This work presents an experimental study in W band about the behavior of a plane Fresnel reflector when the feeder changes its position on the surface of a sphere whose centre is the same of the Fresnel plate zones. For this purpose, an experimental system based on seven Fresnel plate zones and two different levels has been developed. The center frequency of the reflector is 96 GHz, the focal length is 100 mm and height between levels is 0.78 mm. Based on this Fresnel reflector, an experimental set up has been developed. The horn antenna feeder is fixed and situated in far field and the receiver is also a horn antenna located at the Fresnel focal distance. Both the reflector and the receiving antenna have some rotation capability to enable measurements from different angles. The experimental results show a good, stable behavior in gain versus the angular position of the feeder. This special property of Fresnel reflectors is impossible in parabolic reflectors and consequently, Fresnel reflectors could be used in new applications as radar imaging, increasing the radar field of view or improving the resolution by means of several squint feeders working simultaneously on the same lens or reflector. Therefore, the main objective of this paper is to analyze the behavior of this experimental set up for developing new Fresnel reflector-based applications.
1. Minin, O. V. and I. V. Minin, "Diffractional Optics of Millimetre Waves," IoP Publishing Ltd., 2004. doi: ISBN: 07503090775
2. Gutierrez-Rios, J. and J. Vassal'lo, "Technological aspects of Fresnel zone reflectors," Advances on Antennas, Reflectors and Beam Control , 85-114, 2005. doi:ISBN: 81-308-0067-5
3. Vassal'lo, , J., , "Recent developments of the INTA/CSIC collaboration on antennas," 7th International Symposium on Recent Advances in Microwaves Technology, ISRAMT' 99, , 1999.
4. Ruiz-Cruz, , J. A. and J. L. Masa-Campos, "Antennas and circuits of high frequency," Theme VII, Second Part, Master on Informatics and Telecommunication Engineering, Autonomous University of Madrid, 2007.
5. Li, , B., , K. J. Lee, H. T. Chou, and W. Gu, "A polarization compensation approach utilizing a paraboloid photonic-crystal structure for crossed-dipole excited reflector antennas," Progress In Electromagnetics Research, Vol. 85, 393-408, 2008. doi:10.2528/PIER08081703
6. Bolli, , P., G. Mazzarella, G. Montisi, and G. Serra, "An alternative solution for the reflector surface retrieval problem," Progress In Electromagnetics Research, Vol. 82, 167-118, 2008. doi:10.2528/PIER08021102
7. Gutierrez-Rios, , J. and J. Vassal'lo, "New reflector technology with reconflgurable beam pattern," 29th ESA Antenna Workshop on Multiple Beams and Reconflgurable Antennas, Apr., 2007.
8. Pedreira, , A., J. Vassal'lo, and , "Conformed beams using Fresnel's zones flat reflectors," 4th COST 260 Workshop on Smart Antenna Design and Technology, European Action COST 260 , 2000.
9. Le Grand, , Y., Form and Space Vision, Indiana University Press, Bloomington, 1967.
10. Hristov, , H. D. , Fresnel Zones in Wireless Links, Zone Plate Lenses, Artech House, 2000. doi:ISBN 0-89006-849-6