Single‐layer standalone wideband substrate‐integrated waveguide directional coupler

The design and characterization of a single-layer wideband substrate integrated waveguide 3-dB standalone directional coupler are described. The device exhibits a bandwidth of 2 GHz, ranging from 10.7 to 12.7 GHz, and both return loss and isolation better than 15 dB. The coupler has been built using a TACONIC RF-35 A2 substrate. A very good agreement between simulations and experimental results is obtained. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1141–1144, 2014