Strategies for data acquisition using ultrasonic phased arrays
Phased-Arrays in Radio Communication Systems
Transcript of Phased-Arrays in Radio Communication Systems
Phased-Arrays in Radio Communication Systems
Prof. dr. ir. Bart Smolders
NXP Semiconductors, Nijmegen, The Netherlands
Eindhoven University of Technology (TU/e)
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Content
Trends in wireless communication systems
Examples of Phased-arrays in Communications– Cellular communication infrastructure– Satellite Reception and two-way communication– mm-Wave applications and Antenna-on-Chip
Conclusions
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Trend 1: Increase in bandwidth:Edholm’s LawFrom IEEE spectrum July 2004
Required Bandwidth/datarate doubles each 18 months
- Wireless growing faster than wired
-7 GHz available at 60 GHz
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Trend 2: Increase of operational frequency
1900 1920 1940 1960 1980 2000 202010
-3
10-2
10-1
100
101
102
Year
Freq
uenc
y [G
Hz]
Frequency vers us year of introduction
TVGSM
Satellite TV
AM
FM
Car radar
60 GHzWLAN
- Relative BW- Availability of new
bands- Next step sub-THz?
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Trend 3: Increase in power consumptionNeed for high-efficiency technologies
+12.500 windmills +50 conventional power plants
OR
Without changes only for cellular basestations we would need in the next 10-15 years:
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In Summary
Edholm’s law drives towards higher datarates– Shift to higher frequencies due to more absolute BW– Need for more efficient use of the available spectrum.
Phased-arrays can offer a solution here– Higher frequencies will require a high Antenna Gain and
electronic beam steering– Smart beamforming techniques offer higher datarates and
more frequency re-use.
But,– Communication systems require low cost.– Need for highly integrated solutions using Silicon-based IC
processes.
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Phased-arrays in cellular communication infrastructure
8© The International Engineering Consortium
Cellular Communication Infrastructure
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Cellular Communication Infrastructure
© The International Engineering Consortium
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Cellular Communication Infrastructure
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Cellular Communication Infrastructure
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Security fence
Equipment shelter
3G antennas
Electricity supply
Access road
2G antennas
Coaxial feeder cables
Point to point radio backhaul antenna
Backhaul cable
BTS (2G) Node B (3G)
Cell site efficiency =
< 4%
PRF
PDC
W-CDMA cell site efficiency
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|a1|exp(-jφ1) |a2|exp(-jφ2) |aK-1|exp(-jφK-1) |aK|exp(-jφK)
SUMMING NETWORK
S
s1 s2 sK-1 sK
z
WAVE FRONT
dx dx
Antennaelement
θ0
d xsinθ 0
1 2 K-1 K
Phased Array Concept
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Multiple beams and beamsteering
• Phased Arrays use multiple steered beams to eliminate fading effects.• Effective antenna gain depends on number of instantaneous users and their location.
• Beam steering requires lower output power, thereby saving energy.
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AC/DCConverter
Pin
220V85% 85%
DC/DCConverter
Idle48%
30%
PALow Power RF
DSPMicrowave linkBattery backup
Typical power balance without Phased-arrays
Pout
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AC/DCConverter
220V -48V +27V85% 85%
DC/DCConverter
Idle48%
30%
Example: Beam Steering with 6 dB extra average antenna gain: consumes 70 W iso 250 W for single antenna.
PALow Power RF
DSPMicrowave linkBattery backup
Beam steering antenna
Typical power balance with Phased Arrays
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Design basisstations with phased-arraysArtist impression Ericsson
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Phased-arrays in Satellite reception
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Current situation
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Drive for innovation in antenna concepts
Less “visible” antennas, especially in urban areas
Multi-beam requirements, reception of multiple satellite positions simultaneously.
Interference suppression by using beam-nulling techniques.
Most promising (low-cost) concepts:– Focal-plane arrays– Reflect-arrays
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-5 -4 -3 -2 -1 0 1 2 3 4 5-25
-20
-15
-10
-5
0
θ [deg]
Nor
mal
ised
arra
y pa
ttern
[dB
]
Modified pattern with interference nulling at +/- 2 degrees , f=11 GHz
Focal-plane Array for interference suppressionExample of reflector antenna with 3 feeds
Sat 1 Sat 3Sat 2
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ASTRA satellites and services
Orbital Position Satellite Use
50 E ASTRA 4AASTRA 1C
DTH services to Nordic countries and the Baltic, Eastern Europe, Ukraine, Russia.
19.20 E ASTRA 1FASTRA 1GASTRA 1H
ASTRA 1KRASTRA 1LASTRA 1M
DTH services to large audiences markets, e.g. Germany, France, Spain.
23.50 E ASTRA 3AASTRA 1E
DTH services for dynamic markets, e.g. Italy, Benelux, Central and Eastern Europe.ASTRA2Connect – Broadband Internet and
VoIP.
28.20 E ASTRA 2AASTRA 2BASTRA 2CASTRA 2D
DTH services to UK and Ireland.
31.50 E ASTRA 1D Cable TV distribution, Digital Terrestrial TV (DTT) and other terrestrial feeds
throughout Europe.
16 Satellites – 5 Orbital Positions
Specifications
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Reflect arrayLow-cost solution for multi-beam/beamsteering
A Ku-band demonstrator for Satellite DVB-TV was developed at the TU/e, using fixed beams
Next step to include MEMS phase-shifter for dynamic beam steering
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Reflect array, element design using low-cost patch antennas
Aperture Coupled Microstrip Antennas (ACMA)
• High Bandwidth• Space for microstrip line• Many degrees of freedom
Microstrip stub-length determinesphase-shift.
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Reflect array prototype, Antenna patterns
-80 -60 -40 -20 0 20 40 60 80-20
-10
0
10
20
30
40
50
X: 1Y: 35.49
X: 5.5Y: 35.42
X: -13.5Y: 33.9
X: 10Y: 35.19
THETA (degrees )
X: 13.5Y: 35.15
GAIN
(dB)
5 degrees19.2 degrees23.5 degrees28.2 degrees 31.5 degrees
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Phased-arrays in mm-wave applications
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Background-60GHz Applications
PAGE 272009-4-22
Source: IBM
• Need high-Gain antennas for link-budget• LOS communication, Need beam-steering
• 6 GHz Bandwidth• 2-10+ Gbps datarate
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1990 1995 2000 2005 2010 2015 202010
100
1000
Year
Tran
sit F
requ
ency
[GH
z]
RFCMOS SiGe BiCMOS
Ft of IC Technology vs Year [ITRS] & applications
Sat TV
24 GHzCar radar
60 GHzWLAN
77 GHzCar radar
94 GHzImaging
f T=2*f app
f T=10*f app
NXPQubic4Xi
ITRS= International Technology Roadmap for Semiconductors
20~30 GHzPoint to point
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How small can we make an antenna?Chu-Harrington fundamental limit
10-2
10-1
100
10-6
10-5
10-4
10-3
10-2
10-1
100
101
antenna s ize kr
Max
imum
Ban
dWid
th E
ffici
ency
pro
duct
Chu-Harrington fundamental limit of s mall antennas , BW*Eff
limit Dipole Goubau 1976 P atch S molders
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Cost of Antenna-on-Chip (AoC)
10 20 30 40 50 60 70 80 90 1000
5
10
15
20
25
Frequency [GHz]
Pric
e ad
der [
Eur
o ct
]
Antenna-on-chip P rice adder [Euro ct] vers us frequency
Normal Dipole BW=10% S mall antenna BW=0.2%
+ Lower test cost+ Lower package cost
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Silicon (Bi-)CMOS Technology stackTypical example
PAGE 312009-4-22
RV
AP
MZ
Substrate resistivity 15Ω.cm
ViaZ
Viax
POLY
M1
Mx
CO
• Typical 6-8 Metal layers• Thick metal 1-3 μm (top layers)• Substrate Res 10-200 Ohmcm• Wafer thickness 20-300 μm• Substrate modes are main issue
to address for efficiency and mutualcoupling
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60 GHz AoC prototype in Qubic4Xi technologyOverall Gain ~ 0 dBi
4.5 5 5.5 6 6.5 7
x 1010
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
frequency [Hz]S
11 [d
B]
Measured return loss
Advantages: - Reduced package, test and application cost- Higher performance due to direct matching antenna and electronics
1.5 mm
Paper accepted for publication at APS 2009
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Example of 4x1 integrated array in BiCMOS77 GHz 4x1 phased array transceiver with integrated antennas
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1. Edholms law drives towards more efficient use of available bandwidth and leads towards higher frequencies.
2. Phased-arrays will be needed in upcoming years.
3. Low-cost Silicon implementations will boost phased-arrays.
4. Examples have been presented:
• Cellular basestations,
• Satellite reception/two-way communications,
• AoC and AnoC for mm-wave applications.
5. It will take 5-10 years before phased-arrays will be high-volume technology in commercial radio applications.
Conclusions
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Thank You
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System-in-Package (SiP)Compleet Bluetooth systeem in 7x7 mm2
BGB204: Bluetooth Systeemzonder antenne in 7x7 mm2
Protoype met antenne in 155 mm2