Vol. 58

Latest Volume
All Volumes
All Issues

Optically Transparent Compact 4×4 Butler Matrix for Wi-Fi Applications

By Ousama Abu Safia, Mourad Nedil, Mustapha Yagoub, and Walid Yusuf
Progress In Electromagnetics Research Letters, Vol. 58, 119-124, 2016


In this paper, an optically transparent (OT) compact 4×4 Butler matrix (BM) operating at 2.4 GHz for Wi-Fi applications is proposed. The device has structured grids refined in quadrilateral cell shapes. The dimensions of cells are chosen based on a simple formulawhich guarantees a minimum required transparency levelin conjunction with a limited rounds of optimizations. A theoretical optical transparency value of 76.2% has been obtained without affecting the excellent electrical performance of the BM. Moreover, complimentary square split ring resonators (CS-SRRs) are patterned in the ground plane of each transparent transmission line in the BM. This loading technique provides a relative size reduction of 16.6% compared to a conventional structure. Simulated and measured results of the proposed design agree well with conventional BM's results. The proposed technique and its related features can be expanded to other microwave devices.


Ousama Abu Safia, Mourad Nedil, Mustapha Yagoub, and Walid Yusuf, "Optically Transparent Compact 4×4 Butler Matrix for Wi-Fi Applications," Progress In Electromagnetics Research Letters, Vol. 58, 119-124, 2016.


    1. Tseng, C.-H., C.-J. Chen, and T.-H. Chu, "A low-cost 60-GHz switched-beam patch antenna array with butler matrix network," IEEE Antennas and Wireless Propagation Lett., Vol. 7, 432-435, 2008.

    2. Chang, C.-C., R.-H. Lee, and T.-Y. Shih, "Design of a beam switching/steering butler matrix for phased array system," IEEE Transactions on Antennas and Propagation, Vol. 58, No. 2, 367-374, Feb. 2010.

    3. Gandini, E., M. Ettorre, R. Sauleau, and A. Grbic, "A lumped-element unit cell for beam-forming networks and its application to a miniaturized butler matrix," IEEE Transactions on Microwave Theory and Techniques, Vol. 61, No. 4, 1477-1487, Apr. 2013.

    4. Bona, M., L. Manholm, J. P. Starski, and B. Svensson, "Low-loss compact Butler matrix for a microstrip antenna," IEEE Transactions on Microwave Theory and Techniques, Vol. 50, 2069-2075, Sept. 2002.

    5. Wang, C.-W., T.-G. Ma, and C.-F. Yang, "A new planar artificial transmission line and its applications to a miniaturized butler matrix," IEEE Transactions on Microwave Theory and Techniques, Vol. 55, No. 12, 2792-2801, Dec. 2007.

    6. Denidni, T. A. and T. E. Libar, "Wide band four-port butler matrix for switched multibeam antenna arrays," 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications 2003, PIMRC 2003, Vol. 3, 2461-2464, Sept. 7-10, 2003.

    7. Abu Safia, O., L. Talbi, and K. Hettak, "A new type of transmission line-based metamaterial resonator and its implementation in original applications," IEEE Trans. on Magnetics, Vol. 49, 968-973, Mar. 2013.

    8. Abu Safia, O., "Development of new types of transmission line-based metamaterial inclusions/cells and their applications,", doctoral dissertation, University of Quebec, Gatineau, QC, Canada, Sept. 2014.

    9. Hautcoeur, J., X. Castel, F. Colombel, R. Benzerga, M. Himdi, G. Legeay, and E. Motta Cruz, "Transparency and electrical properties of meshed metal films," Thin Solid Films, Vol. 519, 3851-3858, 2011.

    10. Hautcoeur, J., F. Colombel, X. Castel, M. Himdi, and E. Motta Cruz, "Optically transparent monopole antenna with high radiation efficiency manufactured with silver grid layer (AgGL)," Electronics Letters, Vol. 45, No. 20, 1014-1016, Sept. 2009.

    11. Lee, E. N., R. Hall, G. Katulka, K. Duncan, E. Barry, P. Pa, M. Mirotznick, P. Patel, and L. Holmes, "Modeling, simulation, and measurement of a transparent armor embedded meshed microstrip antenna," 2012 IEEE Antennas and Propagation Society International Symposium (APSURSI), 1-2, Jul. 8-14, 2012.

    12. Hautcoeur, J., L. Talbi, K. Hettak, and M. Nedil, "60 GHz optically transparent microstrip antenna made of meshed AuGL material," IET Microwaves, Antennas & Propagation, Vol. 8, 1091-1096, Oct. 2014.

    13. Colombel, F., X. Castel, M. Himdi, G. Legeay, S. Vigneron, and E. M. Cruz, "Ultrathin metal layer, ITO film and ITO/Cu/ITO multilayer towards transparent antenna," IET Sci., Meas. Technol., Vol. 3, No. 3, 229-234, May 2009.

    14. Saha, C., J. Y. Siddiqui, and Y. M. M. Antar, "Square split ring resonator backed coplanar waveguide for filter applications," 2011 XXXth URSI General Assembly and Scientific Symposium, 1-4, Aug. 13-20, 2011.