Characteristics of U-Shaped Folded Dipole Antenna for Handsets

Atsushi KAJITANI  Yongho KIM  Hisashi MORISHITA  Yoshio KOYANAGI  

B - Abstracts of IEICE TRANSACTIONS on Communications (Japanese Edition)   Vol.J92-B   No.3   pp.567-575
Publication Date: 2009/03/01
Online ISSN: 1881-0209
Print ISSN: 1344-4697
Type of Manuscript: PAPER
mobile handset,  folded dipole antenna,  feeding point,  current flow on the GP,  bandwidth,  

Full Text(in Japanese): PDF(1.7MB)
>>Buy this Article

The latest trends in handset unit used in the cellular phone is to reduce the size and the weight. Antennas used for such handsets must also follow downsizing of the handset unit yet keeping the antenna performance unchanged or even improved, and built-in antennas are becoming more intense requirement for handset antennas. Furthermore, the antenna structures which induce less current flow on the ground plane, so reducing the effects on the antenna performances by human body. In this paper, the parameters related to the feed structure are optimized in order to improve the bandwidth characteristics of the U-shaped Folded Dipole Antenna for Handsets (UFDA) in which the self balanced effects are still retained, and the fundamental performances are analyzed both theoretically and experimentally. As a result, it has been confirmed that the antenna, which is introduced here, has self-balanced effect with the bandwidth (S11-10 dB) of 520 MHz (29%) at the center frequency of 2,600 MHz.