volume | PIER Journals

Abstract

This paper presents a novel design of miniaturized microstrip quadrature coupler at 2.45 GHz. The design topology is based on reduced transmission line branch arms using recursively loaded stubs that contribute to the compact size. The proposed coupler result in a size reduction of 70.4% when compared to a conventional branch line hybrid. The designed coupler provides, at the operating frequency, a 25 dB isolation and exhibits equal power division at the output ports with quadrature phase difference. A fabricated prototype is developed with simulation and measurement in close agreement.

1. Pozar, D. M., Microwave Engineering, 3rd edition, New York, Wiley, 2005.
doi:10.1109/13.53636

2. Fooks, E. H. and R. A. Zakarevicius, Microwave Engineering Using Microwave Circuits, Prentice Hall, New York, 1990.

3. Ghali, H. and T. A. Moselhy, "Miniaturized fractal rat-race, branch-line, and coupled-line hybrids," IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 11, 2513-2520, Nov. 2004.
doi:10.1109/TMTT.2004.837154 Google Scholar

4. Sun, K. O., S. J. Ho, C. C. Yen, and D. Weide, "A compact branch-line coupler using discontinuous microstrip lines," IEEE Microwave and Wireless Technology Letters, Vol. 15, No. 8, 519-520, 2005.
doi:10.1109/LMWC.2005.852789 Google Scholar

5. Liao, S. S., P. T. Sun, N. C. Chin, and J. T. Peng, "A novel compact size branch-line coupler," IEEE Microwave and Wireless Technology Letters, Vol. 15, No. 9, 588-590, Sep. 2005.
doi:10.1109/LMWC.2005.855378 Google Scholar

6. Tang, C. W. and M. G. Chen, "Synthesizing microstrip branch line couplers with predetermined compact size and bandwidth," IEEE Transactions on Microwave Theory and Techniques, Vol. 55, No. 9, 1926-1934, 2007.
doi:10.1109/TMTT.2007.904331 Google Scholar

7. Jung, S.-C., R. Negra, and F. M. Ghannouchi, "A design methodology for miniaturized 3-dB branch-line hybrid couplers using distributed capacitors printed in the inner area," IEEE Transactions on Microwave Theory and Techniques, Vol. 56, No. 12, 2950-2953, 2008.
doi:10.1109/TMTT.2008.2007323 Google Scholar

8. Tseng, C. H. and C. L. Chang, "A rigorous design methodology for compact planar branchline and rat-race couplers with asymmetrical T structures," IEEE Transactions on Microwave Theory and Techniques, Vol. 60, 2085-2092, Jul. 2012. Google Scholar

9. Elhiwaris, M. Y. O., S. K. A. Rahim, U. A. K. Okonkwo, and N. M. Jizat, "Miniaturize size branch line coupler using open stubs with high low impedances," Progress In Electromagnetic Research Letters, Vol. 23, 65-74, Apr. 2011. Google Scholar

10. Sun, L., Y. Z. Yin, X. Lei, and V. Wong, "A novel miniaturized branch line coupler with equivalent transmission Lines," Progress In Electromagnetics Research Letters, Vol. 38, 35-44, 2013. Google Scholar

11. Al-Khateeb, L., "Miniaturized hybrid branch line couplers based on a square split resonator loading technique," Progress In Electromagnetics Research Letters, Vol. 40, 153-162, 2013. Google Scholar

12. , , Users Manual, CST Microwave studio 2010.

Prof. Rowdra Ghatak

Dr. Manimala Pal

Mr. Biswajit Sarkar