engleski

Ultra Wideband Antenna of Tilted Triangular Monopoles

To meet the challenging demands of modern wireless communications, such as high speed data transmission and multimedia services, the ultra wide band (UWB) and multiband antennas have made rapid advances in the past few years [1-7]. One of the possible solutions for achieving very large impedance bandwidth, is the use a self-complementary antenna [8]. Unfortunately, when the angle of the metallic part is 90 degrees, the input impedance is theoretically equal to one half of the free space intrinsic impedance. Therefore it is very difficult to match such an antenna to the 50 ohm characteristic impedance in a wide frequency band. In this paper, we propose two novel antennas for ceiling-mount base station applications. Conceptually, they are based on the self-complementary principle, but overcome the mentioned drawbacks of such antennas. Two slightly different topologies with triangular monopoles are presented to improve the impedance matching and the pattern stability across the operating bandwidth from 1 to 5.5 GHz. Therefore, both experimental and computational results of the antennas impedance and radiating properties are shown. The numerical analysis of the antennas are performed using a commercial computer software package (FEKO), based on the method of moments. The proposed antennas exhibit acceptable UWB performances, good radiation properties, simple construction, and show potential for finding applications in ceiling-mount base stations and small terminals, covering simultaneously GSM, PCS, IMT-2000, WLAN (2450 MHz), and ISM 2.4 and 5 GHz bands.

antenna; ultra wideband antenna; terminal antenna

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