Dual‐band SICL branch‐line coupler

A dual-band substrate integrated coaxial line (SICL) 3-dB branch-line coupler and its compact realization are proposed in this letter. The SICL coupler with the compact structure shows a comparable performance and great size reduction compared with the conventional structure. The simulated and measured results match very well. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1246–1249, 2015