An asymptotic closed-form microstrip surface Green's function for the efficient moment method analysis of mutual coupling in microstrip antennas

IEEE Trans. Antennas Propagat.

Rojas

2002

Abstract-A new method to evaluate the surface fields excited within the paraxial (nearly axial) region of an electrically large dielectric coated circular cylinder is presented. This representation is obtained by performing the Watson's transformation in the standard eigenfunction solution and using the fact that the circumferentially propagating series representation of the appropriate Green's function is periodic in one of its two variables. Therefore, it can be approximated by a Fourier series where the two leading terms of the expansion yield engineering accuracy in most cases. This work can be used in conjunction with a method of moments solution for the design/analysis of conformal microstrip antennas and arrays. Numerical results are presented and compared with a standard eigenfunction expansion.

Section: Numerical Resultsmentioning

confidence: 99%

Section: B Componentmentioning

confidence: 99%

Paraxial space-domain formulation for surface fields on a large dielectric coated circular cylinder

IEEE Trans. Antennas Propagat.

Rojas

2002

“…where r pq and rЈ nm are the position vectors of the pq th and nm th dipoles and G xx (r pq ͉rЈ nm ) is the corresponding component of the (i) free-space dyadic Green's function for the free-standing dipole array, and the (ii) planar microstrip dyadic Green's function [16] for the printed dipole array. Finally, note that for a scattering problem where an external plane wave is incident on the array, in which the elements are now passive, the right-hand side of Eq.…”

Section: The Methods Of Moments Solutionmentioning

confidence: 99%

Efficient analysis of large phased arrays using iterative MoM with DFT‐based acceleration algorithm

Micro & Optical Tech Letters

Chou

2003

A discrete Fourier transform (DFT)-based iterative method of moments (IMoM) algorithm is developed to provide an O(Ntot) computational complexity and memory storages for the efficient analysis of electromagnetic radiation/scattering from large phased arrays. Here, Ntot is the total number of unknowns. Numerical results for both printed and free-standing dipole arrays are presented to validate the algorithm's efficiency and accuracy

“…It is used based on the assumption that for electrically large ( is large) material coated circular cylinders and small separations , the surface can be treated as locally flat. Hence, an efficient integral representation of the planar microstrip dyadic Green's function [24] is used for the self term evaluations of the impedance matrix. ii) The steepest descent path (SDP) representation of the dyadic Green's function [25], which is used away from both the paraxial (nearly axial) and the source regions (see [22]).…”

Section: B the Full-wave Solutionmentioning

confidence: 99%

Scan Blindness Phenomenon in Conformal Finite Phased Arrays of Printed Dipoles

IEEE Trans. Antennas Propagat.

Bakir

Rojas

et al. 2006

Abstract-Scan blindness phenomenon for finite phased arrays of printed dipoles on material coated, electrically large circular cylinders is investigated. Effects on the scan blindness mechanism of several array and supporting structure parameters, including curvature effects, are observed and discussed. A full-wave solution, based on a hybrid method of moments/Green's function technique in the spatial domain, is used to achieve the aforementioned goals. Numerical results show that the curvature affects the surface waves and hence the mutual coupling between array elements. As a result, the array current distribution of arrays mounted on coated cylinders are considerably different compared to similar arrays on planar platforms. Therefore, finite phased arrays of printed dipoles on coated cylinders show different behavior in terms of scan blindness phenomenon compared to their planar counterparts. Furthermore, this phenomenon is completely different for axially and circumferentially oriented printed dipoles on coated cylinders suggesting that particular element types might be important for cylindrical arrays.