A simple 2×3 reconfigurable beam-forming network (R-BFN) for four-beam reconfiguration application is designed and implemented. The proposed R-BFN with two input ports and three output ports consists of a 2:1 power divider, a 90° hybrid, a 180° hybrid and a 2-bit phase shifter. The 2-bit phase shifter has two states: one is a 180° phase shifter (State 1); the other is a 0°/360° phase shifter (State 2). By introducing the 2-bit phase shifter, the constant phase differences of three output ports can be reconfigured. Specifically, as different input ports are excited, the R-BFN provides three output signals with equal power levels and the progressive phases of -120° and 120° when the 2-bit phase shifter at state 1, while -60° and 60° when the 2-bit phase shifter at state 2, respectively. When the proposed R-BFN is connected to an antenna array, a four-beam reconfiguration is obtained. Simulated and measured results show that good impedance matching, high port isolation, equal power division, and constant phase difference have been achieved simultaneously within the operation band of 2.4-2.6 GHz. The capability of the proposed R-BFN to reconfigure beams is also verified experimentally by using a 2.5 GHz dipole array.
2. Stutzman, W. L. and G. A. Thiele, Antenna Theory and Design, 2nd Ed., Wiley, New York, 1997.
3. Skolnik, M., Radar Handbook, 2nd Ed., McGraw-Hill, New York, 1990.
4. Parker, D. and D. C. Zimmerman, "Phased arrays - Part I: Theory and architectures," IEEE Trans. Microw. Theory Techn., Vol. 50, No. 3, 678-687, Mar. 2002.
doi:10.1109/22.989953
5. Parker, D. and D. C. Zimmerman, "Phased arrays - Part II: Implementations, applications, future trends," IEEE Trans. Microw. Theory Techn., Vol. 50, No. 3, 688-698, Mar. 2002.
doi:10.1109/22.989954
6. Butler, J. and R. Lowe, "Beam-forming matrix simplifies design of electronically scanned antennas," IEEE Trans. Electron. Devices, 170-173, 1961.
7. Xu, H.-X., G.-M. Wang, and X. Wang, "Compact Butler matrix using composite right/left handed transmission line," Electron. Lett., Vol. 47, No. 19, 1081-1082, Sep. 2011.
doi:10.1049/el.2011.2135
8. Nedil, M., T. A. Denidni, and L. Talbi, "Novel Butler matrix using CPW multilayer technology," IEEE Trans. Microw. Theory Techn., Vol. 54, No. 1, 499-507, Jan. 2006.
doi:10.1109/TMTT.2005.860490
9. 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 Wireless Propag. Lett., Vol. 7, 432-435, 2008.
doi:10.1109/LAWP.2008.2001849
10. Blass, J., "Multi-directional antenna: New approach top stacked beams," IRE Int. Convention Record, 48-50, Pt. 1, 1960.
11. Chen, P., W. Hong, Z. Kuai, and J. Xu, "A double layer substrate integrated waveguide blass matrix for beamforming applications," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 6, 374-376, 2009.
doi:10.1109/LMWC.2009.2020020
12. Nolen, J., "Synthesis of multiple beam networks for arbitrary illuminations,", Ph.D. Dissertation, Bendix Corporation, Radio Division, Baltimore, MD, Apr. 1965.
13. Djerafi, T., N. J. G. Fonseca, and K. Wu, "Planar Ku-band 4×4 Nolen matrix in SIW technology," IEEE Trans. Microw. Theory Techn., Vol. 58, No. 2, 259-266, Feb. 2010.
doi:10.1109/TMTT.2009.2037866
14. Rappaport, T. D., Wireless Communication System, 2nd Ed., John Wiley & Sons Inc., 2001.