THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 1
Yinggang Li, Mikael Hörberg and Jonas HansrydEricsson Research, Ericsson ABGöteborg, SwedenMarch 7, 2019
THz Point-to-Point Links:
>100 GHz; >100 Gbps
(Invited presentation at the 2nd THz Communication Workshop, Brussels Belgium)
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 2
Contents
• Background
• Spectrum Horizon
• Challenges
• Ex. D-band research and development
• Some future perspective
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 3
Global mobile traffic growth (based on measurement):
88%
(Total traffic = UL+DL including VoIP but DVB-H, Wi-Fi or Mobile WiMAX)
To
tal t
raff
ic (
Ex
ab
yte
/mo
nth
)
Ye
ar-
ov
er-
yea
r g
row
th (
%)
5G
LTE
WCDMA/HSPA
GSM/EDGE-only
Other
Smartphone subscriptions by technology
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 4
Transport networks
Evolving in: • Network dimensioning, architecture and topology
• Capacity
TRANSPORTBASEBAND
RADIO + SMALL CELL
RADIO SITE SYSTEM MANAGEMENT
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 5
Future transport needs
Source Ericsson (2018)
Backhaul capacity per site in Distributed RAN C2 (eCPRI) capacity in Centralized RAN
Urban
Suburban
Rural
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 6
Spectrum Horizon
In commercial use W-band, to be commercialized D-band, to be commercialized
5G candidate band 5G candidate band but prioritized for backhaul
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 7
Source: Ericsson Technology Review 2017, https://www.ericsson.com/assets/local/publications/ericsson-technology-review/docs/2017/etr-beyond-100ghz.pdf
46.5 GHz for wireless communication
The W-band and D-band
Deployment share per frequency(Source Ericsson 2017)
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 8
95
-1
00
10
2 -
10
9.5
11
1.8
-1
14
.25
12
2.2
5 -
12
3
5.0 7.5 2.45 0.75
13
0 -
13
4
4.0
14
1 -
14
8.5
7.5
15
1.5
-1
58
.5
7.0
17
4.5
-1
74
.8
0.3
23
1.5
-2
32
0.5
24
0 -
24
1
1.0
15
8.5
-1
64
16
7 -
17
4.5
19
1.8
-2
00
20
9 -
22
6
5.5 7.5 8.2 17.0
23
2 -
23
5
3.0
23
8 -
24
0
2.0
25
2 -
27
5
23.0
(a) Bands based on rules similar to E-band (70/80 GHz), totally 36 GHz
(b) Bands for licensed fixed wireless operations, totally 66.2 GHz
W-band
D-band
Higher bands
FCC Spectrum Horizon: up to 275 GHz proposed
(source: Ericsson/Yinggang Li)
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 9
Technical challenges when approaching sub-mmW:
• Output power varies generally as 1/f =23
• Packaging becoming increasingly difficult— if possible: integrate the antenna on-chip or in package
• Unwanted resonance modes may easily develop in MMIC substrate
• Modeling increasingly difficult at high frequency
• Phase noise increasing (typically 6 dB per frequency doubling)
• Receiver noise figure increasing
➔General statement: S/N degrades fast with frequency!
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 10
The solution must be: • Volume manufacturable
— Automatically assembly, repeatability (yield), tolerance insensitive, etc.
• Commercially affordable
How to transfer the “precious” mmW power from MMIC to antenna port?
on-wafer measured Psat
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 11
Example, D-band transceiver modules for PtP links
• M3TERA, a H20202 project
• PoC demonstrator: D-band Tx/Rx module
• MMICs in 130nm SiGe from Infineon (B11)
• Micromachined Si substrate as an heterogenous platform for system integration
Micromachined chip-to-antenna transition
PCB
Si platform
Metal fixture
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 12
Heterogenous integration based on micromachined Si substrate
• Micromachined low-loss Si waveguide
• Non-gavanic transition between MMIC and the waveguide
• Embedded components, e.g. BPF, duplexer and phase shifters
MEMS(Platform)
MEMS
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 13
Link test setup
13
Atten.
Rx2Tx3
SA
LO_Rx
LO_Tx
IF
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 14
CW test
14
-20.00
-15.00
-10.00
-5.00
0.00
5.00
10.00
-25.0 -22.5 -20.0 -17.5 -15.0 -12.5 -10.0 -7.5 -5.0 -2.5 0.0
TX
M o
utp
ut a
nd
ga
in
Input IF level (dBm)
TXM Pout (dBm)
TXM gain (dB)
FRF=130GHz
-30
-25
-20
-15
-10
-5
0
5
10
15
20
110.0 115.0 120.0 125.0 130.0 135.0 140.0 145.0
TXM
ou
tpu
t an
d g
ain
RF frequncy (GHz)
TXM Pout (dBm)
TXM gain (dB)
PIF = -15 dBm
-10
-5
0
5
10
15
20
110 115 120 125 130 135 140 145 150
TX-R
X G
ain
RF frequency (GHz)
IF= 1333MHz
— Peak gain position (frequency) depend strongly on bias
— Bandwidth depends strongly on bias
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 15
Real-time data transmission based on Ericsson’s Modem
15
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 16
Measurement results
16
1.0E-12
1.0E-11
1.0E-10
1.0E-09
1.0E-08
1.0E-07
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
-55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5
BER
Received power to RXM (dBm)
channel width:
250 MHz
QPSK
16QMA
64QAM
1.0E-12
1.0E-11
1.0E-10
1.0E-09
1.0E-08
1.0E-07
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
-55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5
BER
Received input power to RXM (dBm)
For 16QAM 125MHz
250MHz
750MHz
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 17
100 Gbps microwave link is not a
dream any more today but a
reality!
• Demonstrated by Ericsson in
Gothenburg, Feb. 2019
• Based on Ericsson’s existing
commercial product
• Line-of-sight MIMO plus H/V
polarization
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 18
8-channel PtP LoS-MIMO, 100 Gbps
Purposely removed!
THz point-to-point links | © Ericsson AB | 7th March 2019 | Page 19
Looking forward• > 100 GHz
— Short-term: W- & D-band
— Longer term: towards sub-mmW (275 GHz)
• > 100 Gbps — Microwave solutions available today to meet the need for 5G
towards 2025
— 100 Gbps for beyond 5G towards 2030(Tbps from even longer-term perspective ?)
• Compact and simplified site solution for MIMO and high-gain antennas towards sub-mmW
• Challenges with THz MMIC interconnect and packaging— Heterogenous system integration
— Antenna-in-package and SiP
➔Continuous and sustained research effort is necessary to commercialize the mmW-THz spectrum Perspective for future D-band LoS-MIMO