In this paper, a coupled-line based dual-band branch-line coupler with port-extensions is presented. The configuration of the coupler consists of a single coupled-lines section, two transmission lines, and an easy to analyze L-section impedance matching network at all four ports of the coupler. A detailed theoretical analysis is carried out to obtain the closed-form design equations to determine the design parameters of the coupling structure. It is observed that the proposed dual-band coupler can support wide band-ratio and arbitrary power division. To validate the proposed design concept, a prototype working at 0.9 GHz and 1.8 GHz is fabricated on a 60 mil Rogers 4003C substrate exhibiting excellent match between the simulated and measured results.
Asif Iftekhar Omi,
Mohammad A. Maktoomi,
Praveen Kumar Sekhar,
"A New Coupled-Line Based Dual-Band Branch-Line Coupler with Port-Extensions," Progress In Electromagnetics Research M,
Vol. 105, 21-30, 2021. doi:10.2528/PIERM21081203
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