Comments on "W-Band Multiport Substrate-Integrated Waveguide Circuits

The paper by Moldovan presents simulated and measured data on "new" circuit structures based on the substrate-integrated waveguide transmission line. The sometimes significant difference between measured and simulated data is broadly attributed to "fabrication error," and in some cases, the measured data does not account for all of the signal energy. It is also unclear as to what aspects of the presented work are different from previously reported structures by the authors