3D Printed Periodic Structures for Subterahertz SourcesD. I. Sobolev, M.D. Proyavin, N.Yu. Peskov, V.Yu. Zaslavsky and V.V. ParshinEPJ Web Conf., 195 (2018) 01017DOI: https://doi.org/10.1051/epjconf/201819501017