17
Development Activity of Terahertz Power Amplifiers -W-band to 300GHz-
6
th
Japan-EU Symposium on ICT Research
and Innovation at Makuhari Messe
Development Activity of Terahertz Power Amplifiers-W-band to 300GHz-
Oct. 7, 2016
NEC Network and Sensor Systems, Ltd.
Microwave Tubes Division
○Norio Masuda, Mitsuru Yoshida, Koji Okamoto
Agenda
1. Introduction of our TWT
2. TWT for wireless
communications and power
modules
3. Other applicationThis work was supported in part by R&D on amplifier
technology in 300 GHz band, in a part of R&D program
on key technology in terahertz frequency bands of the
Ministry of Internal Affairs and Communications, Japan.
4 © NEC Corporation 2015 NEC Group Internal Use Only4 © NEC Network and Sensor System, Ltd. 2016
Expected Applications
Fixed to Mobile
� High–data-rate
Communication Network
� Imaging Systems
Autonomous Driving
Non-destructive Inspection
Safety & Security
(Walking trough)
Fixed Wireless Links
THz signal
5 © NEC Corporation 2015 NEC Group Internal Use Only5 © NEC Network and Sensor System, Ltd. 2016
Frequency(THz)
10
4
10
3
10
1
10
-2
10
-1
10
-3
Microwave tubes
10
2
10
0
10
5
Radar
(TWT/KLY/MAG
/CFA)
Limits of Combined
Solid State Amplifiers
Competitive
W JKu/K/Ka
THz apps.
(TWT)
Earth station
（TWT/KLY/HPA）
Satellite
Term./FWA
（MPM/MMPM）
Power Limits
of Single
Device
(Solid State)
Limits of
microwave
tubes
Review of Amplifier Devices
10
0
10
1
[THz]
110
-1
10
2
[W]
（Atmospheric
Attenuation）
（Review of Power Module）
Space
（TWT/MAG/HPA）
0.3THz
Target
0.1THz
(NETS)
Solid state
MAG: Magnetron
KLY: Klystron
CFA: Cross Field Device
FWA: Fixed Wireless Access
MPM: Microwave Power Module
MMPM: Millimeter wave Power Module
Introduction of our TWT
7 © NEC Corporation 2015 NEC Group Internal Use Only7 © NEC Network and Sensor System, Ltd. 2016
TWT
（IEEE Trans. Electron Devices, 52, 5, 660-664）
TWT：Traveling Wave Tube
� Classified in Microwave Vacuum Devices (MVEDs)
� Achieve a high degree of amplification by interaction
between electron beam and electromagnetic wave*
� Small and simple device structure, High efficiency, High
power in high frequencies
*Bring electromagnetic wave into sync with electron beam.
Example of TWT
Millimeter wave power module
8 © NEC Corporation 2015 NEC Group Internal Use Only8 © NEC Network and Sensor System, Ltd. 2016
Satellite
relay
vehicle
Power module for
satellite relay vehicle
SNG (Satellite News Gathering)
Earth station
（Broadcasting Satellite System）
Use cases
Satellite
(8GHz 20W TWT)
ECR ion source
（heavy ion radiotherapy）
9 © NEC Corporation 2015 NEC Group Internal Use Only9 © NEC Network and Sensor System, Ltd. 2016
Electron gun
Generating electron
beam
Collector
Collecting spent
electron beam
RF Input / Output
（Waveguide）
Periodic permanent
magnet(PPM)
Focusing electron beam
Slow Wave circuit
Amplified by interaction
between RF and electron beam
RF
RF(Amplified)
Basic structure of TWT
RF window
Maintained in vacuum
and RF transmission
Ex)864 x 432µm
Ex)653 x 95µm
Helix
（Millimeter wave band）
Folded Waveguide
(THz wave band)
Slow Wave Circuit
TWT for wireless communicationsand power modules
11 © NEC Corporation 2015 NEC Group Internal Use Only11 © NEC Network and Sensor System, Ltd. 2016
30
32
34
36
38
40
86 88 90 92 94
15
20
25
30
35
40
-5 0 5 10 15 20 25 30 35
f=90GHz
（Outline dimension：7×7×30cm）
W-band 75-111GHz 5W TWT
（Folded waveguide slow wave circuit）
R
F
O
u
t
p
u
t
[
d
B
m
]
Frequency [GHz]
RF Input [dBm]
86 88 90 92 94
-5 0 5 10 15 20 25 30 35
30
32
34
36
38
40
R
F
O
u
t
p
u
t
[
d
B
m
]
15
20
25
30
35
40
12 © NEC Corporation 2015 NEC Group Internal Use Only12 © NEC Network and Sensor System, Ltd. 2016
MIC R&D program on key technology in THz band
-300GHz-band amplifier technology(2014-2018)
Transmission Equipment
Receiver
ANT300GHz
Receiving Equipment
（Anechoic camber）
� Develop a 300 GHz TWT by
using MEMS technology and
FWG slow wave structure
Wireless communication system for
demonstration research
� Prototype of 300GHz power module
ANT
Power: 1W class
Bandwidth: several GHz
Key device subjects
300GHz band
signal generator
(1) Establish over 1 Watt amplifier technology in 300GHz band(20dB gain)
(2) Realize small size portable amplifier (A4)
(3) Demonstrate several Gbit class wireless transmission(20 to 40 Gbps)
FWG made by X-ray LIGA
Beam stick tube
13 © NEC Corporation 2015 NEC Group Internal Use Only13 © NEC Network and Sensor System, Ltd. 2016
0.3THz-band power module
H
2
O:183GHz
H
2
O:325GHz
O
2
:118GHz
Target
AttenuationAttenuation
O
2
:60GHz
[Expected use case]
Between buildings
Disaster prevention
Sports Events
P-to-P
Frequency 280 to 300GHz
Power 1W
Gain 20dB
Consumption 100W
FY2014 FY2015 FY2016 FY2017
Design **********
Beam test tube *******
TWT prototype
*************
Power module
Prototype
***********
Transmission
demonstration
****
Other applications
15 © NEC Corporation 2015 NEC Group Internal Use Only15 © NEC Network and Sensor System, Ltd. 2016
W-band TWT
Anttena
DUT
W-band imaging
Transimitter
(SSA)
Sensor Array
0.05 to 0.7 THz
64×64, 3 mm pitch
Sub-THz
imaging camera
Replacement
Ceramics
Envelope
Captured image
16 © NEC Corporation 2015 NEC Group Internal Use Only16 © NEC Network and Sensor System, Ltd. 2016
▌Our power modules are expected to extend FWA transmission distance in THz band.
▌Our next issues are:- Development of compact outdoor units
- Further improvement of efficiency, linearity, bandwidth.
▌Developmental utilization of power module technology can have a positive impact on the 5G technology.
Future work
