Present and Future of Terahertz Communications

Transcription

1 TeraHertz: New opportunities for industry TeraHertz: New opportunities for industry February 11, 2013 Present and Future of Terahertz Communications Tadao Nagatsuma Osaka University 1 My First THz J. Appl. Phys. 54 (6), pp (1983). 2

2 Flux Flow Oscillator (FFO) f = Vdc/ GHz/mV (100GHz~700GHz) AC current Load Superconductor Quantized flux V dc I dc Applied magnetic field Insulator Superconductor 3 FFO Integrated MMW/THz Receivers Integrated superconducting receiver for atmosphere monitoring at GHz (TELIS project: TErahertz and submm LImb Sounder) FFO (Local oscillator) 400 x 8~16 m 2 Antenna and mixer (0.8 m 2 ) LO IF RF ISEC 2007 Integrated Receivers for Space by V. Koshelets 4

3 Outline Background and motivation needs for high speed wireless why THz? who pays for THz wireless? Enabling Technologies photonics vs. electronics (reviewing 120GHz band wireless) Photonics base approach direct detection coherent detection Electronics based approach Future issues Summary 5 Outline Background and motivation needs for high speed wireless why THz? who pays for THz wireless? Enabling Technologies photonics vs. electronics Photonics base approach direct detection coherent detection Electronics based approach Future issues Summary 6

4 Trends in Wired Line Bit Rate (Gbit/s) FastE GbE BPON 10GbE Ethernet GEPON 100GbE 10GEPON PON (Passive Optical Network) ~10 times / 5 years Year 7 Trends in Wireless Bit Rate (Gbit/s) Fixed Wireless Access Field Pickup Unit Wireless Backhaul 60 GHz b (WiMAX Fixed) g 120 GHz (5 km) e (WiMAX Mobile) c n 60 GHz? Wireless PAN/LAN? Year 8

5 Approaches to Enhancing Speed 1) Improvement of the spectral efficiency with use of multi value modulation or MIMO (multiple input multiple output) at microwave and millimeter wave frequencies such as 60 GHz/90 GHz 2) Free space optical link possibly with WDM technologies, which have already been established in the fiber optic communications technologies 3) Use of terahertz carrier frequency with simple modulation format like ASK (amplitude shift keying), PSK (phase shift keying), and FSK (frequency shift keying) 9 Developing Higher Carriers Carrier Frequency 1 THz 1 GHz 1 MHz Marconi Radio comms Satellite comms 60 GHz LAN LMDS WPAN THz LMDS:Local Multipoint Distribution Service T. S. Bird, Keynote talk at Asia Pacific Microwave Conference 2011, Melbourne, Australia, December

6 Different Way of Radio Use Increasing power, complexity and cost Shannon theory R (bit/s) = B (Hz) log 2 (1 + S/N) VS. Energy efficient, cost effective, and. Microwaves Frequency = Space THz waves 11 Carrier Frequency vs. Data Rate 100 Data Rate (Gbit/s) 10 1 Wireless LAN Wireless HD 3.8Gbit/s (BW:7GHz) 120GHz wireless 10Gbit/s (BW:17GHz) 300GHz wireless 24Gbit/s Gbit/s Bluetooth Gbit/s Transfer jet (SONY etc.) 0.56Gbit/s Carrier Frequency (GHz) 275GHz Unallocated Region

7 Free Space Loss (1) = 4 r 2 = 4 fr c 2 Loss increases in proportion to square of distance, r, and frequency, f. r A e Point source Loss 4 r 2 /A e A e : Antenna aperture = 2 Ga/4 G a : Antenna gain The above formula is obtained when Ga = 1 (0 dbi). 13 Free Space Loss (2) P r (Rx power)= P t (Tx power) + G t (Tx antenna gain) + G r (Rx antenna gain) - 20 log (4 rf/c) Free-space loss In case of point-to-point link, free-space loss can be compensated with antenna gain, which increases with square of frequency. Example Free-space loss = 134 db for 1 km at 120 GHz ( = 2.5 mm), And it becomes 34 db with 50-dBi antennas for Tx & Rx. 14

8 Friis Formula A et Transmitter r A er Receiver P r = P t (A et A er ) / (rλ) 2 f 2 A et A er P r P t r λ : Effective area of Tx antenna : Effective area of Rx antenna : Transmitted power : Received power : Link distance : Wavelength Assuming the same antenna size, the received power increases with frequency, resulting in lower transmitted power required. 15 Case Study: 60GHz vs. 400GHz Loss due to atmospheric/rain(25mm/h)/fog Transmitted power GHz 27dB 100mW 400GHz 26dB 4 mw Antenna Aperture: 10cmx10cm Received Power (W) GHz 400GHz Link Distance (km) C. M. Mann, in Terahertz sources and systems, Kluwer, 2001, p

9 Attenuation by Air/Rain/Fog 1000 Attenuation (db/km) GHz Dry air Heavy Rain (25 mm/h) Fog (0.1g/m 3 ) Visibility 50 m Visible Light G 100 G 1 T 10 THz 100 T 1000 T Frequency (Hz) 17 Atmospheric Attenuation: Mid. Distance 10 7 Attenuation (db/km) dB/1km 10dB/10km Frequency (GHz) 18

10 Impact of Attenuation by Rain 1 km 1 km Fair condition Rain atten.: 10dB/km Rain atten.: 20dB/km Rain atten.: 30dB/km (=60dB/2km) 100 W 25 W (inversely proportional to square of distance ) 10 W 250 nw 3 orders 6 orders 1 W 2.5 nw 100 nw 25 pw 19 Atmospheric Attenuation: Short Distance 10 6 Attenuation (db/km) dB/10m Future applications Frequency (GHz) 20

11 60 GHz vs. 300 GHz 60GHz band LSI for Baseband Signals Array Antenna 300GHz band Reduction of size: 1/5 (area: 1/25) 25mm 2~5mm Possible to use for consumer devices market opportunity 21 Usage and Requirements 22

12 Example of Beam Steering Techniques K. Sengupta and A. Hajimiri (Caltech), ISSCC 2012 Radiator Core Central VCO Divider Phase shifter 45 nm CMOS 4x4 array 2.7mm x 2.7mm BW: GHz Beam angle: 80 degree Output power: 190 W 23 Who pays for THz Com.?? 1) Broadcasting uncompressed HD x N:1.5 Gbit/s x N uncompressed UHD (SHV): 24 Gbit/s, 42, 72 uncompressed 3D w/ HD or UHD >100 Gbit/s 2) Medical more reality in color and increased resolution for diagnosis huge image data handled at real time for surgery wireless data transfer required in surgery rooms no latency for remote medicine 3) General consumer?? cheaper and smaller 24

13 Expected Applications Reduction of Cost & Energy by Transportation Education & Work 4K TV Medical & Health Cloud Server Conference Site Office 8K TV (12Gbps) School Hospital E books HD Image Medical Sensor Super High Vision(>24Gbps) Life & Environment HD/SHD Relay Points Optical Network Home 4K TV Medical Data Life support Robot Instantaneous Data Transfer Event Site Optical Fiber TV Station/ Network Center Remote Office Health Care Shielded THz Communication 25 Big Wall Displays Change Our Life Hospital Conference site Office 8K TV 3D TV UHD TV Gbit/s 8K TV (>12 Gbit/s) 8K TV School Big wall-displays provide highly realistic-sensation remote communications, and a wireless will be truly user s demand. 26

14 Smart Phone with Wall Displays Courtesy of David Britz, AT&T 27 Big Data: from Store to Circulation 100Gbit/s (12.5GBite/s) proximity link Download Cloud Server Upload Cloud SSD memory SD memory* From Tera-Bite to Peta-Bite We will carry only smart phone with huge memory, when instantaneous wireless transfer of big data becomes possible 28

15 Outline Background and motivation needs for high speed wireless why THz? who pays for THz wireless? Enabling Technologies photonics vs. electronics (reviewing 120GHz band wireless) Photonics base approach direct detection coherent detection Electronics based approach Future issues Summary 29 Electronics based Tx Enabling Technologies: Tx Electrical RF signal generator DATA signal Electrical modulator Antenna Post amplifier Gunn diode + multiplier Oscillator IC, RTD, etc. Diode mixer Amplifier IC Photonics (O/E) based Tx Optical RF signal generator Infrared lasers, etc. DATA signal Optical amplifier Optical modulator EOM EAM EDFA SOA DATA signal O/E converter Photodiode Photoconductor Amplifier IC 30

16 Enabling Technologies: Rx Direct detection Antenna Pre amplifier Electrical demodulator DATA signal Amplifier IC Heterodyne detection Antenna Pre amplifier Amplifier IC Diode detector LO signal source Electrical demodulator Diode mixer Baseband IC Gunn diode + multiplier Photonics based, etc. IF/baseband IC DATA signal 31 Carrier Frequency 120 GHz 120 GHz 200 GHz 220 GHz 250 GHz Recent Developments(1) Technology Tx Rx MMIC(InP) MMIC(GaAs) MMIC(InP) (direct det.) MMIC(InP) (direct det.) Disc. comp. (heterodyne det.) Disc. comp. (heterodyne det.) MMIC(GaAs) Disc. comp. (direct det.) Max. Bit rate (Error free) 10 Gbit/s 20 Gbit/s (with pol.mux) 1 Gbit/s ~15 Gbit/s 8 Gbit/s Affiliation NTT NTT MMIC(CMOS) 120 GHz MMIC(CMOS) (direct det.) 9Gbit/s Hiroshima U. 146 GHz 1 Gbit/s Photonicsbased Photonicsbased Photonicsbased Photonicsbased UCL III-V Lab UC3M IEMN Fraunhofer IAF NTT Osaka-U 32

17 Recent Developments(2) Carrier Frequency 300~400GHz 300 GHz Technology Tx Rx Photonicsbased Frequency multiplier Frequency multiplier Disc. comp. (direct det.) Disc. comp. (heterodyne det.) Disc. comp. (heterodyne det.) Max. Bit rate (Error free) 24 Gbit/s ~100 Mbit/s 300 GHz ~1.5 Gbit/s Affiliation Osaka-U NTT TU Braunschweig ETRI 300 GHz Resonanttunneling diode Resonanttunneling diode 2.5 Gbit/s Rohm Osaka-U 542 GHz Resonanttunneling diode Disc. comp. (direct det.) 1~2 Gbit/s Tokyo Inst. Tech 625 GHz Frequency multiplier Disc. comp. (direct det.) 2.5 Gbit/s NJ IT Bell Lab Gbit/s Wireless Reported, But NOT error free result; use of FEC was assumed. BER was estimated by off line signal processing. 2E 3 Multi level modulation (16QAM) and pol. MUX using W band (75GHz 110GHz) X. Pang et al., OPTICS EXPRESS, Vol. 19, No. 25, 24945(2011). 34

18 Pursuing Error Free Bit Error Rate (BER) = number of errors / total number of bits sent Bit Error Rate 1E-2 1E-4 1E-6 1E-8 1E-10 1E-12 1E-14 Tx/Rx Power??? 2E 3 FEC(Forward Error Correction) limit 1E 11 Error free (practical) 35 BER Movie

19 120 G: Hardware Evolution in 10 years Photonics based Transmitter Transmitter 2004/7 Transmitter Core 2005/8 Photonic MMW Generator Receiver Data Modulator Electronics based Transmitter Transmitter 2007/1 Transmitter Output power: 10 mw, ~2 km Power consumption: 600W 2008/5 Controller Volume: 1/6 Weight: 1/2 Battery operation Output power: 10 mw, 2.2 km Power consumption: 60 W Easy set-up system Mobility, Portability 37 Initiated by Photonics Microwave Photonics 2000 Optical Fiber Slot Antenna (774 x 95 mm 2 ) PD Chip Optical Signal Antenna Si-Lens 1 mm Si Platform MMW Signal 38

20 Powered by MMICs Transistors and amplifiers change the world Transmitter (photonics based) MSL Amplifier Photodiode Output Optical Input Transmitter MMIC Receiver MMIC 39 Electronic Devices: InP HEMT 0.1- m-gate InAlAs/InGaAs HEMT g m = 1.2 S/mm, f t = 170 GHz, f max = 350 GHz MIM capacitor, double-layer interconnection process with BCB BCB SiN/SiO m Fully matured production level technology (NTT Electronics) 40

21 120 GHz band System with Photonic Tx IN Baseband amplifier Data signal (10 Gbit/s) 125 GHz MMW signal Optical modulator 125 GHz Optical signal PD with amplifier MMIC Rx Baseband amplifier Optical MMW signal generator Optical signal Electrical signal Data signal (10 Gbit/s) OUT A. Hirata et al., IEEE Trans. Microwave Theory Tech., vol. 54, pp , GHz Band Transmitter Antenna (45-cm diameter) PD with amplifier Optical signal generator Optical modulator and control board A. Hirata et al., IEEE Trans. Microwave Theory Tech., vol. 54, pp ,

22 Setup for Field Test digital Fiber:50 m Receiver Lab Air transmission:250 m Fiber:400 m analog Transmitter A. Hirata et al., IEEE J. Lightwave Tech., vol. 26, no. 15, pp , Received power (dbm) Transmission Characteristics Receiver power 11:00 12:00 13:00 14:00 15:00 16:00 17:00 Time Total number of bit errors BER 1 st day 3 1X nd day 5 2X rd day 13 5X10-14 Fluctuations in received power: < 1 db for 6 hours BER of wireless link: < 1X10-13 Bit error rate (BER) Meets OC-192 and 10GbE standards A. Hirata et al., IEEE J. Lightwave Tech., vol. 26, No. 15, pp ,

23 120 GHz band Transmitter with Electronics LO signal IN Power amp. module Power amp. MMIC 120 GHz with WR-8 waveguide (>40 mw) to antenna DATA IN LO: GHz Transmitter module Multiplier(x4) MMIC LO:62.5GHz Transmitter MMIC Battery operated DATA IN Optical data (10-Gbit/s) XFP module (O/E) NTT Technical Journal, Vol. 19, No. 5, pp , 2007 (in Japanese). 45 Advanced All Electronics System Controller Tx Frontend Camera cable ( ~1km ) Transmitter head Cassegrain anntena Bayonet mechanism 100~240 V AC HD-SDI signal 10-Gbit/s optical signal Controller AC/DC Controller E/O 10-Gbit/s electrical signal Power supply Controller O/E XFP NTT Technical Review, vol. 7, no. 3, Mar GHz PA module Tx module Waveguide (2 mm 1 mm) 46

24 120 G: Now 10 Gbit/s, >5 km, InP HEMT MMIC with FEC Bidirectional with polarization multiplex Beijing Olympic 10 2 Data rate: Gbit/s Bit Error Rate Minimum received power: 38 dbm Received Power (dbm) 48

25 Results of 120 Olympic View from BMC Experimental Setup 1 km Received power (dbm) Fluctuations < 2dB Time (hr) Received power on August 8 (Opening day of Olympics) Date 8/ Time of day TV programs with 120-GHz system 49 Indoor 4 K Digital TV Transmission (<10 m) Tx Rx 4-K Display Link Distance < 10 m Tx Rx Small Antenna 30 mm 50

26 Teleconference with 10 G Wired & Wireless NICT (Tokyo) Media Server cloud NTT Musashino JGN 2 Plus (10G Ethernet system) 3D and 4 K data NICT (Kyoto) KDDI Building NTT Com Building Medical Dr. A 120 GHz link (10mW) 150 m (thr. Windows) Bi dorectional Medical Dr. B 51 Outline Background and motivation needs for high speed wireless why THz? who pays for THz wireless? Enabling Technologies photonics vs. electronics Photonics base approach direct detection coherent detection Electronics based approach Future issues Summary 52

27 Photonics based Tx & Direct Detection Seamless between fiber optic and wireless Data(OOK) Fiber-optic link 1 Optical Modulator Base band Photodiode Data 2 Photo mixing RF Photodiode Wireless link Unlocked f RF = c 1 2 RF Receiver Data 53 Photo mixing Generating THz Signals f 1 f 2 frequency f 2 - f 1 frequency Tunable laser 1 Tunable laser 2 Photo mixing Photodiode 54

28 300 GHz Band Experiment Tx Photodiode THz wave f RF freq. Rx Schottkybarrier diode Horn anttena Optical amp. Dielectric lens Preamp. Baseband Freq. Optical modulator Optical freq. Pulse pattern generator Baseband freq. Limit amp. f Optical freq. Wavelength tunable laser Wavelength tunable laser Oscilloscope Error detector 55 Photo of Setup Dielectric Lens Transmitter Receiver 56

29 Fast Photodiode Technology diffusion block layer p-contact layer p-doped absorption layer un-doped collection layer (C.B.) un-doped absorption layer n-contact layer (V.B.) Stub UTC-PD DC bias C RF out 100 µm 57 Output Power at GHz Detected Power ( W) GHz 90 Gbit/s w/ ASK ma ma Frequency (GHz) 58

30 Increasing Output Power Chip Structure Output Combiner PD PD Output power (dbm) ma per PD Photocurrent per PD (ma) 59 Photo of Transmitter PD Module Dielectric Lens Optical Fiber Horn Antenna 60

31 New Antenna Technology Photodiode 300 GHz 50 mm 100 mm 42 mm Collaboration with J. Hirokawa and M. Ando (Tokyo Inst. Tech) Photodiode 61 Low profile Array Antenna Plate-laminated waveguide slot array antenna Radiating Slot Cavity Coupling Slot Feeding Network 16 x 16 (256), 32 dbi 11.2 mm 11.2 mm 0.6 mm 62

32 Receiver Configuration Bandwidth of baseband signals~ 20 GHz Antenna Baseband signal 120 m Schottky barrier diode Baseband signal Receiver chip Receiver module Silicon lens E-4 24 Gbit/s Error Free 12.5 Gbit/s 24 Gbit/s Bit Error Rate 1E-6 1E-8 1E Gb/s 1E W 50 W 1E Photocurrent (ma) 24 Gb/s Minimum data rate for UHD 64

33 Eye Diagrams up to 30 Gbit/s 20 Gbps 26 Gbps PD current 10 ma 20 ps 20 ps 22 Gbps 28 Gbps 20 ps 20 ps 24 Gbps 30 Gbps BER ~ Use of Ultra Broadband (a) Ultra-broadband channel (b) Multiple giga-bit channels Carrier Carrier Power Power >40 GHz (24 Gbit/s) >70 GHz (43 Gbit/s) UHD OC-768 HDTV 2.5 GHz (1.5 Gbit/s) Frequency 66

34 280 to 400 GHz Experiments 280 GHz 300 GHz 400 GHz (a) 320 GHz 340 GHz (b) (g) 500 ps 1.0 Gbit/s (c) 360 GHz 380 GHz (d) Usable bandwidth: 120 GHz 48 ch. HDTV (e) (f) to 720 GHz Experiments 1.6 Gbit/s 450 GHz (a) 600 GHz (d) 500 GHz (b) 650 GHz (e) 550 GHz (c) 720 GHz Usable bandwidth: 270 GHz 108 ch. HDTV (f) 68

35 Multi band Receivers 1.5 Gbps Experiments 69 Future Strategy 100 Wired (Ethernet): 100 Gbps 100 Gbps Data Rate [Gbps] ASK Modulation Max 22 Gbps Multi value mod. (e.g., QPSK) Now Max 30 Gbps 40 Gbps 10 Max 11.4 Gbps Max 16 Gbps x 70

36 Outline Background and motivation needs for high speed wireless why THz? who pays for THz wireless? Enabling Technologies photonics vs. electronics Photonics base approach direct detection coherent detection Electronics based approach Future issues Summary 71 Towards Coherent Detection Transmitter IM: Intensity Modulator Receiver Opt. Carrier 1 Opt. Carrie 2 Data IM PD RF LO Local Oscillator IF Data Stability of RF signal is dependent on those of optical carriers Frequency difference in optical carriers should be stabilized 72

37 Example of Recent Studies GHz 10Gbit/s PPG Laser MZM Modulator QPSK Modulator EDFA EDFA Freq. Quadrupler AWG Filter I Carrier Recovery IF RF Horn Photodiode Q IQ Separa -tion LO (75 GHz) Optical Coherent Receiver Kanno et al., IEICE Electronics Express, vol. 8, no. 8, pp (2011). 73 Use of Optical Frequency Comb Transmitter Receiver 1 2 Optical Filter IM PD RF IF Data Optical Frequency Comb Generator (OFCG) Data Wavelength LO Local Oscillator 1.5 GHz Frequency is stabilized Unstable transmission 74

38 Origin of Instability Optical Carrier RF Signal From OFCG Optical Filter 1/f 1 PD Coupler 1/f 2 Phase instability between optical carriers Jitter of photonically generated RF signal 75 Countermeasure x ref = cos( t) Reference Arm PS:Phase shifter x carrier = cos{( t) + (t)} PS Coupler Feedback Circuit Slow PD cos{ (t)} Locking to the reference optical signal by feedback circuitry 76

39 Stabilized Transmission 25 GHz OFCG Optical Filter PS 100 GHz PS IM Data UTC PD 1.5 Gbps RF Feedback Signal to Each PS GHz Transmitter Low Speed PD Optimized FB Error free transmission 200 ps/div. 77 BER Characteristics Theoretical BER Coherent Detection Direct Detection Transmitter Power (dbm) 78

40 Outline Background and motivation needs for high speed wireless why THz? who pays for THz wireless? Enabling Technologies photonics vs. electronics Photonics base approach direct detection coherent detection Electronics based approach Future issues Summary 79 Output Power by Electronics High power MMW amplifier + Frequency multiplier 20~40 μw (w/ 1.7~1.9 THz Transistor based oscillator IC GHz with InP DHBT, 780 μw at 290 GHz, 160 μw at 480 GHz with CMOS Resonant tunneling diode (RTD) oscillator GHz, GHz (2 arrays), 10 μw@ 1.3 THz 80

41 Comparison Output Power (dbm) SiGe HBT CMOS CMOS InP HEMT InP HBT 10 W CMOS RTD Frequency (GHz) 81 CMOS based Generator 45nm CMOS: ~1mW 180~190GHz M. Uzunkol et al., Tech. Dig. IMS 2013, June

42 Progress in Resonant Tunneling Diode 2 element array 610 (S. Suzuki et al., IEEE J. Select. QE, 2012.) Single ~10 THz (H. Kanaya et al., IPRM 2012) 83 Antenna integrated RTD Tapered Slot Antenna RTD Chip RTD Electrode n+ingaas 8nm n+ingaas 15nm n-ingaas 25nm un-ingaas 20nm un-alas 1.1nm un-ingaas 4.5nm un-alas 1.1nm un-ingaas 2nm n-ingaas 25nm InP Substrate Tunnel Barrier Quantum Well Tunnel Barrier Electrode n+ingaas 400nm 84

43 Principle of RTD 1 電極 Au/Pd/Ti Barrier n+ingaas n-ingaas un-ingaas un-alas un-ingaas un-alas un-ingaas n-ingaas Electron Well n+ingaas Resonant level Layer Structure Tunnel Barrier Quantum Well Tunnel Barrier 半絶縁 InP sub Barrier 電極 Au/Pd/Ti 2 V DC Current Thin layers (~1 nm) 1 Energy Band I-V Characteristics 2 DC Voltage 3 V 3 Common Diode 85 Operation Points DC Current (ma) 10 0 電流 -10 Operation point for transmitter A 電圧 (V) Operation point for receiver DC Voltage (V) B 86

44 Transmitter Operation Non Oscillation I Oscillation Output Input Data Signal V Negative Differential Resistance (NDR) Region 87 Receiver Operation I Strong non-linear region! Output Input V Square law detection I( V) 2 a 4 d 2 dv I 2 V V 0 88

45 Transmitter RTD Transceiver Receiver RTD DC Bias DC Bias Blocking Capacitor Variable Attenuator Preamp. Limit amp. Pulse Pattern Generator To oscilloscope and error detector 89 1 BER and Eye Diagram 1.5 Gbit/s 10-2 BER Gbit/s DC bias voltage (V) 250 ps 90

46 120GHz/140GHz Rx IC (Hiroshima U) Data rate: 3~4 Gb/s, Distance: 30~40 cm w/ 25 dbi horn SSCS Distinguish Lecture (Prof. Fujishima) 92

47 120 GHz Tx IC (KULeuven) Noël Deferm, Patrick Reynaert, ISSCC2011, nm LP CMOS Technology Supply voltage: 1V Power consumption: 200 mw Data rate: 10 Gb/s(QPSK), 6 Gbit/s(8QAM) GHz band System with MMICs Fraunhofer IAF I. Kallfass et al., All active MMIC based wireless communication at 220 GHz, IEEE Trans. Terahertz Science and Technology, Vol. 1, 577(2011). 94

48 300 GHz Band Wireless Link (TUBraunschweig) GHz x GHz signal generator 125 dbc/hz (20 khz offset) amplifier and 2 tripler broadcast tester 1000 ± 4 MHz 32 µw a) ± 1 GHz 3.2 µw GHz x GHz signal generator 105 dbc/hz (20 khz offset) amplifier and 2 tripler LNA 1360 ± 4 MHz G = 32 db F = 3.5 db b) ± 1 GHz LCD DVB-S2 receiver TV analyser C. Jastrow, S. Priebe, B. Spitschan, J. Hartmann, M. Jacob, T. Kürner, T. Schrader and T. Kleine Ostmann, Wireless digital data transmission at 300 GHz, Electron. Lett. 46, (2010) GHz Band Link (ETRI/Korea) ETRI Journal, Volume 33, Number 6, December

49 600 GHz Band Link (Bell Lab/NJIT) 1mW doc.: IEEE thz 97 Outline Background and motivation needs for high speed wireless why THz? who pays for THz wireless? Enabling Technologies photonics vs. electronics Photonics base approach direct detection coherent detection Electronics based approach Future issues Summary 98

50 Towards THz ICs WE ARE HERE 3 rd Phase: integration Smaller & cheaper for mass-production/use 2 nd Phase: transistor & passives More performance & functional Active: THz amplifiers and oscillators Passive: THz antennas, filters, absorbers 1 st Phase: diode Technology demonstration Investigate advantages, disadvantages, usefulness of THz Modeling THz propagation, reflection 99 Transmission Lines for THz ICs Loss Size Cost Hollow Waveguide Metallic PhC Waveguide 100

51 Comparison (Theoretical) Propagation Loss [db/cm] THz THz PhC Waveguide Si Resistivity [Ωcm] Planar Metallic Hollow Waveguide 101 Fabrication on Si 300 μm 200 μm 300 μm 102

52 Preliminary Experiments Transmission [db] PhC Waveguide PhC Frequency [THz] 103 Roadmap Professional use (Broadcast, medical) LAN, Interconnections, etc (bit/s) Near-field wireless 100G 40G 10G 1G Photonicsbased Electronicsbased (GaAs/InP) Electronicsbased (Si/Ge) Key milestone

53 Timeline towards Freq. Allocations ITU R International Telecomm. Union Radiocomm. Sector WRC World Radiocomm. Conference RA RA RA WRC2012 WRC2015 WRC2018 IEEE (IEEE820.11) THz Interest Gr. Since 2008 SG 1 SG 2 TG 1 TG 2 SG 3 TG IEEE IEEE 802 LAN/MAN Standards Committee Higher Layer LAN Protocols Working Group Wireless Local Area Network Working Group Wireless Personal Area Network Working Group Wireless Regional Area Networks TG4j Medical Body Area Networks TG4k Low Energy Critical Infrastructure Monitoring TG4m TV White Space TG8 Peer Aware Communications TG9 Key Management Protocol 106

54 On going Discussions (1) doc.: IEEE thz

55 On going Discussions (2) doc.: IEEE thz 109 Study on Interference Effects Operational heights of Earth exploration satellites: km 60dBi 110

56 Summary Use of high frequency carriers such as millimeter waves and terahertz waves is effective to increase the bit rate. Photonics based signal generation and modulation technique enables seamless connections between wired and wireless networks. 300 GHz band wireless link with direct detection scheme has reached error free30gbit/s. 600 GHzbandensures higher. To increase the bit rate and receiver sensitivity, coherent detection scheme has been examined; a proof of concept experiment has been demonstrated at 100 GHzband. For low cost and/or consumer applications, electronicsbased approach is essential, and use of RTDs has been demonstrated at 300 GHz band, in addition to Si based Tx/Rx. 111