Polarization Diversity with Genetic Parallel Printed Dipole Antennas for Bluetooth and WiMAX Applications

Abstract

Multipath propagation effect degrades usually the wireless system performances. Antenna Diversity in one of the several methods that have been studied to mitigate this phenomena. This technique can overcome the multipath fading improving the overall performance of communication system. In order to study the impact of the wireless channel and perform antenna diversity, two parameters must be evaluated: the mean effective gain, and the correlation coefficient between the antennas. Parallel Printed Dipole antennas have been succesfully used in mobile base station development, showing either broadband or multiple-band properties besides its low cost. However, polarization diversity parameters have not been analysed since these antennas have not been yet considered in mobile devices and diversity applications . In this paper, a polarization diversity schema comprised of two dual-printed dipole antennas for bluetooth and WIMAX applications operating in 2.4-2.4835 GHz and 3.5 GHz frequency bands are presented. Genetic Algorithm optimization (GA) is applied first, to a classical dual band printed dipole antenna schema, second to a pre-fractal tree parallel printed dipole to achieve a more compact radiator. Frequency performance of both antennas is introduced showing a VSWR< 1.5 for a input impedance of 50 Ohms. Later on, A diversity antenna based on the pre-fractal configuration is studied in terms of Mean effective gain (MEG) and correlation coefficient for indoor and outdoor scenarios. Results shows that MEG is nearly the same in both environments with a low correlation between the elements which means that diversity gain can be achieved using this schema.

Novel design of printed multiband antenna for wireless applications

“…A novel coplanar waveguide antenna for dual-band WLAN applications was designed in [5]. On the other hand, various structured have been presented in [6][7][8] for the multiband WiMAX applications. In [6], two dual-printed dipole antennas were presented.…”

“…On the other hand, various structured have been presented in [6][7][8] for the multiband WiMAX applications. In [6], two dual-printed dipole antennas were presented. A dual-band printed dipole antenna with parasitic element was proposed in [7].…”

The design of printed rhomb‐shaped antenna with slits for WiMAX systems

“…The technology can reach a theoretical 30-mile coverage radius and achieve data rates up to 75 Mbps for mobile broadband wireless access and internet access for wireless users becomes possible [1]. Particularly, great interests in designing such a functional antenna for WiMAX by using various structures have been presented in literature [2][3][4][5][6][7]. In [2], the antenna comprises a wideband stubby metal-plate monopole antenna for WiMAX or IEEE 802.16e operation in the frequency bands between 2 and 6 GHz and has dimensions of 70 ϫ 100 mm 2 .…”

“…And, maximum antenna gains measured of 1.7 and 2.9 dBi in lower band and higher band, respectively. In [6], dual printed dipole antenna (DPDA) and prefractal dual printed dipole antenna (PF-DPDA) are used for bluetooth and WiMAX applications. In [7], it presented CPW-feed step slot antenna.…”

“…In addition to increasing the substrate thickness, the inductance can be increased, e.g., by a spiral structure [3] whereas the capacitive coupling can be increased with the fork [4] and interdigital [5] structures. As in antenna design [6], slots can be used to increase capacitive loading of the EBG patches. All these measures decrease the band width of the stop band.…”