The main objective of this project has been to perform the Definition Phase for the MULTIGS concept. The MULTIGS Project is part of the ARTES Program and will enable the capability to simultaneously track and communicate with multiple satellites in different orbits, in both high gain and low gain applications.
A generic multi-beam ground station concept able to cope with TT&C communications for Navigation Satellite Systems or Radioastronomy applications on substitution of large reflectors has been developed. These type of applications require mostly S-Band (TT&C) or L-Band (VLBI), thus the product is based on a modular concept in order to scale the product to other services and applications in the same S and L bands. One candidate technology is an array of spread out individual phased array antennas, where individual phased array antennas can cope with use cases in the Telecom market requiring low size and low cost antennas (Mobility and IoT or generally TT&C for incoming missions) while the combination of several ones will allow to target satellite services requiring larger antennas.
A detailed trade-off was performed that took into account the different use cases (Telecom, Earth Observation, Navigation, Multifrequency, and Big Antennas). For each of the use cases, different antenna configurations were analysed and traded-off against each other, to come to a final design.
MULTIGS can provide a wide range of services for multiple satellite missions. The system considers phased array technologies with electronically beam steering providing multibeam capabilities for tracking several satellites in view at the same time. These characteristics are essential for the competitiveness of teleport operators in order to provide the service with a certain level of efficiency, as well as to ensure a continuity of the communications and a smooth handover between satellites.
The product will be focused on gateway functionalities for MSS constellations, as well as TT&C of small satellites as constellations, commonly performed in S-Band.
In our concept product, two-way L and S-band communication links with the satellites are established but considered the evolution of MSS, higher frequency bands (i.e., C, X; Ku) are also considered as potential candidates.
In addition, the product concept we present provides additional advantages in terms of CAPEX and OPEX, compared to traditional mechanically steered parabolic dishes. No moving parts or motors are present in MULTIGS leading to several advantages in terms of reliability, maintainability, OPEX reduction, reduced environmental impact (green technology) and environmental conditions tolerance (weather insensitive).
The proposed product is a multibeam Ground Station based on Active Array Antenna technologies for multiple simultaneous services (MULTIGS). It will have the capability to simultaneously track and communicate with multiple satellites in different orbits.
In contrast to mechanically steered dish antennas, phased array antennas provide agile beam, multibeam, and graceful degradation features. They also require less maintenance than the mechanically steered reflector antennas. With advances in microwave monolithic integrated circuit (MMIC) and packaging technologies, the phased array antenna has been evolved as a strong candidate for many present and future applications in satellite communications.
The ambition of the project is to arrive to a generic multi-beam ground station concept able to cope with TT&C communications for Navigation Satellite Systems or Radioastronomy applications on substitution of large reflectors. Since these applications require mostly S-Band (TT&C) or L-Band (VLBI), the product should be based on a modular concept in order to scale the product to other services and applications in the same S and L bands.
The system is modular and expandable – the design is built by repetition of a basic module that can be configured in order to provide a number of electronic steerable beams- such that it can be scaled and deployed in different configurations in order to match gradual operational requirements of further missions deployed.
The main elements of the MULTIGS product are:
Transmission/Reception Subsystem including Active Phased Array Antenna and RF frontend, depending on the requirements of the target application this block can be an individual phased array or a set of phased array as it has been explained before.
Beamforming Network in charge of performing the beam-steering function according to the control information received from the tracking subsystem.
Tracking Subsystem in order to acquire the signal and perform tracking. This can be implemented as additional reception antennas with dedicated elements to the tracking function in the case of high directivity antennas, or a tracking processor based on ephemerids (for lower antenna size).
Back-end including Signal Processor functionality, Control and clock reference generation and distribution to the rest of subsystems and elements in the system.
Ancillary elements such as; power supply and infrastructure.
During this project, the Product Concept has been defined during the Definition Phase. Next steps, will include breadboarding, prototyping the basic module, developing a full prototype, and the last step is to design and test the final product.
The Development Phase has been successfully completed. During this phase, we have analysed the requirements, traded off multiple design options, and selected a final concept.