The multi-band monopole antenna for USB devices

In this paper, a multi-band monopole antenna for Universal Serial Bus (USB) dongle applications is proposed and examined. The antenna is fabricated on an FR4 substrate of permittivity of 4.4, thickness of 0.8 mm, and loss tangent of 0.0245.The antenna consists of a bent monopole and an inserted strip horizontally. The bent monopole resonates a mode operation at 2.4 GHz and 5.2 GHz. The L-shaped monopole with the longest path inserted a short strip horizontally is to resonate a 5.8 GHz. From the simulated and measured return losses, the 10 dB operating bands cover the IEEE802.11 a/b/g WLAN application bands. The overall size of the antenna has a compact size of 37 × 10 × 0.8 mm³. In addition, the antenna with the simple structure and good performances is suitable for applying in WLAN system of small size.