A novel compact design of USB dngle antenna for bluetooth applications

Compact and low-cost design has been favorable and become a trend in developing modern wireless communications products. This paper presents a compact design of printed wire inverted-F antenna with parasitic ground extrusion on a low cost FR4 PCB substrate. In general, a small antenna suffers a narrow bandwidth performance. In this study, we successfully enhance the antenna bandwidth by using two resonances coupling between the feeding strip and the grounded parasitic element. The optimized antenna design takes into account the proximity effects of the existing USB circuitry and packaging. An antenna area of 6.5mm × 12mm is achieved in a USB dongle module with total area of 12mm × 20mm, operated at 2.4 GHz. The experimental results from the fabricated prototypes are also included.