Design and analysis of finite arrays of circumferentially oriented printed dipoles on electrically large coated cylinders
Author
Güner, Barış
Advisor
Ertürk, Vakur B.
Date
2004Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
73
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Abstract
Conformal antennas and arrays are used in a wide range of applications including
mobile communication systems, missiles, aircrafts and spacecrafts. In these
applications, the conformality is required for aesthetic and aerodynamic constraints
and reducing the radar cross-section. Antennas and arrays conformal to
the cylindrical host bodies are particularly important since cylindrical geometry
can be used to approximate most of the practical problems and it is a canonical
geometry. However, the available design and analysis tools for antennas/arrays
conformal to cylindrical host bodies are either approximate methods or restricted
to small arrays. Recently, a hybrid method based on Method of Moments (MoM)
combined with a Green’s function in space domain is proposed to solve the aforementioned
problem. In this work this method is used to analyze finite, phased
arrays of circumferentially oriented printed dipoles conformal to the dielectric
coated electrically large circular cylinders. The accuracy and efficiency of the
method comes from the computation of the appropriate Green’s function which
is the kernel of the electric field integral equation to be solved via MoM. There
are three different high-frequency based representations for the Green’s function
in the spatial domain which are valid in different but overlapping regions: Planar
representation, steepest descent path (SDP) representation and the Fourier Series
(FS) representation. These different representations are used interchangeably to
obtain the most accurate solution that requires the least amount of computational
time. Several modifications on the method are made in this work to increase the
efficiency and accuracy of the solution. The effects of the array and host body
parameters on the performance of the array are presented. The results are compared
with a previously published spectral domain solution to show the accuracy of the method. Also, performance comparisons with those of the cylindrical arrays
of axially oriented dipoles and planar arrays are made to observe the effects
of curvature and the dipole orientation on the performance of the array.