an elegant way for low cost solution
Key Circuit Blocks: High efficiency rectifier
System Level
: 60 GHz ultra low power radio
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© Hao Gao, MsM group, TU/e, h.gao@tue.nl
Acknowledgment
© Hao Gao, MsM group, TU/e, h.gao@tue.nl