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International Journal of Scientific and Engineering Research
ISSN Online 2229-5518
ISSN Print: 2229-5518 11    
Website: http://www.ijser.org
scirp IJSER >> Volume 2, Issue 11, November 2011
Analysis of A Lens Based Antenna Using Spherical Modes
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Author(s)
Prakash Biswagar, Dr. S.Ravishankar, S.Shashidhar
KEYWORDS
MBS, Smart Antenna, Dielectric Lens, SME, SVWF, SMCC
ABSTRACT
A fixed shaped beam antenna offers an excellent compromise between cost and system performance in high data rate systems operating in the frequency range of 5- 65 GHz. Shaped Dielectric Lenses perform the task of collimation and shaping, along with physically small feed antennas, to obtain multiple and shaped beams in a fixed set of directions. Lenses are inherently broadband, easy to fabricate, have lower dimensional tolerances, cost effective and act as radome for the primary radiators that are embedded inside or placed behind the lens. Earlier techniques for the analysis of shaped dielectric lenses, employed ray tracing methods of GO and PO, that are valid only in the far field of a primary point source type of radiator. But the dielectric lens is in the near field of finite sized primary radiators oriented at different angles and at different distances from the lens center. In this paper we discuss, a new accurate analytical procedure for the radiation pattern of a spherical lens excited by a rectangular patch. The lens is treated as a scatterer. Techniques for radial translation and spatial rotation of the small aperture Spherical Modal Complex Coefficients (SMCC) are utilized to align them to the phase center of the Dielectric Lens. The SMCC of the scattered fields due to the lens are then obtained by application of boundary conditions. Sample computations are performed to demonstrate the approach and supported by experimental results
References
[1] Carlos A Fernandes, ―Shaped dielectric lenses for Wireless Millimeter-Wave Communicatiobs‖, IEEE Antennas and Propagation Magazine, vol 41, No 5, pp 141-150, October 1999.

[2] Leandro Fernandes, ―Developing a system concept & Technologies for Mobile Broadband Communications‖ IEEE Personal Communications Magazine, pp 54-59, Feb 1995.

[3] Carlos A Fernandes, Jose G Fernandes, ―Performance of Lens Antennas in Wireless Indoor Millimeter Wave Applications,‖ IEEE Transactions on Microwave theory and Techniques, vol 47, No 6, pp 732-736, June 1999.

[4] William F Croswell, J S Chattejee, V Bradford Mason, ―Radiation from a homogeneous sphere mounted on a waveguide aperture,‖ IEEE Transactions on Antennas and Propagation, vol AP-23, No 5, pp 647-656, Sept 1975.

[5] H.S. Ho, C.J.Hagan, M.R. Foster, ―Microwave irradiation design using dielectric lenses,‖ IEEE Transactions on Microwave theory and Techniques, vol MTT-23, pp 1058-1061, Dec 1975.

[6] J. H. Bruning and Y.T. Lo, ―Multiple scattering of EM waves by spheres: Part I Multipole expansions and Ray optical solutions,‖ IEEE Transactions on Antennas and Propagation, vol AP-19, No 3, pp 378-390, May 1971.

[7] O.R. Cruzon, ―Translation addition theorems for spherical vector wave functions,‖ Quarterly of Applied Mathematics, Vol20, No 1, pp 15-24, 1961.

[8] A.R. Edmonds, Angular Momentum in Quantum Mechanics, Princeton University Press, Princeton, 1974.

[9] S.Ravishankar and M.S. Narasimhan, ―Multiple Scattering of EM Waves by Dielectric Spheres located in the near field of a source of Radiation,‖ IEEE Transactions on Antennas and Propagation, vol AP-35, No 4, pp 399-405, April 1987.

[10] Julius Adam Stratton, Electromagnetic Theory, New York, McGraw Hill Book Company, Chapter 7, 1941.

[l1] Constantine A Balanis, Antenna Theory - Analysis and Design, 2nd Edn, Singapore: John Wiley and Sons: Chapter 12, 2002.

[12] Arthur Ludwig, ―Near–Field Far-Field Transformations Using Spherical-Wave Expansions,‖IEEETrans. Antennas Propgat, vol.AP-19, N0.2, pp 214-220 March 1971.

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