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Far-field formulation of a Cassegrain reflector using a novel illumination function and aperture field integration

Published online by Cambridge University Press:  19 September 2012

Mohammad Asif Zaman  and
MD. Abdul Matin
Mohammad Asif Zaman*
Affiliation:
Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh
MD. Abdul Matin
Affiliation:
Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh
*
Corresponding author: M. Asif Zaman Email: [email protected]; [email protected]
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Abstract

In this paper, the far-field pattern of a Cassegrain reflector is formulated. A novel illumination function is used to approximate the field distribution at the aperture of the reflector. The defined illumination function takes into account the central aperture blockage created by the subreflector. Using the illumination function, a closed-form expression describing the far-field radiation pattern of the Cassegrain reflector is formulated. The radiation pattern obtained from the derived equation is compared with the results obtained from physical optics and physical theory of diffraction. The results are found to be consistent with each other. It is found that the derived results show an impressive accuracy of 99.8% over the main-lobe region. The accuracy is found to be over 91 and 84% for the first and second significant side-lobe region, respectively, which can be considered satisfactory for many applications.

Keywords

Aperture blockageAperture field integrationCassegrain reflectorFar-fieldillumination functionRadiation pattern
Type
Research Papers
Information
International Journal of Microwave and Wireless Technologies , Volume 4 , Issue 6 , December 2012 , pp. 629 - 634
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2012

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References

REFERENCES

[1]Rahmat-Samii, Y.: In Reflector Antennas, Volakis, J.L. (Ed.), Antenna Engineering Handbook, chapter 15, 4th ed., McGraw-Hill, USA, 2007.Google Scholar
[2]Balanis, C.A.: Antenna Theory Analysis and Design, 3rd ed., John Wiley & Sons, New Jersey, USA, 2005.Google Scholar
[3]Silver, S.: Microwave Antenna Theory and Design, McGraw-Hill, New York, USA, 1949.Google Scholar
[4]Baars, J.W.M.: The Paraboloidal Antenna in Radio Astronomy and Communication, Springer, New York, USA, 2007.Google Scholar
[5]McNamara, D.A.; Pistorius, C.W.I.; Malherbe, J.A.G.: Introduction to the Uniform Geometrical Theory of Diffraction, Artech House, Norwood, MA 02062, USA, 1990.Google Scholar
[6]Yaghjian, A.: Equivalence of surface current and aperture field integrations for reflector antennas. IEEE Trans. Antennas Propag., 32 (1984), 1355–1358.Google Scholar
[7]Bucci, O.; Franceschetti, G.; Pierri, R.: Reflector antenna fields – an exact aperture-like approach. IEEE Trans. Antennas Propag., 29 (1981), 580–586.Google Scholar
[8]Zaman, M.A.; Choudhury, S.M.; Gaffar, M.; Matin, M.A.: Modeling the illumination function of a Cassegrain reflector for a corrugated horn feed and calculation of the far field pattern, in Proc. Loughborough Antennas & Propagation Conf., November 2009, 101–104.Google Scholar
[9]Richardson, R.J.: A new family of illumination functions. IEEE Trans. Antennas Propag., 18 (1970), 284–285.Google Scholar
[10]Pace, J.R.: Aperture blockage by a subreflector in a Cassegrain antenna system. Electron. Lett., 4 (1968), 500–501.Google Scholar
[11]Lamb, J.W.; Oliver, A.D.: Blockage due to subreflector supports in large radiotelescope antennas. Proc. IEE Microw. Antennas Propag., 133 (1986), 43–49.CrossRefGoogle Scholar
[12]Solovey, A.; Cardiasmenos, A.; Mittra, R.: An optical blockage illumination correction factor for circular reflectors, in Proc. IEEE Antennas and Propagation Society Int. Symp., June 2007, 5155–5158.Google Scholar
[13]Granet, C.: Designing axially symmetric Cassegrain or Gregorian dual-reflector antenna from combinations of prescribed geometric parameters. IEEE Antennas Propag. Mag., 40 (1998), 76–82.Google Scholar
[14]Munro, E.W.; Whitaker, A.J.T.; McInnes, P.A.: Calculations of the secondary radiation pattern for a paraboloid reflector with a given illumination function and feed position. Electron. Lett., 9 (1973), 234–235.Google Scholar
[15]Polyanin, A.D.; Manzhirov, A.V.: Handbook of Mathematics for Engineers and Scientists, Chapman & Hall/CRC, New York, USA, 2007.Google Scholar