Silindirik katmanlı ortamda momentler metodu uygulamaları için kapalı formda green fonksiyonlar

Closed-form Green?s function representations for cylindrically stratified media,which can be used in conjunction with a Method of Moments, are developed. Theclosed-form expressions are valid for all possible source and field points includingthe axial line (ρ = ρ and φ = φ ), which has not been available before.Closed-form expressions in cylindrically stratified media are first reported byTokgüz (M.S. thesis, 1997). However, the given expressions have accurate resultsoonly when the field point (ρ,φ,z) is far away from the source point (ρ ,φ ,z ), inparticular along the ρ-axis. Therefore, the expressions given by Tokgüz, can notobe used in a Method of Moments solution procedure for antenna problems.The spectral domain Green?s function components are modified in order toperform calculations for all possible source and field points. In the course ofobtaining closed-form expressions, the modified spectral domain expressions arecalculated efficiently and transformed to the spatial domain in the form of disc-rete complex images with the help of the generalized pencil of function method.Numerical results are presented in the form of mutual coupling between two tan-gential current modes which lie on the same air-dielectric interface, and comparedwith the eigenfunction results to assess the accuracy of the developed closed-formGreen?s function representations. Excellent agreement with the eigenfunction so-lution is obtained for arbitrary source and field locations.Keywords: Closed-form Green?s function representations, discrete complex imagemethod, generalized pencil of function method, mutual coupling, cylindricallystratified media.iii