Academic journal article American Academic & Scholarly Research Journal

Adaptive Elliptical Patch Antenna Array for WLAN: A Smart Approach to Beam Switching through Phase Shifting in Feed Network Using Elliptical Patch Array for Dual Band

Academic journal article American Academic & Scholarly Research Journal

Adaptive Elliptical Patch Antenna Array for WLAN: A Smart Approach to Beam Switching through Phase Shifting in Feed Network Using Elliptical Patch Array for Dual Band

Article excerpt

Abstract. The WLAN is operated in some high traffic area where the radiation beam produced by the elliptical patch antenna is to be utilized with optimum efficiency. The aim of the antenna array is to produce some directive and switched beams rather than producing omni-directional pattern which cover 360°, can be considered to be wastage in some non-used or low traffic areas. Hence, directive beam and switching it without actually changing the direction of the elliptical patch array is a smart way for WLAN application . A smart antenna array system performs the adaptive beam forming by focusing the beam in the desired direction and creating nulls in other directions to avoid the interference and the wasting of the beams. This is performed by the operating the phase shifting in its feed network and different ports. This paper investigates the performance of the elliptical patch array patterns operating in dual bands with different phase shifting for the optimum performance of the WLAN applications.

Keywords: Beam forming, array, adaptive antenna, WLAN, elliptical patch.

I. INTRODUCTION

In this era of high evolution in communication technology, the WLAN has become intensively popular for the various purposes such as personal area networking, the high speed internet, the video streaming, multimedia and so on. For the dramatic change of the demand of wireless access in the indoor environment, WLAN has become a big issue considering its performance and efficiency. Therefore, to ensure the high data rate and the effective use of the network, the compensation of the multipath effects and the co-channel interference have grown to be a matter of great interest. In addition, the high gain and the high coverage of the WLAN to a desired direction of high traffic with reducing the dead spot in an indoor environment also became a high priority for the researchers.

In earlier version of WLAN, the simple dipole antenna is used which exhibits Omni- directional pattern which means the signal is scattered to all direction with low gain and efficiency and hence the users with high quality signal achieve the small percentage of the signal compared to their demand while the signal is wasted in other areas with low demand. Even boosting the radiation of this antenna, the performance cannot be improved, as the signal being boosted to all directions.

The smart antenna array enhances the radiation efficiency by producing the distributed current throughout the whole area. This distributed current produces the directive beams and narrow or pencil beam and those directive beams can be switched towards the desired direction by using the phase shifting technique in its feed network (Balanis, 1997).

In this paper, the elliptical patch antenna array is designed with typical micro-strip patch antenna for its compactness and simplicity as the research aims at the compact and low cost design for the WLAN application (Balanis, 1997). Considering the array, the multiple elements can be mounted on the same plane which increases the compactness in terms of thickness of the antenna system for the WLAN. This design does not require any LINC (Linear amplifications with Non-linear Components) Power Amplifier, hence, no risk of imbalance of the gain when practically implemented (Lee & Ng, 2005) Due to simple feed network even with increasing elements, this design is not limited to a 4X4 Butler matrix (Pham, Lee, & Flaviis, undated) . In this work a simple planar array which exhibits a wide range of switching options and that eliminates the requirement of a complicated network such as a hexagonal 7 element array (Akkermans & Herben ,2007 ).

II. WIRELESS LAN

The whole WLAN topology can be divided into two basic parts: the AP and the clients. The access point act as the radio transceiver between the other devices those are enabled with WLAN. The AP can be compared with the base station (BS) of a cellular network which is the radio interface for the whole network ( Alvarion website 2009). …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.