Fundamental characteristics of a planar folded dipole antenna with a feed line on the dielectric substrate

Recently, the many services for the cellular phone are spread. Therefore, the broadband antenna for handsets is required. In our previous paper [1], the planar folded dipole antenna (PFDA) with a feed line, which consists of two parallel lines has been introduced and its characteristics have been analyzed. As a result, it was found that PFDA with a feed line had a broadband characteristic and the feed line of a PFDA worked as an impedance transformer. The purpose of this study is to analyze the broadband characteristics of PFDA with a feed line on the dielectric substrate. We can expect that the resonant frequency of the antenna can be lowered by using the dielectric as the substrates, which leads to the miniaturization of the antenna. First, the parametric study on the feed line with respect to the length and spacing between two parallel lines is performed by using the electromagnetic simulator (CST Microwave Studio). Next, a prototype is fabricated and measured in order to verify the simulated results.