Title :
A thin-rod approximation for the improved modeling of bare and insulated cylindrical antennas using the FDTD method
Author :
Nadobny, Jacek ; Pontalti, Rolando ; Sullivan, Dennis ; Wlodarczyk, Waldemar ; Vaccari, Alessandro ; Deuflhard, Peter ; Wust, Peter
Abstract :
A general and consistent integral finite-difference time-domain (FDTD) formulation on cubical grids for modeling of cylindrical antennas with or without dielectric coating is derived. No additional grid points or modifications of the integral paths are necessary. Instead, effective material properties are modified in the FDTD grid. Thus, even for insulated antennas, the simple cubical structure is maintained. Special integral factors are defined on cubical elements, which take into account the behavior of fields in all directions in the neighborhood of the antenna. Applying these factors to the gap region and along the antenna´s axis allows a correct modeling of the influence of the antenna´s thickness. Furthermore, integral factors derived for the antenna´s ends improve the modeling of the antenna´s length. The accuracy of the method is confirmed by a systematic comparison with analytical and numerical results.
Keywords :
approximation theory; coatings; dielectric properties; electric impedance; finite difference time-domain analysis; wire antennas; FDTD method; antenna length; antenna thickness; bare cylindrical antennas; cubical elements; cubical grids; dielectric coating; input impedance; insulated cylindrical antennas; integral factors; integral finite-difference time-domain formulation; material properties; thin-rod approximation; thin-wire antenna; thin-wire approximation; Antenna accessories; Coatings; Dielectrics and electrical insulation; Directive antennas; Finite difference methods; Impedance; Material properties; Resonance; Time domain analysis; Voltage;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2003.815420