Comments on "Hollow Image Guide and Overlayed Image Guide Coupler"

The authors of the above paper failed to acknowledge several publications dedicated to the same subject. The so-called hollow image guide has already been studied by the E.D.C. method with the name of pi guide, as well as another dielectric structure named T guide [2]. The same paper shows a good agreement between the theoretical and the experimental results which were measured by means of a movable electric field probe with the end of the dielectric waveguides finished in a short circuit.