Using Inflatable Antennas for Portable Satellite-based Personal Communications Systems
- Paper number
IAC-05-B3.4.02
- Author
Ms. Naomi Mathers, Victorian Space Science Education Centre, Australia
- Coauthor
Dr. Kamran Ghorbani, Royal Melbourne Institute of Technology (RMIT), Australia
- Coauthor
Prof. Lachlan Thompson, Royal Melbourne Institute of Technology (RMIT), Australia
- Year
2005
- Abstract
Satellite-based personal communications systems (SPCS) have the ability to connect mobile personnel with a central support network in both military and disaster management situations [1]. These systems require lightweight equipment that is quickly and easily deployed and operated in a variety of environments. Parabolic dish antennas provide the high gain required for direct satellite communication but their size and weight severely limit portability.
The use of inflatable structures in the space environment has been successful in reducing mass by at least 50% and stowed volume by up to 75% [2]. The deployment of the Inflatable Antenna Experiment (IAE) demonstrated that the shape and surface accuracy required for communication applications was achievable in the space environment [2].
For inflatable structures to be applied to portable land-based communication it must be demonstrated that the required shape and surface accuracy can be maintained whilst under terrestrial conditions. This has been achieved through material selection, structural design and internal pressure. The flexible nature of inflatable, or gossamer, structures eliminates the possibility of validating the shape accuracy via contact methods. The radiation characteristics of an antenna are directly related to the shape and surface accuracy of the structure thus it is possible to use the radiation patterns as an indirect method of assessing the accuracy of the structure.
Using this technique it was demonstrated that an inflatable structure could match the performance of a rigid structure under terrestrial conditions with the manufacture of a gossamer feed horn [3] and a 0.5m diameter gossamer parabolic dish reflector [4] designed to operate at 12.5 GHz.
This paper examines the mechanisms used to achieve the shape and surface accuracy required. The radiation patterns used to assess the gossamer feed horn and parabolic dish are presented to demonstrate that it is possible to construct an inflatable structure that matches the performance of a rigid structure under terrestrial conditions. The results obtained justify progressing to the next stage and integrating the dish and feed horn into a fully inflatable dual-reflector antenna.
The result was an inflatable antenna suitable for portable, re-usable, low-cost, land-based direct satellite communication. This design can be replicated in various sizes to operate at a range of frequencies making it suitable for multiple applications such as mobile military communication, emergency response communication and tele-medicine, and media broadcasting in remote areas.
References 1. Mahoney, T., Kerr, P., Felstead, B., Wagner, L., Wells, P., Cunningham, M., Ryden, K., Baumgartner, G., Demers, H., Dayton, W.L., Jeromin, L., Spink, B., “An Investigation of the Military Applications of Commercial Personal Satellite Communications Systems” MILCOM 99 IEEE 0-7803-5538-5 1999 2. Jenkins, C.H., Freeland, R.E., Bishop, J.A., and Sadeh, W.Z., (1998) “An Up-to-Date Review of Inflatable Structures Technology for Space-Based Applications,” Space 98 Conference, Albuquerque, NM, April 27, 1998. 3. Mathers N., Ghorbani K. and Thompson L, “Development of Inflatable Feed for Inflatable Parabolic Dish Antenna”, Australian Space Science Workshop (ASSW), Sydney, Australia, July 2003. 4. Mathers N., Ghorbani K. and Thompson L, “Development of a Gossamer Parabolic Dish Reflector” 13th JINA Symposium on Antennas, Nice, France, 8-10th Nov 2004
- Abstract document
- Manuscript document
IAC-05-B3.4.02.pdf (🔒 authorized access only).
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