Wideband characteristics of built-in folded dipole antenna for handsets au11|^Atsushi Kajitani

This paper deals with built-in folded dipole antenna (BFDA) and the built-in folded monopole antenna (BFMA) have been introduced and analyzed. Those antennas have folded dipole and monopole element, respectively. They can be built in a small volume and placed very close to the rectangular ground plane (GP), which represents a shielding plate used in the handset unit. A folded loop is essentially a two-wire transmission line, folded at about a quarter-wavelength to foam an equivalent half-wave folded dipole, and yet appears as a one-wavelength loop antenna, from which the antenna is referred to as a folded loop. In this paper, the parameters related to the feed structure are optimized in order to obtain a wider bandwidth for the BFDA system, and the fundamental performances are analyzed in both theoretically and experimentally.