A novel ultra-wideband (UWB) coupled-line coupler with an operating frequency band from 2 to 22 GHz is presented in this article. The proposed coupler is composed of six coupled-line sections. The continuous zigzag capacitive compensation (CZCC) technology is used to broaden the operation frequency band, which also significantly enhances the isolation and return losses of the coupler. The coupler is built on a multilayer circuit structure. In order to improve the design accuracy of the three-dimensional circuit structure, the combination simulation of EM simulator and circuit simulator are employed. The simulated and measured results of the UWB 10 dB asymmetric directional coupler are presented and discussed, which demonstrate that it is practical to achieve good performances in such a circuit structure.
2. Cristal, E. G. and L. Young, "Theory and tables of optimum symmetrical TEM-mode coupled-transmission-line directional couplers," IEEE Trans. Microwave Theory and Tech., Vol. 13, 544-558, Sep. 1965.
doi:10.1109/TMTT.1965.1126050
3. Levy, R., "Tables for asymmetric multi-element coupled-transmission-line directional couplers," IEEE Trans. Microwave Theory and Tech., Vol. 12, 275-279, May 1964.
doi:10.1109/TMTT.1964.1125809
4. Gruszczynski, S. and K. Wincza, "Broadband multisection asymmetric 8.34-dB directional coupler with improved directivity," Proc. Asia-Pacific Microw. Conf., 1-4, Bangkok, Thailand, Dec. 2007.
5. Uysal, S. and A. H. Aghvami, "Synthesis and design of wideband symmetrical nonuniform directional couplers for MIC applications," IEEE MTT-S Int. Microw. Symp. Dig., 587-590, 1988.
6. Sheleg, B. and B. E. Spielman, "Broad-band directional couplers using microstrip with dielectric overlays," IEEE Trans. Microwave Theory and Tech., Vol. 22, 1216-122, Dec. 1974.
doi:10.1109/TMTT.1974.1128466
7. March, S. L., "Phase velocity compensation in parallel-coupled microstrip," IEEE MTT-S Int. Microw. Symp. Dig., 410-412, 1982.
doi:10.1109/MWSYM.1982.1130739
8. Podell, A. F., "A high directivity microstrip coupler technique," G-MTT Int. Microwave Symposium Dig., 33-36, 1970.
9. Cristal, E. G. and L. Young, "Theory and tables of optimum symmetrical TEM-mode coupled transmission-line directional couplers," IEEE Trans. Microwave Theory and Tech., Vol. 13, 544-558, 1965.
doi:10.1109/TMTT.1965.1126050
10. Uysal, S. and A. H. Aghvami, "Synthesis, design and construction of ultra-wide-band nonuniform quadrature directional couplers in inhomogeneous media," IEEE Trans. Microwave Theory and Tech., Vol. 37, 969-976, 1989.
doi:10.1109/22.25398
11. Aharoni, O., K. Garb, and R. Kastner, "An ultra wideband, high directivity 3 dB coupler," 2014 44th European Microwave Conference (EuMC), 2014.
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