DocumentCode :
3195878
Title :
A planar near-field to far-field transformation using an equivalent magnetic current approach
Author :
Petre, P. ; Sarkar, T.K.
Author_Institution :
Dept. of Electr. & Comput. Eng., Syracuse Univ., NY, USA
fYear :
1992
fDate :
18-25 June 1992
Firstpage :
1534
Abstract :
A method is presented for computing far-field antenna patterns from near-field measurements. The method utilizes near-field data to determine equivalent magnetic current sources over a fictitious planar surface which encompasses the antenna, and these currents are used to ascertain the farfields. An electric field integral equation is developed to relate the near fields to the equivalent magnetic currents. A method of moments procedure is used to transform the integral equation into a matrix one. The matrix equation is solved with the conjugate gradient method (CGM), and, in the case of a rectangular matrix, a least-squares solution for the currents is found without explicitly computing the normal form of the equation. Near-field to far-field transformation for planar scanning may be efficiently performed under certain conditions by exploiting the block Toeplitz structure of the matrix and using CGM and the fast Fourier-transform (CGFFT), thereby drastically reducing computation and storage requirements. Numerical results are presented by extrapolating the far fields using experimental near-field data.<>
Keywords :
antenna radiation patterns; conjugate gradient methods; fast Fourier transforms; integral equations; least squares approximations; matrix algebra; CGFFT method; FFT; block Toeplitz structure; conjugate gradient method; electric field integral equation; equivalent magnetic current approach; far-field antenna patterns; least-squares solution; matrix equation; method of moments; planar near-field to far-field transformation; Antenna measurements; Antenna theory; Aperture antennas; Current measurement; Dipole antennas; Electric variables measurement; Integral equations; Magnetic field measurement; Transmission line matrix methods; User-generated content;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Antennas and Propagation Society International Symposium, 1992. AP-S. 1992 Digest. Held in Conjuction with: URSI Radio Science Meeting and Nuclear EMP Meeting., IEEE
Conference_Location :
Chicago, IL, USA
Print_ISBN :
0-7803-0730-5
Type :
conf
DOI :
10.1109/APS.1992.221746
Filename :
221746
Link To Document :
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