We have fabricated YBa2Cu3O7−&dgr;/PrBa2Cu3O7−&dgr;/YBa2Cu3O7−&dgr;ramp‐type Josephson junctions with high characteristic voltageVc=IcRnat a temperature of 77 K. A microshadow mask technique was used to grow completelyinsitua ramp‐type multilayer structure. Junctions with barrier thicknesses of about 13 and 45 nm were characterized. Junctions with a thicker barrier exhibited supercurrent up to 80 K and showed a resistively shunted‐junction‐like current voltage characteristics with aVcas high as ∼1.5 mV at 77 K and 16 mV at 15 K. Junctions with a thinner barrier worked up to 90 K and exhibited the ac Josephson effect at 77 K under 8.9 GHz microwave radiation. ©1996 American Institute of Physics.