A metal 3D-printed T-junction OMT with an offset stepped post

We propose a T-junction OMT consists of an offset stepped post. The offset stepped post contributes to the matching of two rectangular ports at the short circuit situated at opposed side walls. The structure without conventional ridges is simple and makes it possible to achieve robust performances. We fabricated a proposed T-junction OMT in a single piece of an aluminum alloy, using a commercial metal 3D-printer. The proposed simple and compact structure with robust performances is considered to overcome disadvantage of 3D-printer, such as fabrication tolerance and surface roughness. The measured results demonstrated a return loss of 22dB and a loss of 0.3dB with a bandwidth of 8% in the K-band.