Characteristics of Josephson junctions obtained by the focused ion beam method in YBCO/CeO$_2$/Al$_2$O$_3$

HTS Josephson junctions were made on a sapphire substrate with a sublayer of epitaxial cerium oxide using a focused beam of helium ions. The transport and microwave properties of junctions obtained at different radiation doses of YBa$_2$Cu$_3$O$_{7-d}$ bridges have been studied. When exposed to the studied Josephson junctions of radiation with a frequency of about 79 GHz, Shapiro steps are observed on their current-voltage characteristics.