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.    ABSTRAK: Antena jalur lebar paling satah yang padat dan bersusuk rendah telah diperkenalkan dan terdiri daripada dua ciri lebar-takik bagi WIMAX dan WLAN. Sistem komunikasi UWB berada pada 3.1 dan 10.6GHz, bertindan dengan jalur lebar frekuensi WLAN dan WIMAX yang berada pada 3.3 hingga 3.6GHz, dan 5 hingga 6GHz, masing-masing. Sifat bertindan antara beberapa jalur lebar frekuensi mungkin akan menyebabkan gangguan pada sistem komunikasi seperti kehilangan data dan gangguan isyarat. Oleh itu, adalah penting bagi membuang jalur lebar frekuensi yang bertindan dengan spektrum UWB. Antena satah UWB telah dibina dengan radiator pemancar berbentuk elips, dan unsur separuh-bumi (lapisan asas) dibawah jalur lebar frekuensi pada 3.3 hingga 3.7 dan 5 hingga 6 GHz. Jalur celahan telah diukir pada radiator elips dan lapisan asas dengan mengukir unsur konduktor. Jalur celahan telah direka mudah dan dioptimumkan bagi mencapai jalur takik maksimum. Kedudukan jalur celahan diteliti dan ciri-diri jalur takik diperolehi. Jalur celahan pada lapisan asas dan radiator elips diperhatikan menyebabkan frekuensi jalur lebar takik sebanyak 3.3 hingga 3.7 dan 5 hingga 6 GHz, masing-masing. Antena satah UWB dibandingkan dengan antena rujukan dan dapatan kajian telah disahkan tidak mempengaruhi keputusan antena planar UWB dengan ketara. Ukuran pantulan pekali S11 yand diukur pada frekuensi jalur lebar takik WLAN and WIMAX adalah -3.0 dan -4.0 dB, masing-masing. Corak pancaran radiasi ko-polar pada satah H- dan E- adalah omni- dan bi-arah, masing-masing. Kekuatan isyarat maksima G berada di paksi –z dan –x pada satah H- dan E- pada frekuensi yang dipilih. Elektrik pada permukaan tersebar dalam kawasan jalur celahan. Celah radiator elips dan lapisan asas tidak mempengaruhi prestasi keseluruhan antena satah UWB.