PLANAR MULTILATERAL DISC MONOPOLE ANTENNA WITH VARIABLE BAND-NOTCH FUNCTION FOR BLUETOOTH/UWB APPLICATIONS

A planar multilateral disc monopole antenna for ultra-wideband (UWB) application is initially proposed. By asymmetrically reducing the ground plane structure, this proposed UWB antenna is able to integrate with the Bluetooth band, which provides a wide bandwidth from 2.27 to more than 12 GHz. In order to perform a rejection on the 5.2/5.8 GHz WLAN band signals, the technique of inserting an L-shaped stub into the microstrip feed line is proposed, and with the insertion of another L-shaped stub, a rejection on X-band signals is also achieved. All prototype antennas are theoretically and experimentally investigated, and the vital parameters such as the dimensions of the L-shaped stub for controlling the notched frequency and bandwidth are clearly illustrated. Near omni-directional patterns across the integrated Bluetooth and UWB bands with acceptable gain variation are measured, and good frequency domain characteristics are also observed, except in the notched band.