Beam forming networks using reduced size butler matrix

• Main Authors: Abd. Rahim, Sharul Kamal, Jizat, N. M., Sabran, M. I.
• Format: Article
• Published: Kluwer Academic Publishers 2010
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utm.my/id/eprint/22878/; http://dx.doi.org/10.1007/s11277-010-0164-8
• Institution: Universiti Teknologi Malaysia

Beam forming vector are calculated to track and locate the antenna beam on the target are becoming popular demand to cope with the growing demand for supportable peak data rates, coverage requirements, and capacity objectives, as well as exciting new and enhanced applications. The system provides a broad range of ways to improve the performance of wireless communication systems, thus characterized as some of the most promising devices in wireless communications. While this revolution is significantly expanding the opportunity for new, smaller and better wireless communication terminals, it also is creating new performance demands for antennas. The implementation of beamforming network as one of smart antenna medium in future wireless systems is anticipated to have a significant impact on the efficient use of the spectrum, the minimization of the cost of establishing new wireless networks, the optimization of service quality, and recognized of transparent operation across multi technology wireless networks. Furthermore, smart antennas improve call quality on both forward and reverse links. Thus, reduced- size cascaded Butler matrices are developed for dual-band and dual-beam applications are presented in this paper using meander-line technique, an acceptable approach for reducing the size of the radio frequency element. Compared with the conventional size, the proposed branch-line coupler (BLC) were reduced in size by 63 % and 56 % at 2.45 GHz and 5.8 GHz, respectively. The proposed, cascaded Butler matrices have the ability to exhibit two types of beams, i.e., narrow and broad, by feeding the signal into the respective input port of the Butler matrix. A meander line branch-line coupler with an area of 96 mm × 125 mm was used to replace the conventional, straight transmission line. This reduced the area of the Butler matrix by 36% compared to the conventional matrix. The actual measurements showed very good agreement with the results obtained from simulations.