Yasuhiro Nakasha

FUJITSU LIMITED

A Compact 300-GHz Receiver

for Wireless Communications of

Tens of Gigabits per Second

Copyright 2016 FUJITSU LIMITED

Compact 300-GHz Receiver

Background

Issues and developed technologies:

Devices (InP HEMTs)

ICs (low-noise amplifier, detector, IF amplifier)

Packaging

Demonstration

Summary

Copyright 2016 FUJITSU LIMITED1

THz Wave

Not allocated above 275 GHz

10-100 GHz bandwidth (BW) usable

100 Gb/s+ possible with simple modem

Large atmospheric attenuation

Copyright 2016 FUJITSU LIMITED

0 20 40 60 80 100 120 200

11ad

Frequency (GHz)

LTE、WiFi, etc

300

FWA, TV, etc E-band AmateurAutomotive

1000

W-band

TV relay

Japanese allocation

m wave mm wave

10 – ~100 Gb/s+~10 Gb/s~ Gb/s

Target

THz wave (>100 GHz)

2

THz Use Cases

Short-range service

Data downloader

Data exchanger

Data center

Fixed wireless service

Copyright 2016 FUJITSU LIMITED

Data downloader

FH

FH

Front haul (FH) for cellular

3

Receiver Challenges for THz Downloader

Compact module with small antenna

- High-fmax device

- Low-noise amplifier (LNA)

- Wide-band detector (DET)

- Low-loss compact packaging

Copyright 2016 FUJITSU LIMITED

BB unit

LNA DET

Receiver (This work)

BB unit

PAModulatorOSC

Transmitter

Data downloader

IF amp.

ANT

4

Low-noise THz Device Technology

75-nm InP HEMT

- Cavity structure

- fT / fmax: 320 GHz / 660 GHz

- NFmin：0.71 dB @94 GHz, 300K

Copyright 2016 FUJITSU LIMITED

Frequency (GHz)

1 100 100010

Ga

in (

dB

)20

40

60

0Vd=1 V, Vg=0.2 V

fT = 320 GHz

fmax = 660 GHz

U

|h21|

Gate

Cavity

500 nm

BCB

DrainSource

T. Takahashi et al., IEEE ED 2012

5

InP-HEMT Low-noise Amplifier (LNA)

Common-gate architecture for high gain and wide BW

NF: 9.8 dB @300 GHz

Copyright 2016 FUJITSU LIMITED

1.8×0.9 mm

IN OUT

6-stage common-gate LNA

-30

-20

-10

0

10

20

30

S11

S22

S21

220 260 300 340

S-p

ara

mete

rs (

dB

)

Frequency (GHz)

> 20 dB, 80 GHz

6

Wide-band Detector

InP HEMT Schottky diode

Wide-band differential IF amplifier

All Integrated on 1 chip

Pdiss: 115 mW

Copyright 2016 FUJITSU LIMITED

2.5×0.8 mm

RF IN IF OUT

Integrated receiver IC

IF amp.

InP Schottky diode

LNA DET

Matching

310300290280270 320

100

60

20

Frequency (GHz)

Sen

sit

ivit

y(k

V/W

)

140

> 50 kV/W, >30 GHz

7

Low-loss Compact Packaging

Expanded flip-chip mounting to THz-band for the first time

- Employing low-loss polyimide substrate

Compact built-in horn antenna: 16 dBi

Cubic capacity: 0.75 cm3

Copyright 2016 FUJITSU LIMITED

Built-in antenna

Polyimide substrate

Module housing

Bump

Via hole

Receiver IC

TH

z w

ave

WG-MSL

ANT

Receiver module

Flip-chip mounted receiver IC

Y. Kawano et al., EuMC 2015

8

Downloader Demo

Collaboration with NTT, NICT, and FUJITSU

Physical rate: 20 Gb/s, effective rate: 16 Gb/s

Copyright 2016 FUJITSU LIMITED

H. Song, H. Hamada et al., IEEE IMS 2016

110cm

Tran

smitter

Receiver

50ps

Downloader server

Transmitter

Hand-held receiver

Downloading scene

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Summary

Compact THz receiver for 20-Gb/s data transmission

- 75-nm InP HEMT fmax: 660 GHz

- 1-chip receiver IC

- Low-loss flip-chip mounting technique

- Cubic volume: 0.75 cm3

Instantaneous downloader demo

- 300 GHz, 20 Gb/s

- Only 2 sec. for 1-DVD data (4GB)

Copyright 2016 FUJITSU LIMITED

This work was jointly established by NTT, NICT, and FUJITSU, and was

supported in part by the research and development of the Ministry of

Internal Affairs and Communication, Japan

10

Copyright 2016 FUJITSU LIMITED11