Contribution to the improvement on flat reflectors

José Ángel García, Ramón Gonzalo, Julio Gutiérrez-Ríos, Antonio Tazón and Juan Vassal'lo

As it is known, flat reflectors are a kind of antenna with high attractive performance for space and ground applications. Nevertheless, the experience of manufacturers with parabolic reflectors makes difficult to sponsor studies looking for alternatives to improve the actual technology, and provides better solutions to future challenges on the antenna market. The very low cost of paraboloids on ground technology, and the security on performance of manufactured prototypes for space technology, makes that manufacturers do not like be sponsors of a change of technology, because they have just a production line that is working correctly.
So the possibility to introduce flat reflectors on the antennas market is to provide solutions to future challenges with not possible solution for parabolic reflectors.
For example:

• to have several TV links with different satellites using the same reflector.
• to have TV links with two satellites having high angular separation from the receptor point of view, using an unique feeder and an unique reflector.
• to have a conformed transversal section of the main reflected beam, by means of specific conformed reflecting Fresnel zones

These three questions are just demonstrated on previous developments, and now, we are working on the following new developments:

• software of Fresnel reflector analysis for specific applications
• demonstration prototypes of different techniques on active reflectors looking for communications, scanning, and other new applications
• the use of a phase controlled reflection on a flat left handed material, to be applied on the design of Fresnel reflectors of different levels.

We have the aim to present all the partial results that we could obtain along this COST Action.