Table of Contents
International Journal of Microwave Science and Technology
Volume 2008, Article ID 784526, 7 pages
Research Article

A New Design of Compact 𝟒 × 𝟒 Butler Matrix for ISM Applications

1Laboratory of Electronic, Faculty of Sciences of Tunis, Tunis El Manar University, 2092 Tunis, Tunisia
2Laboratoire de Recherche Télébec en Communications Souterraines LRTCS 450, 3e Avenue, Local 103 Val-d'Or (Québec), Canada J9P 1S2
3INRS-EMT, Université de Québec, Place Bonaventure 800, de la Gauchtière Ouest West, Suite 6900, Montréal, QC, Canada H5A 1K6

Received 5 May 2008; Revised 9 September 2008; Accepted 22 December 2008

Academic Editor: Kenjiro Nishikawa

Copyright © 2008 Mbarek Traii et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A novel design of a compact 4 × 4 Butler matrix is presented. All the design is based on the use of a Lange coupler with certain geometrical characteristics. This matrix occupies only 20% of the size of the conventional Butler matrix at the same frequency (80% of compactness). To examine the performance of the proposed matrix, the Lange coupler and the Butler matrix were simulated using Momentum (ADS) and IE3D softwares. Simulation results of magnitude and phase show a good performance. Furthermore, a four-antenna array was also designed at 2.45 GHz and then connected to the matrix to form a beamforming antenna system. As a result, four orthogonal beams at 4 5 , 1 5 , 1 5 , and 4 5 are produced. This matrix is suitable for wireless application at ISM band of 2.45 GHz.