Optical micro-system switches in future telecom payloads

Transcription

1 Template reference : S-EN Optical micro-system switches in future telecom payloads by M. Sotom - CNES Workshop MOEMS in Space, Toulouse Outline Page 2 Introduction Future Telecom payloads Optical technologies & optical switching MEMS-based optical switches Microwave photonic repeater : a MOEMS-based payload sub-system Conclusions 1

2 Telecom satellites & payloads Page 3 Satellite Systems (SS) to complement ground telecom segment providing global reach (world-wide direct broadcasting) providing wide access to the backbone establishing short cuts between backbone edge-sites substituting ground segment (sparsely populated areas, developing countries, deployment phase) Evolution of conventional broadcast SS and fixed SS, driven by Multimedia / IP interactivity in broadcast system (need for return link) FSS extended to bidirectional links Gateways/users & users/users Telecom satellites & payloads Page 4 Future broadband telecom missions GEO based satellite migration to Ka-band (30 GHz up-link / 20 GHz down-link) broader bandwidth high-directivity antenna multi-spot beam coverage frequency reuse antenna flexibility flexible beam-to-beam connectivity versatile and future-proof solutions (15-year lifetime) 2

3 3 Telecom satellites & payloads Future broadband telecom payloads flexible complex payloads : coverage, connectivity, frequency plan, bandwidth allocation 100 s of RF channels (10 s of MHz) over 10 s of antenna beams critical requirements in terms of mass, volume & power consumption future-proof solutions = transparent payloads (analogue or digital) Page 5 Analogue payload Digital payload LNA Analogue Digital Processor Signal 30/IF DoCon IF/20 UpCon HPA LNA 30/IF DoCon ADC Processor DAC IF/20 UpCon HPA (filters & switches) Reference / Master LO / Synt. LO Reference / Master LO / Synt. LO Optical technologies Page 6 Potentials of optical and microwave photonic technologies low mass and small size broadband bandwidth RF isolation, suppression of EMC/EMI issues transparency to RF frequency multiplexing (WDM) parallelism (3-D processing) Optical switching RF signal routing LO delivery redundancy switching Hi-thruput digital interconnects SIGNAL HANDLING FUNCTION LO generation Reference / LO distribution Signal distribution & switching Frequency mixing Amplitude / phase control Fast sampling APPLICATION Analogue repeater Digital processor Antenna

4 Optical switching technologies Thermo-optic switch integration loss, limited isolation, power consumption Electro-optic switch integration, fast switching high driving voltage SOA-based switch (Semi-conductor optical amplifier ) fast switching, high isolation noise and non-linearities Optical phased-array switch fast switching, medium scale limited isolation, compatibility w/ SMF? MOEMS switch low loss, high isolation, low consumption, up to large scale slow switching, durability? preferred optical switching technology Page 7 MOEMS switch architectures Page 8 Elementary 1x2 and 2x2 switches SERCALO, DICON, NORTHROP GRUMMAN Hybrid assemblies of discrete 1x2, 1xN switches any connectivity matrices as Spanke network SERCALO, DICON (up to 24x24) Integrated 2D crossbar switches planar matrices with digital control complexity grows as N 2 single-sided or double-sided AT&T, OMM, SERCALO 4

5 5 MOEMS switch architectures Page 9 Analogue, free-space MOEMS switches linear mirror arrays, with analogue 2D steering mirror matrices with analogue 3D steering complexity grows as 2.N folded, unfolded architectures LUCENT, Glimmerglass, NTT, FUJITSU Large MOEMS switch architectures Page 10 Single-stage, 2D-MOEMS switch substantial loss uniformity limited to medium scales (< 16x16) Multi-stage switch networks (Xbar, Clos, tree-like) large # of modules (Xbar & tree-like grow as N 2 ) high loss and loss uniformity (Xbar) high loss (Clos, Benes, tree-like) Single-stage, 3D-MOEMS switch best optical performance (loss and uniformity) best trade-off of integration & complexity of optical HW & control scalable to high port counts (10 s x 10 s), partitionable into smaller matrices, configurable as asymmetric matrix

6 6 Flexible MW photonic repeater Page 11 Payload application & concept broadband backbone connectivity mission GEO-based satellite Ka-band (30/20 GHz) or higher broad bandwidth (~ 1 GHz) multi-spot beam coverage (10 s of beams ) flexible beam-to beam cross-connectivity versatile solutions (15-year lifetime) Flexible analogue transparent repeater Flexible MW photonic repeater Page 12 Generic architectural concept optical distribution of centralised LO s optical frequency down-conversion optical cross-connection of µ-wave channels Rx section Merits flexible beam-to-beam connectivity broadband, frequency-independent design scalable to large sizes low mass & volume, power consumption Tx section Rx antennas Tx antennas LNA EOM Optical X-Connect HPA Optical LO s LO LO LNA : low-noise amplifier EOM : electro-optical mixer HPA : high-power amplifier

7 7 MW photonic repeater demo Page 13 Breadboard system demonstrator sub-populated, yet representative of full scale system Ka-band (30 to 4 GHz) Microwave photonic LO source Photonic frequency mixer 4x4 MOEMS-based optical cross-connect Microwave optoelectronic receivers MW photonic repeater demo Page 14 Flexible repeater demo channel cross-connection based on 4x4 MOEMS switch high performance switch cascaded discrete 2x2 switches optical loss < 2 db optical crosstalk < -60 db low-consumption compact OFA 5 4 (commercial) re-configuration under PC control functional over all 16 optical routes Relative RF power (db) Input port Output port

8 8 MW photonic repeater demo Page 15 Repeater RF performance linearity performance (2-tone C/I > 54 dbc) not affected by OXC RF path isolation > 80 db, whatever the OXC route & configuration no increase of phase noise of IF signal, whatever the OXC route & configuration C/I > 54dB X-talk < -80dB Phase noise (dbc/hz) db optical loss 17 db loss with OXC (route 1-1) 17 db loss with OXC (route 1-1 / all inputs conn.) 17 db loss with OXC (route 4-1 / all inputs conn.) with 1-1 OXC route established with 1-1 OXC route released E+0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 1E+7 Offset frequency (Hz) Conclusions Page 16 Photonic and microwave photonic technologies in future telecom payloads for enhancing conventional implementations (mass, density, isolation ) as enabling technologies for advanced subsystem concepts Optical switches are key optical building blocks elementary switches & assemblies of discrete switches for redundancy switching, & selection switching large matrices for cross-connectivity switching MOEMS-based switches are preferred best optical performance (loss, isolation) higher integration low power consumption can grow to large scales Early demos of MOEMS-based microwave photonic sub-systems have confirmed feasibility and proved excellent RF performance

9 9 Acknowledgements Page 17 Part of this work has been supported by ESA under contract n 15695/01 - Optical Handling of Microwave and Digital Signals, also nicknamed as SAT N LIGHT. Part of this work has been supported by ESA under contract n 19531/06 - Large Optical MEMS switch architectures for BB space applications. Special thanks to Mr. Josep PERDIGUES, Technical Officer at ESTEC, and to our Partners in these projects for fruitful cooperation. contact : michel.sotom@thalesaleniaspace.com