Ramp-type junctions connecting the d-wave superconductor YBazCu307.s and the s-wave superconductor niobium are fabricated using a thin gold layer as a chemical barrier. High critical current densities exceeding 5 kA/cm2 are obtained. The normal state resistivity (R,& values of the junctions are of the order of 0.1 pQ cm'. The magnetic field behavior of the critical current of junctions oriented in the [lOC]- and in the [Ill!]-direction of the YBazCu307.sis explained in terms of a predominant dxz.yz order parameter in the high-T, superconductor.