1. Wong, Y. S., S. Y. Zheng, and W. S. Chan, "Multifolded bandwidth branch line coupler with filtering characteristic using coupled port feeding," Progress In Electromagnetics Research, Vol. 118, 17-35, 2011.
doi:10.2528/PIER11041401 Google Scholar
2. Zhu, J., Y. Zhou, and J. Liu, "Miniaturization of broadband 3-dB branch-line coupler," Progress In Electromagnetics Research Letters, Vol. 24, 169-176, 2011. Google Scholar
3. Meany, P., "A novel branch line coupler design for millimeterwave applications," IEEE MTT-S Int. Microwave Symp., Vol. 1, 585-588, 1990.
doi:10.1109/MWSYM.1990.99648 Google Scholar
4. Liao, S.-S., P.-T. Sun, and N.-C. Chin, "A novel compact-size branch-line coupler," IEEE Microwave and Wireless Components Letters, Vol. 15, No. 9, September 2005.
doi:10.1109/LMWC.2005.855377 Google Scholar
5. Jizat, N. M., S. K. A. Rahim, and T. A. Rahman, "Miniaturized size of dual-band-meandered branch-line coupler for WLAN application," Microwave and Optical Technology Letters, Vol. 53, No. 11, November 2011. Google Scholar
. Elhiwaris, M. Y. O. and S. K. A. Rahim, "Miniaturized size branch line coupler using open stubs with high-low impedances," Progress In Electromagnetics Research Letters, Vol. 23, 65-74, 2011. Google Scholar
7. Settaluri, R. K., G. Sundberg, A. Weisshaar, and V. K. Tripathi, "Compact folded line rat-race hybrid couplers," IEEE Trans. Microwave Theory Technology, Vol. 10, No. 2, 61-63, February 2000. Google Scholar
8. Nosrati, M. and S. K. Valashani, "A novel compact branch-line coupler using four coupled transmission lines," Microwave and Optical Technology Letters, Vol. 50, No. 6, June 2008.
doi:10.1002/mop.23460 Google Scholar
9. Chen, D.-Z., X.-W. Shi, Y.-Y. Yang, and F. Wei, "Compact microstrip parallel coupler with high isolation," Electronic Letters, Vol. 44, No. 12. Google Scholar
10. Fooks, E. H., Microwave Engineering Using Microstrip Circuits, Prentice Hall, New York, 1990.
11. Pozar, D. M., Microwave Engineering, 2nd Ed., Wiley, New York, 1998.