Design of WLAN and WIMAX band rejection utilizing UWB planar antenna comprising a slit in the conductor planes

Abstract

A compact and low profile ultra wideband planar antenna comprises dual notched-band characteristics for WIMAX and WLAN are presented. UWB communication system is allocated between 3.1 and 10.6GHz, which coexisted with the WLAN and WIMAX frequency bandwidths at 3.3 to 3.6GHz, and 5 to 6GHz, repsectively. The coexistence between multiple frequency bandwidths possibly can cause interference into the communication systems such as data loss and signal disruption. Thus, it is essential to eliminate the coexisted frequency bandwidhs from UWB spectrum. The UWB planar antenna is costructed with a radiator of an elliptical-shaped, and half-ground element which is subjected to suppress the frequency bandwidth for 3.3 to 3.7 and 5 to 6 GHz. Slits are engraved in the elliptical radiator and ground element by etching the conductor elements. Slit shapes are designed in simple and optimized to realize the maximum band notch characteristics. Slit placements are scrutinized and the band notch characteristics are determined. It is considered that the slit in the ground element and the elliptical radiator have stimulated the band notches frequency bandwidths for 3.3 to 3.7 and 5 to 6 GHz, respectively. The UWB planar antennas are compared with the reference antenna and the results are verified.Measured reflection coefficient S11 for band notch peaks at the WLAN and WIMAX frequency bandwidths are about -3.0 and -4.0 dB, respectively. Radiation pattern co-polarizations in the H-and E-plane are in omni-and bi-directional, respectively. Maximum gain G is located in the -z -axis and -x -axis in H-and E-plane in the frequency of interest. Surface currents are distributed in the slit areas. Slits in the elliptical radiator and the ground element are not substantially affect the UWB planar antenna overall performances.