Novel Gaussian beam method for the rapid analysis of large reflector antennas

A relatively fast and simple method utilizing Gaussian beams (GBs) is developed which requires only a few seconds on a workstation to compute the near/far fields of electrically large reflector antennas when they are illuminated by a feed with a known radiation pattern. This GB technique is fast, because it completely avoids any numerical integration on the large reflector surface which is required in the conventional physical optics (PO) analysis of such antennas and which could take several hours on a workstation. Specifically, the known feed radiation field is represented by a set of relatively few, rotationally symmetric GBs that are launched radially out from the feed plane and with almost identical interbeam angular spacing. These GBs strike the reflector surface from where they are reflected, and also diffracted by the reflector edge; the expressions for the fields reflected and diffracted by the reflector illuminated with a general astigmatic incident GB from an arbitrary direction (but not close to grazing on the reflector) have been developed in Chou and Pathak (1997) and utilized in this work. Numerical results are presented to illustrate the versatility, accuracy, and efficiency of this GB method when it is used for analyzing general offset parabolic reflectors with a single feed or an array feed, as well as for analyzing nonparabolic reflectors such as those described by ellipsoidal and even general shaped surfaces.

[1]  Derek A. McNamara,et al.  Introduction to the Uniform Geometrical Theory of Diffraction , 1990 .

[2]  S. Raz,et al.  Gabor representation and aperture theory , 1986 .

[3]  A. Michaeli.  Elimination of infinities in equivalent edge currents, part I: Fringe current components , 1986 .

[4]  E. Knott,et al.  The relationship between Mitzner's ILDC and Michaeli's equivalent currents , 1985 .

[5]  P. Pathak.  Techniques for High-Frequency Problems , 1988 .

[6]  G. Deschamps,et al.  A uniform asymptotic theory of electromagnetic diffraction by a curved wedge , 1976 .

[7]  Ehud Heyman,et al.  Pulsed beam diffraction by a perfectly conducting wedge: local scattering models , 1995 .

[8]  A. Michaeli.  Elimination of infinities in equivalent edge currents, Part II: Physical optics components , 1986 .

[9]  P. Pathak,et al.  High frequency techniques for antenna analysis , 1992, Proc. IEEE.

[10]  A. D. Yaghjian,et al.  Incremental diffraction coefficients for planar surfaces , 1988 .

[11]  R. Kouyoumjian,et al.  A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface , 1974 .

[12]  F. Hasselmann,et al.  Asymptotic analysis of parabolic reflector antennas , 1982 .

[13]  Hsi-Tseng Chou,et al.  Uniform asymptotic solution for electromagnetic reflection and diffraction of an arbitrary Gaussian beam by a smooth surface with an edge , 1997 .

[14]  P. Ufimtsev,et al.  Method of Edge Waves in the Physical Theory of Diffraction , 1971 .

[15]  Hsi-Tseng Chou,et al.  Feed array synthesis for reflector antennas in contoured beam applications via an efficient and novel Gaussian beam technique , 2001 .

[16]  High‐frequency analysis of Gaussian beam scattering by a two‐dimensional parabolic contour of finite width , 1995 .

[17]  L. B. Felsen,et al.  Systematic study of fields due to extended apertures by Gaussian beam discretization , 1989 .

[18]  K M Mitzner,et al.  Incremental Length Diffraction Coefficients , 1974 .

[19]  Prabhakar H. Pathak,et al.  Analysis of EM penetration into and scattering by electrically large open waveguide cavities using Gaussian beam shooting , 1991, Proc. IEEE.

[20]  Thomas B. A. Senior,et al.  Comparison of three high-frequency diffraction techniques , 1974 .

[21]  L. B. Felsen,et al.  Gaussian beam analysis of propagation from an extended plane aperture distribution through dielectric layers. I. Plane layer , 1990 .

[22]  E. V. Jull,et al.  Beam diffraction by planar and parabolic reflectors , 1991 .

[23]  E. V. Jull,et al.  Two-dimensional beam diffraction by a half-plane and wide slit , 1987 .

[24]  Y. Rahmat-Samii,et al.  A generalized diffraction synthesis technique for high performance reflector antennas , 1995 .