A flexible broadband antenna with fan-shaped and trapezoidal elements formed on printed circuit board for ultra-wideband radio

Ultra wideband (UWB) technology draws attention as a promising technology in order to materialize ubiquitous network. However, it is difficult to obtain the ultra-wideband antenna that performs excellent over a broad frequency band from 3.1 GHz to 10.6 GHz in UWB radio communication. From a view point of cost, production, and miniaturization of devices, ultra-wideband antenna with a feeder line should be formed on a printed circuit board. Furthermore, considering building an antenna into electronic equipment, it is indispensable to develop and materialize the thinner and flexible antennas. In this paper, a flexible broadband unbalanced dipole antenna with fan-shaped and trapezoidal elements formed on the flexible printed circuit board including feeder line for ultra-wideband radio was investigated and developed. As a result, it is found that the VSWR less than 2.0 in the frequency range of 2.8 GHz to 12 GHz, with relative band width of 128 %, was obtained from the measurement.