Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
IBM Research
© 2018 IBM Corporation
Millimeter-Wave Phased Array for 5G
Alberto Valdes-Garcia
Research Staff Member, Manager
IBM T. J. Watson Research Center
Yorktown Heights, NY
1
IBM Research
© 2018 IBM Corporation
Use case scenario for mmWave directional 5G
communications involving pico-cells with phased arrays:
mmWave-based 5G network concept:
Ericsson: E. Dahlman, et al., “5G Radio Access,” Ericsson Review, June, 2014
Samsung: W. Roh, et al., "Millimeter-wave beamforming as an enabling technology for 5G cellular communications:
theoretical feasibility and prototype results," in IEEE Comm. Magazine, Feb, 2014
2
IBM Research
© 2018 IBM Corporation
4 in.
Discrete 60-GHz Radio World’s 1st monolithic mmWave RadioIBM Research. ISSCC 2006
Cost: $1,500
Size: 10’s of cm
Cost: ~$15
Size: <10 mm
Enabling technology #1: Silicon integration of mmWave
transceivers
Miniaturization and mass adoption of mmWave
applications
3
IBM Research
© 2018 IBM Corporation
Beam steering acheived by varying delay in each
element
t
2t
3t
4t
With N element TX, if each element radiates P Watts,
Effective radiated power in target direction: N2.P Watts.
Enabling technology #2: Integrated phased arrays for
beam formingDelay
4t
4t
4t
4t
Lower interference
due to incoherent
addition of signals.
Higher power at
targeted receiver due to coherent addition
of signals.d=l / 2
=
l
t
c2sin 1
c.t = d.sinθ
A. Natarajan, et al., JSSC 2005
4
IBM Research
© 2018 IBM Corporation
14+ Year History of mmWave Subsystem Research at IBM
94-GHz 64-element Phased
Array Transceiver60GHz 16-Element Phased Array
Transceiver Chip-Set
Leading-edge highly-integrated technology solutions to enable wireless communication and sensor
systems with less volume, weight and cost
World’s First Monolithic
mmWave (60 GHz) Radio
Low-power,
Switched Beam
60GHz CMOS IC
20112005 20132003 2007 2009 2015
60-GHz Low-Power Radio in 32nm SOI
60-GHz SiGe Single-Element and Phased Array Radios
94-GHz Scalable Phased Array
E-band Fixed-Beam Radio for Backhaul
5G
2017
28-GHz 64-element
Phased Array
Transceiver
IBM Research
© 2018 IBM Corporation
This Presentation: 28-GHz Phased Array Antenna Module co-developed by IBM Research and Ericsson
TX H/TX V
IBM Research
© 2018 IBM Corporation7
Key mmWave 5G implementation challenges
Key mmWave 5G picocell challenges
Phased array IC design challengesAntenna and package design
challenges
Maximize TX range while minimizing form factor
Maximize TX output power, with TX/RX integration
Integrate multiple RFICs enabling array scalability
Ease of beam-forming and beam-control
Orthogonal phase and gain control at each front-end
Implement a wide-band antenna element with equal-length feed lines
High beam steering resolution over wide range scan range
Fine phase resolution in phase shifterBalance antenna gain and element pattern;
Maintain antenna uniformity
Support for simultaneous beams
Support for two polarizations at IC level Support dual-polarized antennas and configurable beams at module level
The performance requirements associated with mmWave 5G mobile communications
are significantly more challenging than those posed by prior indoor/WLAN mmWave
communication usage scenarios
IBM Research
© 2018 IBM Corporation8
Orthogonal Gain & Phase Control
• Transmit/receive frontend‐ Phase invariant gain control
‐ Loss invariant phase shift
.
IBM Research
© 2018 IBM Corporation9
Limited phase resolution produces a
periodic degradation in the sidelobe
suppression versus steering angle. While
attempting ∼20-dB sidelobe suppression
using a Taylor window tapering function
A phase resolution of 5° is an attractive target
as it results in beam pointing with <1° beam
steering resolution with sidelobe suppression
levels within ∼1 dB of an ideal phase shifter
when attempting 20 dB sidelobe suppression.
Effect of Phase Resolution on Beam Steering for an 8X8Array
.
IBM Research
© 2018 IBM Corporation10
Tunable Transmission Line as a Phase Shifter: Concept
Low Delay = 𝐿1𝐶1
High Delay = 𝐿2𝐶2
𝐿1𝐶1
=𝐿2𝐶2
= 𝑍𝑜
Constant characteristic
impedance:
Small L, small C
Large L, large C
.
ejωt
ej(ωt-kx)
Zo
L
C C
L L
C
W. H. Woods, A. Valdes-Garcia, H. Ding, and J.Rascoe, “CMOS Millimeter Wave Phase Shifter Based onTunable Transmission Lines”, IEEE Custom Integrated Circuits Conference, pp. 1-4, September 2013.
IBM Research
© 2018 IBM Corporation11
Dual-polarized IC Architecture: Single Polarization Slice
5.2GHz LO
3GHz TX IF
3GHz RX IF
B. Sadhu, et al, "A 28GHz 32-Element Phased-Array Transceiver IC with Concurrent Dual Polarized Beams and 1.4 Degree Beam-Steering Resolution for 5G Communication", IEEE ISSCC, 2017.
.
IBM Research
© 2018 IBM Corporation12
Dual-polarized IC Architecture: Two Identical 16-Element
Slices
5.2GHz LO
3GHz H/V TX IF
3GHz H/V RX IF
.
IBM Research
© 2018 IBM Corporation13
5.2GHz LO
3GHz H/V TX IF
3GHz H/V RX IF
Dual-polarized IC Architecture: Two Identical 16-Element
Slices. 32 Elements Feed 16 Dual-Pol Antennas
.
IBM Research
© 2018 IBM Corporation14
IC Implemented in SiGe 130nm BiCMOS: fT/fMAX =
200GHz/280GHz
H & V pol TX & RX
IF-RF conversion
8 H & V pol. TRX FEs
15.8mm
10
.5m
m
Cen
tral
Dig
ital
8 H & V pol. TRX FEs
.
IBM Research
© 2018 IBM Corporation15
TRX Front-End H-Polarization
PA
LNA + T/R SW
TX Phase Invariant VGA and Phase
Inverter
RX Phase Invariant VGA and Phase
Inverter
TX/RX SW
T-line based 180o phase shifter
l/4 ESD
28-GHz Dual-polarized TRX Front-End Breakout 32 TX, 32 RX, 28-GHz Phased Array IC
Front-End: Physical Design
.
IBM Research
© 2018 IBM Corporation16
On-wafer Measurement Results Summary
Single TX Path in Full IC:27 Front-Ends Across 9 ICs
.
B. Sadhu et al., “A 28-GHz 32-Element TRX Phased-Array IC With Concurrent Dual-Polarized Operation and Orthogonal Phase and Gain Control for 5G Communications”, IEEE Journal of Solid-State Circuits, Vol, 52, pp. 3373-3391, December 2017.
IBM Research
© 2018 IBM Corporation
Antenna-in-package Array with Air Cavity
X. Gu, D. Liu, C. Baks, O. Tageman, B. Sadhu, J. Hallin, L. Rexberg, and A. Valdes-Garcia, " A Multilayer Organic Package with 64 Dual-Polarized Antennas for 28GHz 5G Communication", IEEE IMS, June 2017.
• Aperture coupled patch
antenna
• Uniform air cavity between
antenna patch and feed
structure
• 14-layer base substrate
based on organic buildup
technology
Key Features:
17
IBM Research
© 2018 IBM Corporation
Why We Need Air Cavity
No-cavity antennas (e.g., a probe-fed stacked patch antenna)
Limited bandwidth
Stronger surface waves, poor efficiency and radiation patterns due to more EM
energy trapped in substrate
D. Liu, et al. “Antenna-in-Package Design Considerations for Ka-band 5G Communication Applications”, IEEE T-AP, 2017.
0.7GHz Bandwidth @ -10dB
18
IBM Research
© 2018 IBM Corporation
Scalability Approach
As compared to a single-polarized TX RX chipset implementation in Option 1, Option 4
achieves a 4× reduction in area of the package. This makes Option 4 a compact, practical
approach for a dual polarized millimeter-wave 5G phased-array solution.
19
IBM Research
© 2018 IBM Corporation
Scalability Approach Tradeoffs
20
IBM Research
© 2018 IBM Corporation
Fully-Assembled 4-chip Antenna Module
Package dimensions: 70mm x 70mm x 2.7mm
Flip-chip assembly for 4 ICs
• 655 BGA w/ 1.27mm pitch supporting multiple power domains, IF (TX & RX) and LO signals, Digital control and ref clock signals
Phased array IC and package scalability concept introduced and demonstrated at
94GHz in A. Valdes-Garcia, et al., RFIC 2013 and X. Gu, et al. ECTC 2014
21
IBM Research
© 2018 IBM Corporation
5.2GHz LO signal
3GHz IF signals(TX H/V and RX H/V)
Over the Air Measurement Setup Using 4 IC Module
Evaluation board
Antenna chamber set-up22
IBM Research
© 2018 IBM Corporation23
Measured 64 Element Progressive Element Turn On Without
Calibration
Measu
red =
35dB
20lo
g(6
4) =
36dB
Measured saturated
EIRP in one
polarization = 54dBm
.
IBM Research
© 2018 IBM Corporation24
Measurements of 16 Element Beams from 1 IC
2 simultaneous beams in RX mode
2 simultaneous beams in TX mode
Results
obtained
without
requiring array
calibration
Measured radiation patterns
Ideal radiation patterns calculated with the same angular resolution available in the measurement setup
.
IBM Research
© 2018 IBM Corporation25
Beam steering + gain control
Measured Beam Steering Control
Beam steering Gain control
Pointing error
Results
obtained
without
requiring array
calibration
.
IBM Research
© 2018 IBM Corporation26
Beam steering + gain control
Gain controlBeam steering
Pointing error
Measured Beam Steering Control
Results
obtained
without
requiring array
calibration
.
IBM Research
© 2018 IBM Corporation27
Beam steering
Pointing error
Beam steering + gain control
Gain control
Measured Beam Power Control
Results
obtained
without
requiring array
calibration
.
IBM Research
© 2018 IBM Corporation28
Beam-Forming Options in TX/RX
Total TRX elements per module (4 ICs) = 128
8 16-
element
beams
2 64-element
beams
.
IBM Research
© 2018 IBM Corporation29
Measurements of Reconfigurable Beams from a Module
(4 ICs)
IC 1-4 RX H/RX V
IC1-V
IC1-H
IC2-V
IC2-H
IC3-H
IC3-V
IC4-H
IC4-V
TX H/TX V
8 16-element beams 2 64-element beams
Results
obtained
without
requiring array
calibration
.
IBM Research
© 2018 IBM Corporation
Measurement of 64-element Beam Steering Patterns
Hpol Hplane Hpol Eplane
Lower than 10dB side lobe level (over ±40°) without tapering and calibration
30
IBM Research
© 2018 IBM Corporation
Hpol Hplane
64-element Beam Pattern: Model-to-Hardware Correlation
- - - Measurement___ Simulation
• Identical PA bias setting for all front-
ends in measurement
• 12° half-power beam width; < -12dB
side lobe level; over 20dB notch
(without amplitude calibration or
tapering)
31
IBM Research
© 2018 IBM Corporation
Hpol Eplane
64-element Beam Pattern: Model-to-Hardware Correlation
- - - Measurement___ Simulation
• Full-wave EM simulation on a
complete package
• Simulation excitation assumes
an ideal IC output
• Measurements match
accurately with simulations - a
nearly ideal beam pattern and
predictability of the design
32
IBM Research
© 2018 IBM Corporation
E-plane H-plane
Measured 64-element Beam Steering (H-pol, ±50°)
33
IBM Research
© 2018 IBM Corporation
Measured 64-element Beam Steering (V-pol, ±50°)
E-plane H-plane
34
IBM Research
© 2018 IBM Corporation
Tapering Measurement Results
Measurement is performed in RX mode with 64 elements in H pol
Tapering uses VGA control and Taylor window
35
IBM Research
© 2018 IBM Corporation36
Measured Beam Switching Speed
Beam switching
speed is <4ns4ns 4ns
Ou
tput
sig
nal envelo
p (
V)
Ou
tput
sig
nal envelo
p (
V)
.
IBM Research
© 2018 IBM Corporation37
Measured TXRX Switching Speed
TXRX switching
speed is <100ns90ns 100ns
.
IBM Research
© 2018 IBM Corporation38
Performance Summary and Comparison for Published 28GHz
Si-based Packaged Phased-Array TRXReference UCSD, RFIC 17’ UCSD, IMS 17’ LG, RFIC 17’ This work [ISSCC, IMS 17’]
Frequency (GHz) 29 29 28 28
Elements per chip 4TRX 4TRX 8TRX 32TRX
Elements in package 32TRX 4TRX 8TRX 128TRX
Concurrent TX/RX polarizations 1 1 1 2
Phase resolution () 5.6 5.6 45 5
RMS phase error () 6 6 7 0.8
TX Psat (dBm) per element 13 __ 10.5 16
TX Op1dB (dBm) per element 11.7 10.5 __ 13.5
Peak TX efficiency (total chip output power /
dissipated power) (%)7.4 5.6 13.2 13.8
TX EIRP per package per pol. @Psat (dBm) 41 __ 31.5 54
Die area (mm2) 11.7 11.7 7.3 166
Technology (nm)180nm
SiGe180nm SiGe
28nm
CMOS130nm SiGe
Integration level Antenna on PCB Antenna on PCB AiP AiP
.
IBM Research
© 2018 IBM Corporation39
.
Initial Link Test
IBM Research
© 2018 IBM Corporation
Outdoor Link Measurements at IBM T.J.W. Research Center
1
23
50m
28-GHz 64-Element Phased Array + Test Equipment:
• Verizon pre-5G spec (5G TF)
• URL: http://www.5gtf.org
• 8 x 100MHz channels, 64 QAM, 0.2ms per sub-frame
40
IBM Research
© 2018 IBM Corporation
Measured RMS EVM as a function of active TX/RX elements
50m LOS link
0
2
4
6
8
10
12
14
0 20 40 60 80
EV
M [
%]
Number of Active TX Elements
Measured Min/Max link RMS EVM across 8 100MHz carriers
RX active elements = 64
Min EVM
Max EVM
0
2
4
6
8
10
12
0 10 20 30 40 50 60 70
EV
M [
%]
Number of Active RX Elements
Measured Min/Max link RMS EVM across 8 100MHz carriers
TX active elements = 64
Min EVM
Max EVM
EVM ~11% or better is maintained across all carriers with either 16TX Elements and 64 RX
elements or 8 RX elements and 64 TX elements
41
IBM Research
© 2018 IBM Corporation
Measured RMS EVM as a function of active TX/RX elements
19m LOS link through glass
0
2
4
6
8
10
12
14
0 20 40 60 80
EV
M [
%]
Number of Active RX Elements
Measured Min/Max link RMS EVM across 8 100MHz carriers
TX active elements = 64
Min EVM
Max EVM
0
2
4
6
8
10
12
14
16
0 20 40 60 80
EV
M [
%]
Number of Active TX Elements
Measured Min/Max link RMS EVM across 8 100MHz carriers
RX active elements = 64
Min EVM
Max EVM
EVM ~11% or better is maintained across all carriers with either 8TX Elements and 64 RX
elements or 8 RX elements and 64 TX elements
42
IBM Research
© 2018 IBM Corporation43
Summary and Conclusions
• First reported mmWave 5G base-station IC in a multi-IC antenna-in-package
• Orthogonal phase and amplitude control for efficient beam control
• High resolution beam steering with low side-lobes based on fine phase shift resolution
• Introduced novel built-in air cavity to optimize antenna array performance
• Demonstrated an organic multilayer package with 4 transceiver ICs and 64 dual polarized antenna elements for 28GHz communication
• Wireless links demonstrated with Verizon pre-5G spec
.
NEXT: “A Software-Defined Phased Array Radio with mmWave to Software
Vertical Stack Integration for 5G Experimentation”, IEEE IMS 2018, June 14th
IBM Research
© 2018 IBM Corporation44
Acknowledgments
B. Sadhu1, Y. Tousi1, J. Hallin2, S. Sahl2, S. Reynolds1, Ö. Renström2,
K. Sjögren2, O. Haapalahti2, N. Mazor1, B. Bokinge2, G. Weibull2, H.
Bengtsson2, A. Carlinger2, E. Westesson2, J.-E. Thillberg2, L.
Rexberg2, M. Yeck1, D, Friedman1, A. Valdes-Garcia1, M. Soyuer1, C.
Baks1, D. Liu1, Y. Kwark1, M. Wahlen2, A. Ladjemi2, A. Malmcrona2, P.
Parida1, Y. Kwark1, M. Ferriss1, N. Boyer1, E. Giguere1, S.
Vecchiattini2, R. Lindman2, A. Ljungbro2, E. Pucci2
1IBM2Ericsson
.
IBM Research
© 2018 IBM Corporation
Ultimately though, we should expect mmWave systems to become as inexpensive and ubiquitous as 2.4-and 5-GHz WLAN systems are today. Some of the early companies developing products in the mmWave
space will succeed and become profitable, and some will fail. But the end result will be“millimeter-waves for the masses” - Advanced Millimeter Wave Technologies: Antenna, Packagingand Circuits, Wiley Press, 2009
45
IBM Research
© 2018 IBM Corporation
References1. B. Sadhu, Y. Tousi, J. Hallin, S. Sahl, S. K. Reynolds, Ö. Renström, K. Sjögren, O. Haapalahti, N. Mazor, B. Bokinge, G. Weibull, H.
Bengtsson, A. Carlinger, E. Westesson, J.-E. Thillberg, L. Rexberg, M. Yeck, X. Gu, M. Ferriss, D. Liu, D. Friedman, and A. Valdes-
Garcia, “A 28-GHz 32-Element TRX Phased-Array IC With Concurrent Dual-Polarized Operation and Orthogonal Phase and Gain
Control for 5G Communications”, IEEE Journal of Solid-State Circuits, Vol, 52, pp. 3373-3391, December 2017.
2. D. Liu, X. Gu, C. W. Baks, and A. Valdes-Garcia, “Antenna-in-Package Design Considerations for Ka-band 5G Communication
Applications”, IEEE Transactions on Antennas and Propagation, Vol. 65, No. 12, pp. 6372-6379, December 2017.
3. X. Gu, D. Liu, C. Baks, O. Tageman, B. Sadhu, J. Hallin, L. Rexberg, and A. Valdes-Garcia, " A Multilayer Organic Package with 64
Dual-Polarized Antennas for 28GHz 5G Communication", IEEE International Microwave Symposium, pp/ 1899-1901, June 2017.
4. B. Sadhu, Y. Tousi, J. Hallin, S. Sahl, S. Reynolds, O. Renstrom, K. Sjorgren, O.Haapalahti, N. Mazor, B. Bokinge, G. Weibull, H.
Bengttson, A. Carlinger, E. Westesson5, J.-E. Thillberg, L. Rexberg, X. Gu, Daniel Friedman, and A. Valdes-Garcia, "A 28GHz 32-
Element Phased-Array Transceiver IC with Concurrent Dual Polarized Beams and 1.4 Degree Beam-Steering Resolution for 5G
Communication", IEEE International Solid-State Circuits Conference, February 2017.
5. Y. Tousi and A. Valdes-Garcia, “A Ka-band Digitally-Controlled Phase Shifter with sub-degree Phase Precision”, IEEE Radio Frequency
Integrated Circuits Symposium, pp. 356-359, May 2016.
6. B. Sadhu, J. Bulzzachelli, and A. Valdes-Garcia, “A 28GHz SiGe BiCMOS phase invariant VGA”, IEEE Radio Frequency Integrated
Circuits Symposium, pp. 319-322, May 2016.
7. W. H. Woods, A. Valdes-Garcia, H. Ding, and J.Rascoe, “CMOS Millimeter Wave Phase Shifter Based onTunable Transmission Lines”,
IEEE Custom Integrated Circuits Conference, pp. 1-4, September 2013.
8. A. Valdes-Garcia, A. Natarajan, D. Liu, M. Sanduleanu, X. Gu, M. Ferriss, B. Parker, C. Baks, J.-O. Plouchart, H. Ainspan, B. Sadhu, Md.
R. Islam, and S. Reynolds, ”A Fully-Integrated Dual-Polarization 16-Element W-band Phased-Array Transceiver in SiGe BiCMOS", IEEE
Radio Frequency Integrated Circuits Symposium, pp. 375-378, June 2013.
46
IBM Research
© 2018 IBM Corporation47
28-GHz Tunable T-line Phase Shifter Implementation
>180 deg. phase range
Small phase steps: 4.7 deg.
Uniform phase steps: <1
deg. RMS phase error
Fast switching: <5 ns
.
L SC L
L
L
SC L
Y. Tousi and A. Valdes-Garcia, “A Ka-band Digitally-Controlled Phase Shifter with sub-degree Phase Precision”, IEEE Radio Frequency Integrated Circuits Symposium, pp. 356-359, May 2016.
Key Features:Low
delay
High
delay
IBM Research
© 2018 IBM Corporation48
Phase Invariant Gain Control
Gain
control
Used for phase
invariance𝑅𝑒0 =
𝑐𝜋𝑔𝑚𝑐𝑗𝑒
=𝜏𝑏𝑐𝑗𝑒 < ±2
8dB
B. Sadhu, J. Bulzzachelli, and A. Valdes-Garcia, “A 28GHz SiGe BiCMOS phase invariant VGA”, IEEE Radio Frequency Integrated Circuits Symposium, pp. 319-322, May 2016.
.
IBM Research
© 2018 IBM Corporation
Air Cavity Based Dual-polarized Antenna
X. Gu, D. Liu, C. Baks, O. Tageman, B. Sadhu, J. Hallin, L. Rexberg, and A. Valdes-Garcia, " A Multilayer Organic Package with 64 Dual-Polarized Antennas for 28GHz 5G Communication", IEEE IMS, June 2017.
• Aperture coupled patch
antenna
• Uniform air cavity between
antenna patch and feed
structure
• 14-layer base substrate
based on organic buildup
technology
49