John L. Volakis Th Ohi St t U i itThe Ohio State University · Th Ohi St t U i itThe Ohio State...
Transcript of John L. Volakis Th Ohi St t U i itThe Ohio State University · Th Ohi St t U i itThe Ohio State...
Antennas & RF Sensors: Changing the Way We Live(from mobile telephony to electronic textiles and RFIDs)
John L. VolakisTh Ohi St t U i itThe Ohio State University
Coupled
UncoupledUncoupled
Coupled
UncoupledUncoupled
L1C1
L3 LMC3
CM
(V1 I1) (V3 I3)
Coupled
UncoupledUncoupled
Coupled
UncoupledUncoupled
L1C1
L3 LMC3
CM
(V1 I1) (V3 I3)
0
L2C2
0
L3 LM
0
C3
0
CMLM(V2 I2) (V4 I4)
Inductive coupling
Capacitive coupling
0
L2C2
0
L3 LM
0
C3
0
CMLM(V2 I2) (V4 I4)
Inductive coupling
Capacitive coupling
1
Why so much interest in Antennas and RF Devices?
Miniaturization need for sensors and mobile systems
Compact communication systems with higher data rates
More than 50% of a system-on-a-chipconsists of passive RF devices
RF & Microwave Magazine 2006
Conformal antennas for commercial and military applications Multifunctionality to
decrease complexity & cost
IEEE Spectrum
2
Enabling RF Technology for Daily Life Convenience60 trillion wireless sensor till 2010-12, viz. 10,000 for every person in the world
Wearable Antennas and Sensors are being developed with conductive textiles to:Monitor Health (blood pressure, fluid levels etc.)
P iti D t ti
Engineered Substrates for:Miniaturization, Multifunctionality & Greater Bandwidth
Position DetectionDecrease Weight and Complexity of Existing
Wireless Devices
System design to communicate various h h
Challenges:• Convenient way of Substrate Patterning & Printing (Metamaterials) is not yet realizable• Integration of RF circuits is not realistic in existingRF components to each other • Integration of RF circuits is not realistic in existing technology (only in low constant materials)
From syringe
Coated matrix template
Repeat printing process on top of solid sheetsHealth Monitoring
Challenges:
Incorporate various RF technology (Bluetooth, GPS, Health Monitoring) into existing devices- Small RF devicesChallenges:
- Tissue Characterization- Understand effect of RF signals on human body- EM Compatibility with biological structure
Small RF devices- High gain antennas for far distance communication (GPS)
5
Sensor Systems/System on a Chip Overview
P D h i l dPurpose: Detect chemical agents and vapor mixed in the air at low levels.
Deployment: Sensor can be placed in theDeployment: Sensor can be placed in the air-ducts of air conditioning systems.
Size: 2-3cm per side. Fairly flat
6
RFID Everywhere
Automobile industryA i ti• Electronic Toll Collection• Access Control• Animal Tracking
Automobile industryAviation
• Animal Tracking• Inventory Control• Tracking Runners in
Races!2000 RFID points • Anti-Theft
PharmaceuticalsID CardsID Cards
7
Ohio State’s RFID Bug Tracking Radar Goes Up to 190ft (63m)
RF Front End1. 5.9 GHz CW
signal transmitted
2. Signal intercepted by tag (up to 200’ away), harmonic re-radiated
Xmit: 5.9 GHz
3. 11.8 GHz signal received, down-converted
~200’Transmit/Mixing Circuits
Proposed Array:
Rec: 11.8 GHz
4. IF Signal: Indicates presence of tag
Rec. Circuit
Proposed Array:-Xmit ~ 14” x 7”-Rec ~ 7” x 3.5”-Gain ~ 20 dBi
Meandered Loop Tag•Tag measures 9.5 mm x 9.5 mmmm.•9.5 mm ~ 0.19λat 5.91 GHz (Xmit freq.)
8
RFID Reader System Remains a Challenge- RFID readers and tagging promise to revolutionize retail, gg g p
supermarket and warehouse shelving systems, including purchasing process and habits
Fading is a major issue. Spatial and
Re
R t il Sh lTwo distributed antennas mounted vertically behind t d d t il h lf
Fading is a major issue. Spatial and polarization diversity of the distributed antennas overcome fading in both static and dynamic environments.
eader
Retail Shelves
RFID Portalstandard retail shelf
Various metallic and non-metallic RFID tagged items arranged on shelves
Elongatedte
nna
Loaded pallet
d RFID
coveragribut
ed A
nt
ge areaDis
tr
Reader
Two distributed reader antennas on each sidewall 10
Container Product Tracking SystemsFor a typical container 10’x10’x40’ with tightly stacked cartons, we need to use 8 distributed antennas to illuminate entire container. Folded tags are also needed to
Container Side View
distributed antennas to illuminate entire container. Folded tags are also needed to get good performance.
10’
40’40
Folded tag deployment Antenna Deployment (Top View)
6’4’6’4’6’4’6’2’
Folded tag deployment
2’6”
We place 2 antennas to cover a 10’x10’x10’ volume of the container. For the entire container, we need 8 distributed antennas
11
Real Time THz Imaging of Excised TissueTARGET APPLICATION:Breast Cancer Detection 1 in 8 women will have breast cancer in their lifetime
Digital Processing
THz Imaging System Overview
Ti S lbreast cancer in their lifetime 96% curable if caught early-----------------American Cancer Society, Inc,
Tissue Sample
Surveillance Research
Current Breast Cancer
THz Detector Array
Object LensTHz Image
Working PrinciplesDetection Issues:X-rays not of sufficient resolution/information; also not desirable due to inherent
Direct detection of THz radiation using diodes having superior noise performance • Build compact detector layouts suitable for 2D arrays not desirable due to inherent
ionization.80% of biopsies unnecessary
E i d ti i i i
• Explore/optimize array topologies for maximum number of detectors (equivalently pixels), power transfer and detection performance• Investigate suitable imaging algorithms to be
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Excised tissue imaging is desirable during operation but very slow
Investigate suitable imaging algorithms to be incorporated into the imager signal back-end• Frequencies: 100GHz, 500GHz, 800GHz
Body Worn Antenna Coverage with Diversity Module
20dB 20dB –– 30dB fluctuation reduces to 3dB 30dB fluctuation reduces to 3dB –– 4dB 4dB
dBm
]Antenna 3Antenna 4
ved
pow
er [
Antenna 1
mal
ized
rece
iv
Ant1- front torso
Ant2- back torso
Nor
m Ant3- R. shoulder
Ant4- L. shoulder
Module output
iWAT2009 13Azimuth angle [deg]
Rotator
Miniature Antennas and Arrays for THz Imaging
Multiband Antennas: Detection at multiple frequenciesSmaller size antennas to avoid aberrations
1um 3um94um
1um 3um94um
Antennas with controlled radiation patterns More antenna elements (pixels)
580um580um
Metamaterial
50um111u
m
18um
11.4
1.80.6
3um
1.8um
75um
3um1.8 50um11
1um
18um
11.4
1.80.6
3um
1.8um
75um
3um1.8
-15
-10
-5
0dB(S11)
ParasiticallyLoaded
280um
420um
280um
420um
Asymmetrically Fed
Much smaller
Metamaterial miniature antennas for small pixel size
300 400 500 600 700 800 900 1000-30
-25
-20
Frequency(GHz)
Dual band folded slot antenna for 500 &
500GHz 800GHz
Loaded Fed metamatetial-based multiple antennas for pattern control
Dual band folded slot antenna for 500 & 800GHz breast cancer detection
Imaging arrays with multiple detector (antenna
Photonic Crystals & Metamaterials
array) layouts for pattern diversity
Metamaterials High gain apertures and miniature arrays Negative refraction for sub-wavelength focusing
14
wavelength focusing
Wireless Landscape
1000 ?
50002005 Wireless Landscape1000 ??
50002005 Wireless Landscape
500
s)
?
100
Continually Evolving
802.15.3aUW B
500
s)
??
100
Continually Evolving
802.15.3aUW B
Future wireless systems will focus on high
10ate
(Mbp
s
50
802.16802 15 3 802.11a/g Fixed
UW B
802.11n
10ate
(Mbp
s
50
802.16802 15 3 802.11a/g Fixed
UW B
802.11n
y gdata rates to deliver content as rich as that in current wired systems
issi
on ra
UMTS / HSDPA /
802.11bWiFi1
5 Canopy
WiMax802.15.3
Bluetooth
Mobile/Nomadic802.16e / 20
issi
on ra
UMTS / HSDPA /
802.11bWiFi1
5 Canopy
WiMax802.15.3
Bluetooth
Mobile/Nomadic802.16e / 20
0.1
0.5
Tran
sm
BlackberryGSM/TDMA
GPRS/EDGE
UMTS / HSDPA / 1xEVDO
ZigBee802.15.4
Bluetooth802.15.1
0.1
0.5
Tran
sm
BlackberryGSM/TDMA
GPRS/EDGE
UMTS / HSDPA / 1xEVDO
ZigBee802.15.4
Bluetooth802.15.1
Range (meters)10 100 1000 10 000 100 000
y
1Range (meters)
10 100 1000 10 000 100 000
y
1
15
Antenna/RF Sensor Challenges and Solution Trends
Applications Solution Trendspp• Multifunctional Radios• Software Radios/Radars
Solution Trends• Materials
Magnetics films/Multiferroics• Short Range Giga-bit Comm.
& Data transferUWB i i f MH t
g• Composites (polymers,
mixed material systems, multi layered emulated• UWB imaging from MHz to
THz.• Sensing and monitoring
multi-layered, emulated anisotropy)
• High speed interconnectsg g• Identification• Body worn systems
g p• Structurally reinforced smart
skins (carbon nanotubes, i )• THz imaging ceramics )
ferroelectricferromagnetic
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Military ChallengesMilitary Challenges• OSD report (Appendix C, p.9): Over the long term
2012-2030, JTRS, including wideband networking2012 2030, JTRS, including wideband networking waveforms (WNM), will provide a fully integrated information system network to include active and passive information operation management across the joint and combined environment. The system will also include a self-establishing and self healing smartalso include a self establishing and self healing smart network, which will automatically manage the RFdomain.
• WNM will operate from 225-400MHz, and is intended to enhance or replace currentintended to enhance or replace current systems such as the Single Channel Ground and Airborne Radio System (SINGARS, 30-88MHz), EPLRS (450-470 MHz), and Link 16. Gi th t t i l l th i• Given that typical wavelength size antennas are /2 long/wide (5m or ~15ft at 30MHz), they must not only be structurally embedded but also muchstructurally embedded, but also much smaller (miniature) than currently available to accommodate future real estate.
17
Future Smaller Aircraft Needs• Challenges
S ll i UAV d RF ti ( i ti i i– Small size UAVs and RF congestion (communications, imaging and information gathering on small platforms)− high speed communications: from 15kb/sec to
5Mbits/sec, 3000 times higher speedsg p− 30-5000MHz ultrawide band antennas (with wavelength
5m or 15ft) must be reduced in size by a factor of ~5-10 and integrated on small platforms with gains for high data ratesdata rates
− High gain/narrow-band antennas for radar, imaging, guidance, satellite communication, and other specific applications
t Gl b l H k S tC t i till---current Global Hawk SatCom antenna is still a (rotating) reflectors,
---future apertures must be conformal and suitable even for small UAVs
– Entire UAV surface may serve as a RF (smart) skin, implying structural integrity of the RF functional layers
– Volumetric exploitation to address low frequency performance is a major design and computational challenge.
– Multiphysics tools must address concurrent structural/fatigue and RF performance requirement; need for multiphysics design optimization tools
– UAV sections may be removable and re-bonded for multiple missions 18
Traditional antennas will be a thing of the past!!
Artificial or RealArtificial or RealMaterials?
19
Antenna Miniaturization ApproachesAntenna Miniaturization Approaches
Increase Antenna Electrical Size
Slow down currents flowing on antenna, using inductive and capacitive loading :
L1 effΖ μ2 2 eff∇ E+ω μ ε Ε = 0 Ζ =
Load antenna near fields with material εr,μr :
effυ = ,Ζ =g CL C effeff eff∇ E+ω μ ε Ε = 0,Ζ =weff eff εeff
Increase Radiation, Bandwidth and Efficiency Compared to un-miniaturized Antennas
,
Artificial Transmission Line (ATL) Material Loading20
Matching Networks Significantly Improves Low Frequency Performance
0
10
Final Operating Frequency 178 MH (60% t t l
-20
-105 segments
Possible matching Circuit from Optimization A d 80% Mi i i ti
15”MHz (60% total minimization)
-40
-30 Non OptimizedCase A(Best)Case A With Matching
2
0
2
from Optimization Around 80% Minimization
0.2 0.4 0.6 0.8 140
-6
-4
-2
-12
-10
-8
Non OptimizedCase A(Best)
Final Operating Frequency can go down to 175MHz
GAcase13.02d.FlarDipoleRun.2.case.1.iter.1.gen.8.run.44
0.15 0.2 0.25 0.3-14
Case A With Matching
21
Array planeMunk’s Current Sheet Antenna
superstrate
Z1+=jZotan(kdo)d
Array Geometry
do
Ground Plane
Impedance looking into theground plane is inductive
Capacitive load(realized via the i t di it linterdigitalcapacitor fingers) to cancelinductive ground gplane effect
Interdigital capacitive loads; As the frequency increasesInterdigital capacitive loads; As the frequency increases, capacitance increases to cancel inductive load caused by the ground plane. This results in nearly purely resistive impedance, giving rise to the large bandwidth
22
2-18GHz PerformanceF B d 2 18 GH
30308x8 Active Array Broadside Gain 30308x8 Active Array Broadside Gain
Frequency Band: 2-18 GHzPolarization: Dual LinearOverall Size: 22”x22”Total Elements: 2664 Dual PolActive Elements: 64 Dual Pol
20
2525
20
i)
20
2525
20
i)
Active Elements: 64 Dual PolAperture Thickness: 0.8”
5
10
15
Gai
n (d
Bi)15
10
5ain
(dB
i
5
10
15
Gai
n (d
Bi)15
10
5ain
(dB
i
-5
0
5G
CSA11 Measured w/ coupling plates
Theoretical 8X8 Unit Cell Gain
5
0
-5
Ga
-5
0
5G
CSA11 Measured w/ coupling plates
Theoretical 8X8 Unit Cell Gain
5
0
-5
Ga
0 4 W/element-10
2 4 6 8 10 12 14 16 18Frequency (GHz)2 4 6 8 10 12 14 16 18
Frequency (GHz)
-10-102 4 6 8 10 12 14 16 18
Frequency (GHz)2 4 6 8 10 12 14 16 18 Frequency (GHz)
-100.4 W/element
23
Frequency (GHz)Frequency (GHz)23
Enabling Miniaturization of Broadband Apertures
Just another way of capacitive coupling
Munk’s/Harris Corp. Current Sheet Aperture (CSA)Munk s/Harris Corp. Current Sheet Aperture (CSA)
Matching with Negative Elements
0 F 77pH
-1.45pF -256nH• Antenna final size: λ/12xλ/18• 3.5:1 bandwidth• No use of any material loading
3
Realized Gain before…
enna-128pF -18.5µH
0pF -77pH
Input
-3
0
3
240 to 1050MHz (4 5:1)
Ant
ep
Values from optimization
200 300 400 500 600 700 800 900 1000 1100
(4.5:1)
Keep (almost) th
Decrease the t i b
-1000
0500
Reactance
0
3
the same bandwidth
antenna size by 3
50 200 400 600 800 1000 1200
-2000
75150
2550 75 100 125 150 175 200 225 250 275 300
-382 to 275MHz
(3.5:1)
50 100 150 200 250 300
-150-75
075
After…25
…… benefits for magnetic materials are there
0
5
1 0
-1 5
-1 0
-5
tal G
ain
(dB
)
M3 ferrite
-2 5
-2 0
-1 5
Rea
lized
Tot
fre e s ta n d in go ve r in fin ite g ro u n d p la n e , h 1 = 3 ''
M3-ferrite cylindrical cavity
0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0-4 0
-3 5
-3 0
in fin ite g ro u n d p la n e , w 1 = 3 '', w 2 = 4 '', h 1 = 3 ''in fin ite g ro u n d p la n e , w 1 = 1 '', w 2 = 1 '', h 1 = 3 ''in fin ite g ro u n d p la n e , w 1 = 1 '', w 2 = 1 '', h 1 = 4 ''in fin ite g ro u n d p la n e , w 1 = 1 '', w 2 = 1 '', h 1 = 5 ''
0 5’’0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0F re q u e n c y (M H z )
0.5
26
Limitation of current magnetic materials & losses
•Existing materials turn out to be “very” lossy at UHF frequencies, for
Material losses cause gain reduction
freeantenna applications
•Losses cancel out the miniaturization obtained by the
free space
miniaturization obtained by the ferrites
•Material losses need to be lower than 0 005 in order for the ferrite
tanδ must be <0.005
Material specifications
than 0.005 in order for the ferrite loading to be beneficial
Gain reduction appears as shifting up in frequency
p
•εr=μr(impedance matching)
•losses<0.005(<500 MHz)
ε μ values : 8 14
f : -15dB frequency, losses
fo : -15dB frequency, lossless • εr, μr values : 8 - 14
27
Antenna Miniaturization Techniques
1 Slow down current flow by1. Slow down current flow by material loading• Homogeneous material (broadband)• Inhomogeneous, anisotropic material
k
k
cvg
g p(narrowband)
• Magnetic Material (narrowband, bias required)
2. Control current phase velocity by
kcvp
2. Control current phase velocity by controlling L and C of equivalent transmission line model
k
L L
C CC
L L
C CC
v 1effL
Z
28
effeffp CL
veff
c CZ
Temex Microwave Ferrite Materials Catalog, http://www.temex.net/temex/catalog/TEM01.pdf
28
Eploiting 3D Anisotropy…•3D anisotropy modifies the k- diagram of the material medium
• Concurrent slow wave velocity & impedance matching lead to small RF devices with high sensitivity and high gain vs bandwidth.
k
cvg
kv
Material DNA• RBE modeFrozen Modes• DBE mode
k k
cvp
Flat sections, imply slow velocity
• DBE mode• MPC modek
• math concepts to RF designs and actual antenna realizationsFlat sections, imply slow velocity
1060
90
120
0
5
30
210
240 300
150
330
180 0
DDMMeasurementHFSS
x
240
270
300
Concept
y
12dB vs. 1.7dB Simulations FabricationTesting
100% apertureefficiency 29
Realization and Demonstration of Degenerate BandEdge (DBE) Mode in a Periodic Assembly
3456
E|m
ax
x
zy
PEC5-folds amplification
12
15
3210012
Layer #
|
Field profile for reception
yiE
φ=52.5o
3
6
9|H
|/|H in
c|
Field profile for reception3 Layers=0.96cm
0.28 λ05 7.5 10 12.5 15 17.5 20
0
3
Frequency(GHz)
New FEM Domain Decomposition Tools required (for 16M DOFs):
1 4GB 30GBFeeding Schemes: Slot on ground plane, dipole in B1 layers
Easier to implement, external feed/matching
---1.4GB vs 30GB---CPU: 2.5 hrs
5
1060
90120
Simulated (DDM)Measured (OSU-ESL)Measured (NASA)
030150
180 0
Directivity:10.15dB, over 100% aperture efficiency
210
240270
300
330
30
Performance of the Degenerate BandEdge -DRA Antenna
104
th
Optimal Curve
Leaky Wave DRA 102
n x
Ban
dwid
t yRegionRegion
2
100
Gai
n
0 5 10 15 20 25 3010-2
kaλo/8.12 λo/8.12
λo/1845o
DBE Antenna Prototype
Hybrid DBE Mode DRA Antenna 31
Printed Lines with Lumped Elements allow for much Greater Control of the Dispersion Diagram and Propagation Properties
Forbidden Frequency BandP
Propagation Band Structure• Flatter higher Q/gain (slow velocity)• Inflection point high Q, greater bandwidth (slow velocity, excellent
t hi t di l t i i t f
quen
cy
q y
SIP k= points
RB
E
SIP matching at dielectric interface – zero acceleration)• kd = 0 lower frequency resonance (small size)
kd t d d DBE/
Freq
• kd = standard DBE/resonance
Realization: 4-port circuit model
0 2
Propagation Constant (K)
Port 1
Port 3
Port 2
Port 4C
LC
CC
Microstrip TRLs
Patent Pending
Very low resonances achievable Dashed: Ordinary materials
p g ( )L
CC
Series Chip Capacitors Parallel Chip Inductors
Engineered Crystals to Control k- diagramInterdigital Capacitors
Shunt Inductors
33
Equivalent Circuit Realization of the DBE Antenna (TL pair with Controlled Coupling, Patent Disclosure)
Bloch analysis (with transfer –ABCD matrices)
L1 = L2 = L3 = 1nH,
Capacitively Loaded TLs: Coupling Capacitor tunes DBECoupled
UncoupledUncoupled
Hz)
L1 L2 L3 1nH,C1 = 10pF, C2 = C3 = 1pF
L1C1
0
L3 LMC3
0
CMLM
(V1 I1)
(V I )
(V3 I3)
(V I )
Uncoupled Phase shift Coupled Coupling capacitor and requ
ency
(GH
CM = 0.5pF
CM = 1.5pF
CM = 2 5pF
L2C2
0
L3 LMC3
0
(V2 I2) (V4 I4)
Inductive coupling
Capacitive coupling
Uncoupled – Phase shift difference due to separate LC loading emulates anisotropic ε tensor
Coupled – Coupling capacitor and inductors realize propagation in rotated anisotropic ε tensor
K – Bloch Wave Number
F CM = 2.5pF (DBE)
DBE design Guidelines: K Bloch Wave Number
ncy
(GH
z)
CM = 2.5pF (DBE)
DBE design Guidelines: Unit cells with capacitively loaded TLs (C > L) are tuned to DBE via coupling capacitor (CM). Inductively loaded (thin) TLs (L < C) are tuned to DBE through inductive coupling (LM). Pros & Cons of CM tuning: CM can be easily realized with chip capacitors.
K – Bloch Wave Number
Freq
uenHowever (C > L) TLs are very thick on low contrast substrates.
Pros & Cons of LM tuning: Thin TLs have L > C. But, realizing LM on printed circuits is challenging (needs transformers) Combination of thick and thin TLs for miniaturization & CM tuning
34
DBE Antenna Design Using Lumped Circuit Model
Choose Circuit Layout Suitable for Circular Cascading 1
Coupling Coupling capacitor
2 Microstrip and Lumped Element Realization via Full Wave Simulators
C1 C2
CM
C2 C1
p g Coupling capacitor
Loading
L1 L2 L2 L1
CL
Capacitively Loaded Lines
Substrate: Duroid, ε=2.2 tanδ = 0.00092 inch x 2inch x 0.125inch(5.08 cm x 5.08 x 0.3175cm) Same with Ground Plane
capacitor = 1pf
Loaded Lines
GH
z) CM = 0 pF
CM 0 5 F
Coupling Freq
uenc
y ( CM = 0.5pF
CM = 0.65pF (DBE)
K – Bloch Wave Number35
Optimal Antenna Size Using DBE ModePrinted on High r Substrate
0.85 inch (2.16 cm)
50 ΩCoaxial Cable
H = 0.5 inch (1.27 cm)Measured 3~3.5% Bandwidth
Coaxial Cable (Capacitively Coupled)
0.88 inch (2.24 cm)
Substrate: Alumina, ε=9.6 tanδ = 0.00032 inch x 2inch ~ (5.08 cm x 5.08 cm) (Same with Ground Plane)
4.25 dB Gain at 1.445 GHz CoorsTek AD-995 substrate: Alumina ε = 9.7 2inch x 2inch x 50mil
The antenna has dimensions of ~λ0/9.6 x λ0/9.3 x λ0/16 at 1.445 GHz
Realization of these elements on devices with self-scanning capabilitiesshould provide for satellite to
This design seems to be the smallestantenna anywhere for the given gain and bandwidth
should provide for satellite to handheld communication
36
DBE Antenna with Lumped Capacitor Loading
Electric field at DBE Resonance
Antenna Layout
20-5
0
45-45
Measured Gain
1inch = 2.54cm Capacitively coupled coax Measured
S
-10-15dB
90
135
-90
135
20 % shift
B(S
11)
ency
(GH
z) CM = 0 pF
CM = 0.5pF
CM = 0.65pF ency
(GH
z) CM = 0 pF
CM = 0.5pF
CM = 0.65pF -6
-4
-2
0
2
(dB
)
S11135-135
180
20 % shift 0.4%BW2dB Realized GainExplore 20%shift in
dB
K – Bloch Wave Number
Freq
ue
p(DBE)
K – Bloch Wave Number
Freq
ue
p(DBE)
2 2.2 2.4 2.6 2.8 3-16
-14
-12
-10
-8
Frequency (GHz)S
11
CM=0pF
CM=0.5pF
6.3dB Gain (w/o capacitors)
1.8dB Gain
presonance frequency for reconfiguration (time varying DBE antenna)
CM = 0pF (0.9% BW)
CM = 0.5pF (0.4%BW)
CM = 0.65pF (DBE) (0.25% BW)
Thicker substrate increases the6.9dB Broadside Directivity
Frequency (GHz)
Radiation efficiency is 35% due to the lossy lumped elements
37
Thicker substrate increases the bandwidth: 125mil = 0.25% BW vs. 275mil 1.5%BW
Varactor Loaded Tunable Antennas
Antenna Design Experimental verificationVaractors (cm) Skyworks smv-1405 varactors:
2.67pF (0V bias) - 0.63pF (30V bias)
Antenna Design Experimental verification
Control signal (18nH)
Control ground (18nH)RF inputAntenna Footprint (on εr=2.2 substrate): 2" × 2" × 0.25"
λ /4 0 × λ /4 0 × λ /31 @ 1 490GHz (cm = 0 0pF) Tunable from 1 12GHz to 1 31GHzλ0/4.0 × λ0/4.0 × λ0/31 @ 1.490GHz (cm = 0.0pF) λ0/4.3 × λ0/4.3 × λ0/35 @ 1.366GHz (cm = 0.5pF)λ0/4.8 × λ0/4.8 × λ0/39 @ 1.218GHz (cm = 1.0pF)λ0/5.4 × λ0/5.4 × λ0/43 @ 1.087GHz (cm = 1.5pF)
Tunable from 1.12GHz to 1.31GHz
Improving antenna performance: Improving antenna performance: 1) Varactors tunable from 0pF to 2pF (1GHz – 1.5GHz)2) Low loss varactors3) Smaller capacitances for higher frequencies
Higher order K-ω Diagram Using Multiple Transmission Lines
Coupled
UncoupledUncoupled
(V I ) (V I )
Coupled
UncoupledUncoupled
Coupled
UncoupledUncoupled
(V I ) (V I )
1I
1V
2I
4I
4V
I
11L11C 21L
21CM1C
M3C
1I
1V
2I
4I
4V
I
11L11C 21L
21CM1C
M3C
Realization of Symmetric SIP:SIP at ~2 9GHz
L 1C 1
0
L 2C 2
0
L 3 L M
L 3 L M
C 3
0
C 3
0
C MLM
(V1 I1)
(V2 I2)
(V3 I3)
(V4 I4)
Inductive coupling
Capacitive coupling
L 1C 1
0
L 2C 2
0
L 3 L M
L 3 L M
C 3
0
C 3
0
C MLM
(V1 I1)
(V2 I2)
(V3 I3)
(V4 I4)
Inductive coupling
Capacitive coupling
2V2I
3V3I
5I
5V
6I
6V
12L12C
13L13C
22L22C
23L23C
M2C
M3C
2V2I
3V3I
5I
5V
6I
6V
12L12C
13L13C
22L22C
23L23C
M2C
M3C
550mil
SIP at 2.9GHz
ency
(GH
z)
3 Uncoupled lines 3 Uncoupled lines 3 Coupling Capacitors
Coupled lines
3 Uncoupled lines 3 Uncoupled lines 3 Coupling Capacitors
Coupled lines
Effect of Tree-way Coupling (CM3 nonzero) on K-ω Diagram:• Lower order K ω branch can display a 6th order behavior
Coupling Capacitors
Freq
u
K- Bloch Wavenumber
Hz)
Higher order K-ω curve
Hz)
Higher order K-ω curve
Higher order K-ωCurve
• Lower order K-ω branch can display a 6th order behavior.• Symmetric stationary inflection points (similar to SIP in MPCs)
z)
z)
•Symmetric Stationary Inflection Points in the
p
Freq
uenc
y (G
H
Freq
uenc
y (G
H Curve
Freq
uenc
y (G
Hz
Freq
uenc
y (G
Hz Inflection Points in the
Propagation Spectrum
•Achieved without resorting
39
K – Bloch Wavenumber
K – Bloch Wavenumber
K – Bloch Wavenumber
K – Bloch WavenumberL11 = L12 = L13 = L21 = L22 = L23 = 1nH, C11 = 10pF, C12 = 5pF, C13 = 1pF, C21 = C22 = C23 = 1pF, CM1 = 2pF, CM2 = 2pF, CM3 = 2.6pF
to lossy ferromagnetic layers!
Magnetic Substrates and Realization of Magnetic Photonic Crystal Modes
N21
Z01
Z02
Z03
Z04
……
……
……
excitation
N = 64excitationDBE vs. MPC Antenna Performance
40
Tuning Non-Reciprocal K-Diagrams.
• Ferrite substrate only under the coupled sections.
H0
dielectric ferrite Provides Several Advantages:• Ferrite losses kept to a minimum (only
small ferrite substrate sections)s a e i e subs a e sec io s)• High epsilon (r ≈ 15) ferrite (r > 1)
adds to miniaturization• Radiation mechanism similar to patch
H0
ferritefringingfields
• Radiation mechanism similar to patch antennas (fringing fields on dielectric substrate)
• Ferrite inclusion allows for design• Ferrite inclusion allows for design flexibility for matching and tunability
• Standard bandwidth increase techniques can be
41
qincorporated
Specific Design with Magnetic Inserts
2”
r = 2.2, tan = 0.0009
ferrite: = 15,tan < 1.4E‐4,
H = 6Oe
Band gap
Band gap ..
2”
0.87”
0.8”
H 6Oe
H0 = 80kA/m
thickness = 100mil
•Novel MPC concept improves beneficial properties of DBE antennas:
–Close to optimal gain and bandwidth–Close to optimal gain and bandwidth–Broadside radiation pattern (suitable for phased arrays)–Smaller footprints (suitable for tightly packed arrays)
•21% footprint reduction with MPC Design (over DBE antenna)12% 14% B d id h I
42• Substrate: Rogers Duroid r = 2.2, tan = 0.0009• Ferrite inclusions: Calcium Vanadium-doped Garnet (CVG)
(4πMs = 1000G, ∆H = 6Oe).
•12%‐14% Bandwidth Improvement–For the thin substrate (d=100mil), 12% improvement–For the thick substrate (d=400mil), 14% improvement
Substrate Thickness EffectMPC, d = 100mil MPC, d = 200mil MPC, d = 300mil
MPC d = 400milMPC, d = 400mil
FBW = 0.7635%Gain = 6 2845dB
FBW = 2.2302%Gain = 6 5290dB
FBW = 3.8922%Gain = 6.4109dBGain 6.2845dB Gain 6.5290dB Gain 6.4109dB
FBW = 5.7554%Gain = 6.3185dB
DBE-2, d = 400mil
FBW = 5.0314%
43
Gain = 6.7626dB
MPC Antenna with Unbiased Ferrite Blocks
6 dB
Realized GainReflection
5.19 dB
6.23 dB
d~330 MHz shift
2.04 dB330 MHz shift
2.00 3.00 4.00Freq [GH z]2.467 3.465
2 467 3 4652 799 3 794
44
2.467 3.4652.799 3.794
Realized Gain with Biasing
5 76 dB5.76 dB
1.55 dB
‐0.03 dB
MPCresonanceat 2.35 GHz
Linearly polarized
45
Linearly polarizedBroadside radiation
Performance ComparisonsMPC
2”
2” 0.87”
DBE2”
2” 1 05”
Patch2”
2” 1 2”2
0.5”
0.8”0.87 2”
0 5”
0.92”1.05” 2”
1.3”1.2
0 5”0.5 0.5
All antennas are on 2”x2” finite ground planesg p
46
G/Q Footprint Comparison
DBE4” x 4”
PATCH1.8” x 1.8”
PATCH4” x 4”
r = 2.2
P i t d MPC
DBE
PATCH2” x 2”
PATCH
PATCH2” x 2”DBE
2” x 2”MPC
2” x 2”r = 9.6
Printed MPC 2” x 2”
unbiased
2” x 2”
DBE
PATCH1.2” x 1.2”(Elliptical)OSU-ESL double loop
Max. radius 6cm
DBE1.8” x 1.8”
DBE1 5” 1 5”
1.2” x 1.2”PATCH
1.5” x 1.5”
PATCH1.2” x 1.2”(Linear)
1.5” x 1.5”Iizuka-Hall Printed Antenna
10cm x 1cm (no GP)Iizuka-Hall Wire Antenna10cm x 1cm (no GP)
47
Future Radios will Likely be on Hybrid Substrates
RadioReceiver
Interconnects
Beamformer Design
between Silicon and Polymer
48
High speed data lanes overlaid on top of standard FR4 board targeting.
A SERDES I/O signaling over a backplane utilizing OTT interconnectsIssue: Limiting Speed due to
Interconnects
Interconnected ICs
a ba bPolymer data lanes
Passives/discrete ICs
M l i
Standard/low speed interconnectFR-4 board
Multi-processors
multi-chip bus connection. chip-to-chip link 49
Printing on Polymers is Challenging
• Printing on smooth PDMS surface (no surface modifications)
• Printing on microte t red PDMS
Cracks formed on metal surface
microtextured PDMS (only evaporation)
• Printing onPrinting on microtextured PDMS(evaporation and electroplating)
Peeling from PDMS surface• Printing on microtextured
d f difi dand surface modified composite surface 50
Transfer Molding/Lift-off and ElectroplatingLift-off negative mask in acetone
Transfer Molding
PDMS-Ceramic CompositePlastic negative mask on PDMS moldStamp Mold
Transfer Molding
PDMS-Ceramic Composite1μm
10-200 μmPDMS-Ceramic CompositeThin copper seed layer (~1 um)
PDMS-Ceramic Composite
Reactive Ion EtchingStamp Mold
PDMS-Ceramic Composite
PDMS-Ceramic Composite
Electroplating PDMS-Ceramic Compositep g
Negative pattern mask
M+M+ M+
Reference electrode Flexible, thick conduction lines on composite
Evaporated thin seed layer (cathode)
Polymer composite substrate
Copper electrode (Anode)Cu+2 sulfate-sulfuric acid solution 51
Flexible Microstrip Line Via ElectrodepositionMicro textured surface:Micro-textured surface: Flexible microstrip line:
74 mm
-0.1
0
0.1Measured insertion losses (S21)
-0.1
-0.05
0S21
-0.1
-0.05
0S21
-0.5
-0.4
-0.3
-0.2
dB-0.3
-0.25
-0.2
-0.15
dB
-0.3
-0.25
-0.2
-0.15
dB
0 9
-0.8
-0.7
-0.60 degree30 degree90 degree-30 degree-90 degree
0 5
-0.45
-0.4
-0.35
Printed TLsimulated PEC TL
0 5
-0.45
-0.4
-0.35
Printed TLsimulated PEC TL
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-0.9
frequency (GHz)0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
-0.5
frequency (GHz)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
-0.5
frequency (GHz)
Conducting loss: @ 1 GHzmdBmmmmdB /35.11000
741.0
High flexibility and high conductivity.52
Carbon Nanotube Printing on Polymer-Ceramic Composites
Carbon Nanotube/Silver coated textiles for integration into polymer-ceramicCarbon Nanotube/Silver coated textiles for integration into polymer ceramic composites.
Key features:• Mechanically very flexible & strong• Mechanically very flexible & strong• Strong adhesion with polymer-ceramic composites• Scalable production process•Comparable performance compared to traditional•Comparable performance compared to traditional antennas
•Developed E-textile patch gain was within 90% of the ideal PEC patch gain)--- Measured gain was 6dB at 2GHz (viz. 53
Direct CNT Printing on Polymer
Step 1: Grow Aligned CNTs on a Glass Substrate
Key Critical Parameters:• CNT Length• CNT Density• CNT Vertical Uniformity
Step 2: Spin Coating with Polymer Solution
Key Critical Parameters:• Spin Coating Rate• Polymer type (higher shrinkage rate
h d)when cured)
Step 3: Transfer to Larger Polymer SubstrateLarger Polymer Substrate
54
Step 1: Growing Aligned CNTsThis process involves using a quartz tubeThis process involves using a quartz tube.
1. Prepare the platform for the CNT (Si, SiO2 or Quartz)
Si, SiO2, Quartz etc.
Key Observations:
Length of CNTs are very criticalto achieving high conductivity.
b i id b
2. Deposit Catalyst (Fe)-Optionalto achieving high conductivity.We have found out that CNTswith about 100um length has the best conductivity characteristics.
Density of CNTs are very criticalto higher conductivity3. Grow Nanotubes inside Quartz Tube to higher conductivityWe found that the grow-process is very vitalto achieving denser aligned nanotubes. We developed our own process to achieve the best performance
Uniformity of CNTs in vertical C2H2CH Uniformity of CNTs in vertical
directionWe found out that CNTs tend to pull each other at the tips. Therefore, they have highercontact area. This leads to higher conductivity.In other words, we are using aligned CNT
t hi li d ti f hi h
Quartz Tube Furnace 79400 (1000 ºF)
CH4
process to achieve non-aligned tips for highercontact area.
55
Step 2: Spin Coating With Polymer
Take off the silicon wafer by Hydrofluoric (HF) acid
PDMS
Or peel it off
(Before Curing: Resistance is R0)
(After Curing: Resistance is R0/2)(After Curing: Resistance is R0/2)
Key Observations:
Curing leads to shrinkage in polymer, which in turn improves conductivity.
Higher shrinkage ratio is critical to achieving higher Higher shrinkage ratio is critical to achieving higher conductivity. For PDMS, it has about 2% shrinkage. For instance rubber has 4% which leads to 100% improvement in conductivity.
56
Carbon Nanotube Printing on Polymers for Layered Packaged Electronics?
• Over 6 dB Gain
10E-plane patternantenna layer:
microstrip patches,
antenna layer:
microstrip patches,
Within 1dB of the Perfectly Conducting Patch
5
0
5dipoles, bowties and etc.
feeding layer:
feeding networks, impedance tuning stubs
dipoles, bowties and etc.
feeding layer:
feeding networks, impedance tuning stubs
-15
-10
-5dB
circuits layer:
filters, mixers, LNAs and etc.
circuits layer:
filters, mixers, LNAs and etc.
-200 -150 -100 -50 0 50 100 150 200-25
-20
(degree)
58
Packaging Trends – A Bigger Challenge?
*Photo from StratEdge data sheet
• Low Cost IC’s Still Need Viable Packagingg g
• Likely bigger challenge than the chipset for MMW/THz
• Commercial Packaging extends toCommercial Packaging extends to MMW frequencies
– DC to 50+ GHz– Progress continues up in frequency
• Plastic Packages in use to ~30 GHz
59
Multi-physics, multi-domain co-simulation of system-in-package (SiP)
Working withProf Jin-Fa LeeProf. Jin-Fa Lee
60