Application of characteristic modes to design the platform-mounted inverted-F antenna

Excitation of metal casing using bent and folded dipole antenna with three conductors

“…Excitation of the ground plane with small antennas has been considered for the utilization of the ground plane as the main radiator and to improve the radiation resistance. Characteristic mode analysis is a suitable method for determining the current distribution on a ground plane that behaves as an antenna [1][2][3][4]. In previous studies [1][2][3], an inductive coupling element (ICE), such as a small loop or slot antenna, is placed at current maxima, and a capacitive coupling element (CCE), such as a monopole antenna, is placed at current minima to excite current distribution.…”

“…However, to maintain the radiation efficiency of the excitation element, a low-profile excitation element has not yet been considered. In addition, since the number of the excitation element was four in [1], the power divider is required and the feeding circuit becomes a complex. In this study, we proposed a novel low-profile feeding structure with bent and folded dipole antenna with three conductors (BFDA) as a single excitation element for the metal casing with a similar size as the wavelength of the operating frequency.…”