We report the experimental results on the investigation of superconducting double-barrier structures with niobium interlayer and Al 2 O 3 barriers. ... Proceedings of the Third European Conference on Applied Superconductivity (EUCAS’97), Twente, The Netherlands, Inst. ... Ramp-type Josephson junctions with YBCO superconducting electrodes and PrBa 2 Cu 2.6 O 6+ ? ... A technology for fabrication of YBCO ramp junctions on a superconducting ground plane is developed and evaluated. ... 769 (2001) . ...