HIGH-TEMPERATURE SUPERCONDUCTING COPLANAR AND EPITAXIALLY GROWN MICROSTRIP TRANSMISSION-LINES STUDIED BY A HALF-WAVELENGTH RESONATOR TECHNIQUE

Coplanar YBa2Cu3O7-x (YBCO) thin film and epitaxial YBCO/NDAIO(3)/YBCO microstrip transmission lines were investigated using planar half wav elength resonators. The results were compared to theoretical calculati ons. Coplanar transmission lines in coplanar waveguide and coplanar st ripline geometries exhibited unloaded quality factors up to 2600 and a ttenuation constants down to 0.6 dB/m at 77 k and at frequencies of 5. 5 GHz. These results are two orders of magnitude below normal metal li nes. Planar microstrip resonators which were epitaxially grown by comb ined d.c./r.f. sputtering showed attenuation constants down to 26 dB/m at 50 k at 4.7 GHz. The results achieved with the microstrip lines re quire a further technological development in order to be improved whil e they are already significantly below normal metal based lines. These results are already promising with respect to a use as transmission l ines in integrated circuits.