PhLEXSATPhoto-Digital Channelizer for Flexible High Throughput Satellites
Photonic technologies are key enablers to satisfy the requirements of future Terabit/s communication satellites. The ability of Photonics to handle high data rates and frequencies is critical in this scenario, where current purely RF technologies are limited in SWaP and performance.
However, the use of photonics devices is currently restricted to a few demonstrations in non-critical equipment and with limited degree of integration. PhLEXSAT will increase the maturity level of several key photonic devices and modules to TRL5, designing, fabricating and testing:
- Photonic sampler,
- Ultra-low jitter photonic clock for precise sampling,
- Photonic-assisted ADC and DAC for digital channelizers for Q/V-band operation and
- On-board digital processing firmware.
Miniaturization will be achieved by fabricating and integrating a modulator photonic integrated circuit (PIC) and high-linear photodiode PIC with electronics in the photonic ADC and DAC components.
PhLEXSAT will integrate and demonstrate such building blocks in a test bed proving the suitability of the proposed architecture for Tbps-like, software defined HTS payloads with hundreds of channels with flexible bandwidth allocation up to 1GHz/channel, demonstrating a flexible photo-digital channelizer for high capacity reconfigurable payloads, enabling flexible frequency plans and channelization and dynamic coverage for Ku/Ka/Q/V operation.
PhLEXSAT consortium comprises the multidisciplinary skills needed to achieve its objectives and fully exploit its results, with partners representing the whole value chain, from space-grade hardware developers to communications satellite integrators and operators.
PhLEXSAT builds on the results of the previous FP7 project PHASER and is complementary to developments made by its partners in previous and existing ESA and EC Projects. PhLEXSAT success will contribute to enhance EU competitiveness and non-n-dependence by developing critical technologies for the EU satellite industry.
EU contribution (€)
TOTAL COST (€)
TERM OF COMPLETION:
01st November 2020 to 30th April 2023
CALL FOR PROPOSAL:
The PhLEXSAT consortium brings together a wealth of expertise and resources within the areas of: photonic components and modules, packaging, space grade technologies, and satellite integrators and operators.
The PhLEXSAT consortium represents the whole photonics enabled flexible Terabit-per-second-like digital payload value chain, starting from firmware and components developers, equipment supplier and extending to the satellite integrator towards the satellite operator.
The industrially driven nature of the Consortium, involving three SMEs (DAS, aXenic, AT) in close cooperation with two LE (MDA, EUT) very active in technology transfer and industrial cooperation, grants the achievement of results with high industrial potential
DAS PHOTONICS S.L. (DAS)
Pioneering company in the design, fabrication and IoD of SATCOM photonic payloads.
Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
High-speed InP photodetector manufacturer.
MDA Space and Robotics Limited (MDA)
World leader in communication satellite manufacturing, pioneer in photonic technology for communication satellites.
Photonics packaging and related design house including assembly line. Packaging expert in RF simulation and design, optical coupling etc.
One of the world’s leading and most experienced operators of communications satellites.
The main objective of PhLEXSAT is the development to TRL5 of a photonic digital payload demonstrator. PhLEXSAT team will take the next step in achieving the paradigm of the full-flexible Tbps-class payload by synergically mixing of Q/V bands, photonics and digital on-board processing within a new concept of photo-digital channelizer.
The PhLEXSAT specific objectives are summarized as follows:
|1. Development of 55GHz Mach-Zehnder Interferometer (MZI) PIC based on GaAs travelling-wave electrooptic modulator technology.|
|2. Development of High Linear photodetector (HL-PD) PIC based on InP technology.|
|3. Development of Photonic Sampler with a co-package of MZI PIC and HL-PD PIC.|
|4. Electronics circuitry including bias and clock recovery, broadband TIA, quantizer and DAC.|
|5. Development of a photonic ADC integrating photonic sampler and electronic circuitry.|
|6. Development of a photonic clock with space-grade specifications.|
|7. Development of Receiving Digital Channelizer (RxDC) including post-linearization, channel filter and digital down-conversion.|
|8. Development of the Digital space router interfaces compatible with the existing on-board digital processors.|
|9. Development of Transmitting Digital Multiplexer (TxDM) including digital up-conversion and multiplexing, and pre-emphasis.|
|10.Development of a photonic DAC integrating photonic sampler and electronic circuitry.|
|11.Photonic payload demonstrator at TRL5 integrating photonic clock, photonic ADC and DAC and on-board real-time digital processing firmware (RxDC, router, TxDM). Demonstrator compatible with MDA Onboard processor. Development ready for TRL increase and in-orbit validation in 2 years after the project finalization.|
The Photonic Sampler is the key element of the Photonic ADC and Photonic DAC subsystems, capable of down/up-converting high bandwidth signals without electronic mixing hardware or intermediate frequency stages. It consists of a carrier based on dual PIC: dual modulator and photodiode array.
aXenic has in-depth and unique capability in high-speed Mach Zehnder Interferometer (MZI) modulators using the GaAs/AlGaAs material system. The environmental credentials of the GaAs/AlGaAs III-V semiconductor material system are well known. It has many desirable properties for RF devices which must survive and operate in harsh environments and has remained the material of choice for mm-wave electronics and MMICs.
During the PhLEXSAT project aXenic will design and fabricate a compact, dual MZI PIC with high bandwidth (55+ GHz) for integration into the photonic sampler.
The photodetector PIC will operate as a down-converter for converting the optical signal of the photonic ADC and DAC into the electrical domain. Key features of the photodetector PIC are the monolithically to waveguides integrated photodiodes, providing a high linearity and therefore minimizing distortions of the generated RF-signal.
The Photonic ADC subsystem capable of down-converting and digitize a band pass signal up to V-band. It consists of a multi-carrier package with two RF input interfaces, one optical input for the optical clock, a photonic sampler, two broadband Trans-Impedance Amplifiers (TIA) and quantizers, high-speed output pins for the digital signal output and low-speed I/O ports for telemetry and control. The development includes the design of the electronic circuitry including MZI bias control and clock recovery which is implemented outside the package via the I/O TM/TC ports. Thanks to the functional and environmental tests at component and module level, the Photonic ADC unit will be TRL 5.
The Photonic DAC subsystem capable of converting to analogue and up-converting a band pass signal up to Q-band. It consists of a multi-carrier package with two RF output interfaces, one optical input for the optical clock, a photonic sampler, two electronic DAC, high-speed input pins for the digital signal input and low-speed I/O ports for telemetry and control. The development includes the design of the electronic circuitry including MZI bias control and clock recovery which is implemented outside the package via the I/O TM/TC ports. Thanks to the functional and environmental tests at component and module level, the Photonic DAC unit will be TRL 5.
A mode-locked laser will be developed that will act as a frequency clock in the system to drive the photonic sampler within the Photonic ADC and Photonic DAC. Key features of the Photonic clock are the sub-picosecond pulses together with the rigid mechanical cavity implementation, enabling ultra-low phase noise and timing jitter, which guarantees a very precise sampling of the signals. The Photonic Clock will be based on current DAS developments and consists of photonic components as well as the control electronics. The current design will be adapted to the requirements imposed by the PhLEXSAT scenario. Thanks to the functional and environmental tests at component and module level, the Photonic Clock unit will be TRL 5.
Digital processing firmware
The on-board processor is divided in three major blocks: (1) Receiving Digital Channelizer (RxDC), (2) Space router and (3) Transmitting Digital Multiplexer (TxDM). All the modules of the firmware are running in high-speed FPGAs.
In the RxDC module, the digital signal from the ADC is processed by some post-processing algorithms to compensate the non-linearities of the photonic sampler. Subsequently, a filtering stage separates the different input channels. The filtered channels are digitally down-converted to a common digital IF and are directed to the space router.
The space router is devoted to route any incoming digital channel to a specific output, which can be re-programmed. The output of the Space Router section consists of a parallel set of outputs grouped to specific transmitter, which include Mx channels (being x the output port) and are routed to the TxDM module.
In the TxDM module, all the channels routed to a specific user are digitally up-converted and multiplexed in order to feed the DAC with the already digitally generated IF signal. The digitally generated multiplex is pre-processed before entering the DAC for pre-linearization.
PhLEXSAT website is on air
PhLEXSAT (Photo-Digital Channelizer for Flexible Digital High Throughput Satellites) is a H2020- Satellite Communication technologies -Space project funded by the European Commission
Public deliverables will be linked to the PhLEXSAT results page in CORDIS, where they can be downloaded:
D10.1 Dissemination and Communication Plan including Website (Month 6)
D10.4 Report on Dissemination and Communication activities (Month 30)
M. Chatterjee, C. Palla, E. Fiamanya, S. Legate, A. Castells Cervello, L. Roux, M. Beltran, M. A. Piqueras, P. Runge, N. Cameron, J. Zverina, “Design and Development of PhLEXSAT – A Flexible Photo-Digital Communication Payload for Very High Throughput Satellites,” International Conference on Space Optics (ICSO), Dubrovnik, Croatia, October 3-7, 2022, https://www.spiedigitallibrary.org/icso?SSO=1
M. Chatterjee, C. Palla, E. Fiamanya, A. Castells Cervello, L. Roux, M. A. Piqueras, P. Runge, N. Cameron, J. Zverina, “PhLEXSAT – A novel photo-digital communication payload for very high throughput satellites,” International Astronautical Congress, IAC 2021, Dubai, United Arab Emirates, October 25-29, 2021, paper 64593.
Link to editor page: https://dl.iafastro.directory/event/IAC-2021/paper/64593/
Miguel A. Piqueras, “Recent advances of photonics processing in the satellite market,” 2021 International Topical Meeting on Microwave Photonics (MWP), Virtual Conference from Italy, November 15-17, 2021, Invited paper.
M. Chatterjee, C. Palla, E. Fiamanya, M. Beltran, Miguel A. Piqueras, A. Castells Cervello, L. Roux, P. Runge, J. Zverina, N. Cameron, “PhLEXSAT – A Very High Throughput Photo-Digital Communication Satellite Payload,” 2022 IEEE International Conference on Space Optical Systems and Applications (ICSOS), Virtual Conference from Japan, March 28-31, 2022, pp. 154-157
Funded by the Horizon 2020 Research and Innovation Programme of the European Union