An antenna with fractal PBG structure designed for modern UWB system

Abstract

For the requirements of ultra-wideband (UWB) antenna, we designed a meandered-line antenna with fractal PBG structure, which can completely cover all the frequency segments of UWB system (3.1 ̃ 10.6 GHz). The size of the antenna is minimized greatly, only 30 mm × 32 mm × 0.8 mm. The simulated results show that for VSWR less than 2, the working frequency segment of the antenna is 2.91 ̃ 11.53 GHz, at which the lowest return loss value S11 is -17.17 dB. Meanwhile, the antenna bandwidth is up to 8.62 GHz absolutely and 119.39% relatively; the frequency multiple bandwidth is up to 3.96 GHz. Considering the engineering processes, the influences of dielectric constant εr and thickness of circuit board on the antenna's performance are particularly studied. We also discussed the fractal PBG structure in detail, including its size and arrangement regulation. At last, the contrast analysis on different radiation characteristics of the antenna while being sticked on various materials has been done to validate the function stability.