Design of a kind of wideband filtering antenna based on defected ground structure

Given the flaws in traditional cascading design of the filtering antennas, a kind of filtering antenna based on the defected ground structure (DGS) is proposed. It adopts the method of co-design to integrate the filter and the antenna into one substrate, resulting in a miniaturized size of 34 mm×30 mm. In the design, the structure with dumbbell shape is etched on the ground of dual-band antenna, aiming for the low-pass property of the filtering antenna. The simulated results show that the filtering antenna's co-design can effectively enlarge the bandwidth of the pass-band and suppress the bandwidth of T-patch, whose pass-band can cover the bandwidths of wireless local area network (WLAN) 2.4 GHz, wideband code division multiple access (WCDMA) 2.1 GHz, long term evolution (LTE) 2.3/ 2.5/ 2.6/ 2.8 GHz etc. In addition, the filtering antenna's physical module is fabricated and measured, whose test results are basically consistent with the ones of simulation. Moreover, the filtering antenna with liner polarization has a good radiation pattern of omni-direction, and can be applied to the terminals of wireless mobile system.