The scope of the activity is the development and the market assessment of a flat multi-band antenna system for vehicular terminals. The system will be able to satisfy simultaneously the requirements of several Mobile Satellite Systems (MSS) applications such as:
- Reception of commercial broadcasting transmissions in L, S and Ku Band: Satellite Digital Audio Broadcasting (S-DAB), Satellite Digital Video Broadcasting (DVB-S) and Data Casting. The main service providers are WorldSpace, XM Radio, Eutelsat and Astra.
- Accurate positioning and navigation systems. Reception of GPS/Galileo + EGNOS signals (L-band). Main applications: intelligent car navigation systems, road traffic management etc.
- Mobile telecommunication systems. Either regional coverage systems based on GEO satellites (Inmarsat, Thuraya, ACE, &) and global coverage systems (Iridium, S-UMTS) will be addressed.
The antenna will be developed while taking into account the requirements of vehicular mobile applications, namely aerodynamic, mechanical strength, lightweight and small size. Car and boat applications will be the main targeted applications, but train and plane applications will also be considered. In parallel with the technical development, a commercial feasibility study will be performed. This will analyse all the aspects related to the commercialization of the antenna system.
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The aim of this activity is the development of a multi-antenna vehicular front-end for different satellite-based mobile communication systems. This new type of front-ends will need to be flat, compact, lightweight and easily integrated onto thin curved surfaces. Therefore, different realization/integration strategies will be analyzed in order to obtain an optimal solution. Another issue will be the development of an active array with electronic beam steering for the reception of Ku-band signals. This activity will require the development of custom Low Noise Amplifiers and phase shifters.
The availability on the market of working, low-cost equipment for ground terminals will be a key issue in the deployment of future mobile satellite communication networks. The use of a 'multi-band multi-beam front-end' will enable access to several applications through the installation of only one compact device. One front-end for each application is being considered as this approach should reduce the costs of production, one of the key factors for vehicle manufacturer acceptance, and the cost of integration into the vehicles.
Moreover, such multi-application front-end will be developed entirely using printed technology. This approach will improve the aerodynamic properties of the device as well as the opportunity to conceal it in the profile of the vehicle, another key factor for integration into the next generation of cars.
The overall antenna system will be composed of two main elements. The first element will be composed by a set of flat printed single/multi-band antennas for different applications in L and S band like Satellite Digital Audio and Data Broadcasting (Worldspace), navigation (GPS, Galileo) and satellite mobile communications (S-UMTS, Inmarsat, Thuraya, &). Three main types of antennas will be combined in a single structure to cover the different services:
- Antenna with conical beam coverage and with single and dual circular polarization for mobile communications systems based on GEO satellites network (i.e. Digital Audio Broadcasting)
- Antenna with single band hemispherical beam circularly or linearly polarised for navigation systems and existing global coverage communication systems (Globalstar, Iridium)
- Multi-band antenna with hemispherical pattern for future global communication systems (S-UMTS).
Low Noise Amplifiers as well as RF switches will be integrated in the antennas in order to obtain active antennas with polarisation switching capability.
The second element of the system will be a steerable antenna array for the reception of Direct Video Broadcasting at Ku band. The array will be composed of flat wideband linearly polarised printed elements fed by a corporate network. Low noise amplifiers will be embedded in the feeding network to optimise the gain of the entire array. A hybrid electronic and mechanic tracking mechanism will be used for the beam pointing system. The array will be designed with two types of radiating elements, one for linear polarisation and one for circular. The complete array will be composed by 32 linear sub-arrays. Each sub-array will be connected to a voltage controlled phase shifter, which will control the electronic scanning of the array. The 32 sub-arrays will be then combined in the main port of the antenna.
The activity will be subdivided in four main phases:
- System requirements and specifications.
Preliminary market research and identification of main commercial application. Definition of antennas requirements and technical specifications.
- Breadboards development and test.
Development of single antenna breadboards for L, S and Ku band.
Test/validation of L and S band antennas + Ku band sub-array.
- Multi-band prototype development and test.
Development of multi-antenna prototype for L and S band.
Complete breadboard of Ku-band steerable array.
Test/validation of final prototypes.
- Commercial feasibility
Definition of marketing and financial plan.
Definition of product development plan.
Identification of strategic partnerships for production and commercialisation.
The technical and commercial activity of the project is completed.
Field trials with the prototype of WorldSpace, Thuraya and GPS have been successfully performed in different geographical positions. The definition of an industrial version is in progress.
The validation of the Ku-band DVB-S antenna is completed. The definition of the development phase for the realisation of an industrial prototype is in progress.