Influence of weak reflection from a nonresonant load on the operation frequency of the 28 GHz technological gyrotronA.A. Bogdashov, G.G. Denisov, A.P. Fokin, M.Yu. Glyavin, Yu.V. Novozhilova, A.S. Sedov and A.I. TsvetkovEPJ Web Conf., 149 (2017) 04037DOI: https://doi.org/10.1051/epjconf/201714904037