Trends in wireless communication systems. Examples of Phased-arrays in
Communications. – Cellular communication infrastructure. – Satellite Reception
and two-way communication. – mm-Wave ... From IEEE spectrum July 2004.
Required ...
Phased-Arrays in Radio Communication Systems Prof. dr. ir. Bart Smolders NXP Semiconductors, Nijmegen, The Netherlands Eindhoven University of Technology (TU/e)
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
2
Trend 1: Increase in bandwidth:Edholm’s Law From IEEE spectrum July 2004
- Wireless growing faster than wired -7 GHz available at 60 GHz
Required Bandwidth/datarate doubles each 18 months 3
Trend 2: Increase of operational frequency 10
Frequency vers us year of introduction
2
60 GHz WLAN Car radar
Frequency [GHz]
10
10
Satellite TV
1
- Relative BW - Availability of new bands - Next step sub-THz?
0
TV GSM
10
10
FM
-1
-2
-3
AM
10 1900
1920
1940
1960 Year
1980
2000
2020
4
Trend 3: Increase in power consumption Need for high-efficiency technologies Without changes only for cellular basestations we would need in the next 10-15 years:
OR
+12.500 windmills
+50 conventional power plants 5
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.
6
Phased-arrays in cellular communication infrastructure
7
Cellular Communication Infrastructure
© The International Engineering Consortium
8
Cellular Communication Infrastructure
© The International Engineering Consortium
9
Cellular Communication Infrastructure
10
Cellular Communication Infrastructure
11
W-CDMA cell site efficiency PRF Cell site efficiency =
2G antennas
PDC
< 4%
Point to point radio backhaul antenna
3G antennas Coaxial feeder cables Equipment shelter
Electricity supply Security fence Access road Backhaul cable
BTS (2G)
Node B (3G)
12
Phased Array Concept
z
θ0
W
AV
EF
RO
NT
s1 |a1|exp(-jφ1)
dx
K-1
s2
sK-1
|a2|exp(-jφ2)
K
d
2
1
x si
nθ 0
Antenna element
|aK-1|exp(-jφK-1)
dx
sK |aK|exp(-jφK)
SUMMING NETWORK S
13
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.
14
Typical power balance without Phased-arrays AC/DC Converter Pin
DC/DC Converter
85%
220V
85% 30%
Low Power RF DSP Microwave link Battery backup
PA Idle
48% Pout
15
Typical power balance with Phased Arrays AC/DC Converter
85% 220V
DC/DC Converter -48V
Low Power RF DSP Microwave link Battery backup
85% +27V
30% PA
48%
Idle
Example: Beam Steering with 6 dB extra average antenna gain: consumes 70 W iso 250 W for single antenna.
Beam steering antenna
16
Design basisstations with phased-arrays Artist impression Ericsson
17
Phased-arrays in Satellite reception
18
Current situation
19
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
20
Focal-plane Array for interference suppression Example of reflector antenna with 3 feeds Sat 2 Modified pattern nulling at +/- 2 degrees Sat with 1 interference Sat 3 , f=11 GHz 0
Normalis ed array pattern [dB]
-5
-10
-15
-20
-25 -5
-4
-3
-2
-1
0 θ [deg]
1
2
3
4
5
21
ASTRA satellites and services Specifications 16 Satellites – 5 Orbital Positions Orbital Position
Satellite ASTRA 4A ASTRA 1C
Use DTH services to Nordic countries and the Baltic, Eastern Europe, Ukraine, Russia.
19.20 E
ASTRA 1F ASTRA 1G ASTRA 1H ASTRA 1KR ASTRA 1L ASTRA 1M
DTH services to large audiences markets, e.g. Germany, France, Spain.
23.50 E
ASTRA 3A ASTRA 1E
DTH services for dynamic markets, e.g. Italy, Benelux, Central and Eastern Europe. ASTRA2Connect – Broadband Internet and VoIP.
28.20 E
ASTRA 2A ASTRA 2B ASTRA 2C ASTRA 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.
50 E
22
Reflect array Low-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 23
Reflect array, element design using lowcost patch antennas Microstrip stub-length determines phase-shift.
Aperture Coupled Microstrip Antennas (ACMA) • High Bandwidth • Space for microstrip line • Many degrees of freedom
24
Reflect array prototype, Antenna patterns
50 5 de gre e s 19.2 de gre e s 23.5 de gre e s 28.2 de gre e s 31.5 de gre e s
40 X: -13.5 Y: 33.9
X: 1 Y: 35.49 X: 5.5 Y: 35.42
X: 10 Y: 35.19 X: 13.5 Y: 35.15
30
GAIN(dB)
20
10
0
-10
-20
-80
-60
-40
-20
0 THE TA (de gre e s )
20
40
60
80
25
Phased-arrays in mm-wave applications
26
Background-60GHz Applications • 6 GHz Bandwidth • 2-10+ Gbps datarate
• Need high-Gain antennas for link-budget • LOS communication, Need beam-steering
Source: IBM 27 2009-4-22
PAGE 27
Ft of IC Technology vs Year [ITRS] & applications
Transit Frequency [GHz]
1000 NXP Qubic4Xi 94 GHz Imaging
100
77 GHz Car radar 60 GHz WLAN
p *f ap 0 1 f T=
20~30 GHz Point to point 24 GHz Car radar Sat TV
10
* f ap 2 f T=
1990
RFCMOS SiGe BiCMOS
p
1995
2000
2005 2010 Year
2015
2020
ITRS= International Technology Roadmap for Semiconductors
28
How small can we make an antenna? Chu-Harrington fundamental limit 10
Maximum BandWidth Efficiency product
10
10
10
10
10
10
10
Chu-Harrington fundamental limit of s mall antennas , BW*Eff
1
limit Dipole Goubau 1976 P atch S molders
0
-1
-2
-3
-4
-5
-6
10
-2
-1
10 antenna s ize kr
10
0
29
Cost of Antenna-on-Chip (AoC) Antenna-on-chip P rice adder [Euro ct] vers us frequency 25 Normal Dipole BW=10% S mall antenna BW=0.2%
P rice adder [Euro ct]
20
15
+ Lower test cost + Lower package cost 10
5
0 10
20
30
40 50 60 Frequency [GHz]
70
80
90
100
30
Silicon (Bi-)CMOS Technology stack Typical example
AP
• 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 mutual coupling
RV MZ
ViaZ Mx Viax M1
CO POLY
Substrate resistivity 15Ω.cm
31 2009-4-22
PAGE 31
60 GHz AoC prototype in Qubic4Xi technology Overall Gain ~ 0 dBi Measured return loss -2 -4 -6
1.5 mm
S 11 [dB]
-8 -10 -12 -14 -16 -18 -20 4.5
5
5.5
6
fre que ncy [Hz]
6.5
7 x 10
Advantages: - Reduced package, test and application cost - Higher performance due to direct matching antenna and electronics Paper accepted for publication at APS 2009
32
10
Example of 4x1 integrated array in BiCMOS 77 GHz 4x1 phased array transceiver with integrated antennas
33
Conclusions 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 highvolume technology in commercial radio applications.
34
Thank You
35
System-in-Package (SiP) Compleet Bluetooth systeem in 7x7 mm2
BGB204: Bluetooth Systeem zonder antenne in 7x7 mm2
Protoype met antenne in 155 mm2
36
