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Objectives
The objective of this project is to investigate lens antennas, and their ability to provide a cost-effective solution for Satcom on-the-move ground terminals. Lens antennas are associated with a high directivity, and beam scanning can be obtained by moving only the feed. Moreover, multiple simultaneous beams can be obtained in the same aperture by using multiple feeds displaced along the focal arc or surface. However, lenses suffer from a large physical size. In this project, we investigate different techniques for providing a more compact lens antenna solution, while maintaining the high-quality radiation characteristics of lens antennas. The goal is to develop antennas that can provide a high directivity and wide-angle steerable radiation patterns at a low cost and with a compact size.
Challenges
Conventional lens antennas provide attractive properties in terms of directivity and scanning. However, the size of lens antennas is, for some applications, prohibitive. Related to this, there are two main challenges in this project:
- To reduce the height of the lens so that it is compliant with ground mobile environments. We investigate lens compression within the framework of transformation optics and other techniques.
- To retain the attractive properties of lens antennas after the size reduction.
System Architecture
The antennas developed in this activity provide a mechanically steerable beam that require movement of only a small part of the system when steering. The beams can also be electronically switched if the feeding system of the developed antenna is modified. The architecture of the antenna is composed of two main parts.
- Gradient index lens, which provides the high gain. We develop the lens to be appropriate for manufacturing with 3D printing to ensure that the cost of the device is low. The height of the lens is compressed to ensure that the lens antenna does not protrude too much from its platform.
- Circularly polarized feeding that can be moved along the focal curve of the lens. The feeding system is designed to provide low axial ratio and a tapered illumination of the lens aperture so that the side lobe level is low.
Plan
The project is divided into four phases:
- Review of product requirements and available state-of-the-art.
- Study of different compression techniques and the applicability to the lens design. Different antenna solutions are proposed and verified in simulations.
- Validation of the most promising of the proposed designs. The designs are also compared to existing solutions in the literature.
- Link test using the antenna and a satellite in orbit.
Current Status
The project is completed, and the concepts are experimentally verified in a lab environment and with initial tests in the real operational environment.
