A compact 3-db directional coupler using dual transmission lines on dual substrate layer for butler matrix application

In this paper, A compact 3-dB directional coupler using dual transmission lines on dual substrate layer is presented. The proposed coupler comprises of two conductor layer at top and bottom substrates. These two conductors are coupled through a circular aperture in the common ground plane. The simulated proposed coupler is designed using CST Microwave Studio 2010 by using inexpensive FR-4 substrate to operate at 2.45 GHz. The design is able to provide a good size and bandwidth simultaneously, which is not offered by any recent reported structures, i.e., size reduction of 60 % with a simultaneous bandwidth achieved up to 48 %.

[1]  S. K. A. Rahim,et al.  Beamforming networks using reduced size and Cascaded Butler Matrices , 2010, Proceedings of the Fourth European Conference on Antennas and Propagation.

[2]  Tayeb A. Denidni,et al.  A New Ultra-Wideband Beamforming for Wireless Communications in Underground Mines , 2008 .

[3]  Constantine A. Balanis,et al.  Antenna Theory: Analysis and Design , 1982 .

[4]  J. A. Garćıa.  A Wide-Band Quadrature Hybrid Coupler (Correspondence) , 1971 .

[5]  A. Hazeri,et al.  Design and analyze of a highly compact directional coupler based on microwave planar circuit , 2009, 2009 Asia Pacific Microwave Conference.

[6]  D. Pozar.  Microwave Engineering , 1990 .

[7]  F.M. Ghannouchi,et al.  A Design Methodology for Miniaturized 3-dB Branch-Line Hybrid Couplers Using Distributed Capacitors Printed in the Inner Area , 2008, IEEE Transactions on Microwave Theory and Techniques.

[8]  Jau-Horng Chen,et al.  A miniaturized branch-line coupler using finger-shape distributed capacitors , 2010, 2010 Asia-Pacific Microwave Conference.

[9]  Tayeb A. Denidni,et al.  ANALYSIS AND DESIGN OF AN ULTRA WIDEBAND DIRECTIONAL COUPLER , 2008 .

[10]  Chi-Hsueh Wang,et al.  A compact LTCC branch-line coupler UsingModified-T equivalent-circuit modelfor transmission line , 2006 .

[11]  Tayeb A. Denidni,et al.  Design of a broadband multilayer coupler for UWB beamforming applications , 2011, 2011 41st European Microwave Conference.

[12]  M.E. Bialkowski,et al.  Design of Compact Directional Couplers for UWB Applications , 2007, IEEE Transactions on Microwave Theory and Techniques.

[13]  Qiaoli Zhang,et al.  Compact Broadside Coupled Directional Coupler Based on Coplanar CRLH Waveguides , 2009 .

[14]  F. Hosseini,et al.  Novel compact branch-line coupler using non-uniform transmission line , 2009, 2009 Asia Pacific Microwave Conference.

[15]  Yo-Shen Lin,et al.  A compact LTCC branch-line coupler UsingModified-T equivalent-circuit modelfor transmission line , 2006, IEEE Microwave and Wireless Components Letters.

[16]  Ching-Wen Tang,et al.  Miniaturization of Microstrip Branch-Line Coupler With Dual Transmission Lines , 2008, IEEE Microwave and Wireless Components Letters.

[17]  Wei Hong,et al.  A double layer crossed over Substrate Integrated Waveguide wide band directional coupler , 2008, 2008 Asia-Pacific Microwave Conference.

[18]  N. Seman,et al.  A 45° phase shifter in microstrip-slot technology for beam forming network application , 2012, 2012 IEEE Symposium on Wireless Technology and Applications (ISWTA).

[19]  Mohd Faizal Jamlos,et al.  MINIATURIZED SIZE BRANCH LINE COUPLER USING OPEN STUBS WITH HIGH-LOW IMPEDANCES , 2011 .

[20]  M. Aikawa,et al.  New slot-coupled directional couplers between double-sided substrate microstrip lines, and their applications , 1988, 1988., IEEE MTT-S International Microwave Symposium Digest.

[21]  N. Seman,et al.  Design of compact single-section directional coupler for butler matrix beam-forming MIMO , 2011, 2011 XXXth URSI General Assembly and Scientific Symposium.

[22]  Sharul Kamal Abdul Rahim,et al.  Dual butler matrix active antenna system , 2007 .

[23]  F. D. Ronde.  A New Class of Microstrip Directional Couplers , 1970 .