Browsing by Subject "Printed antennas"

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    Analysis of finite arrays of axially directed printed dipoles on electrically large circular cylinders
    (IEEE, 2004) Ertürk, V. B.; Rojas, R. G.; Lee, K. W.
    Various arrays consisting of finite number of printed dipoles on electrically large dielectric coated circular cylinders are investigated using a hybrid method of moments/Green's function technique in the spatial domain. This is basically an "element by element" approach in which the mutual coupling between dipoles through space as well as surface waves is incorporated. The efficiency of the method comes from the computation of the Green's function, where three types of spatial domain Green's function representations are used interchangeably, based on their computational efficiency and regions where they remain accurate. Numerical results are presented in the form of array current distributions, active reflection coefficient and far-field pattern to indicate the efficiency and accuracy of the method. Furthermore, these results are compared with similar results obtained from finite arrays of printed dipoles on grounded planar dielectric slabs. It is shown that planar approximations, except for small separations, can not be used due to the mutual coupling between the array elements. Consequently, basic performance metrics of printed dipole arrays on coated cylinders show significant discrepancies when compared to their planar counterparts. © 2004 IEEE.
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    Use of computationally efficient method of moments in the optimization of printed antennas
    (IEEE, 1999-04) Alatan, L.; Aksun, M. I.; Leblebicioglu, K.; Birand, M. T.
    Derivation of the closed-form Green’s functions and analytical evaluation of the method of moments (MOM) matrix entries have improved the computational efficiency of the significantly in the analysis of printed geometries. With this background in mind, an extension of this efficient numerical technique is to incorporate an optimization algorithm and to assess its potential as a computer-aided design (CAD) tool. Therefore, we have employed the Gradient search and Genetic algorithms, in conjunction with the electromagnetic (EM) simulation technique, to a number of representative examples of interest.