Modelling and investigation of HTS planar resonators and filters on sapphire substrate

A semi-empirical model is developed for high-Tc superconducting (HTS) planar transmission lines on anisotropic sapphire substrates. The model takes into account the anisotropic dielectric permittivity of sapphire and its temperature dependence. A CAD tool is developed for a simulation of HTS transmission line propagation characteristics. The contribution of the HTS film surface impedance to the line propagation parameters is considered in linear and nonlinear approaches. The model is verified by the experimental investigation of a half-wavelength resonator. The model is developed for a multicoupled line structure and applied to a multi-pole filter design. Eight-pole pseudo-interdigital filters based on YBCO films on r-cut sapphires substrate with a golden ground plane have been designed, manufactured and measured. The results confirm a prospective application of YBCO films on sapphire substrates in microwave electronics.

[1]  Irina Vendik,et al.  The phenomenological model of the microwave surface impedance of high‐temperature superconducting films with minimized number of fitting parameters , 1997 .

[2]  Irina Vendik,et al.  Model of high‐temperature superconducting coupled microstrip lines on anisotropic sapphire substrate , 1998 .

[3]  B. Utz,et al.  Double sided YBCO films on 4" substrates by thermal reactive evaporation , 1995, IEEE Transactions on Applied Superconductivity.

[4]  I. Vendik,et al.  Nonlinearity of superconducting transmission line and microstrip resonator , 1997 .

[5]  U. Poppe,et al.  Microwave surface resistance of epitaxial YBa2Cu3O7 thin films at 18.7 GHz measured by a dielectric resonator technique , 1992 .

[6]  R. S. Withers,et al.  Full-wave analysis of superconducting microstrip lines on anisotropic substrates using equivalent surface impedance , 1993 .

[7]  H. Chaloupka,et al.  Planar HTS structures for high-power applications in communication systems , 1997 .

[8]  R. Wördenweber,et al.  Growth of high‐quality YBa2Cu3O7−x films on CeO2 buffer of mixed (001)/(111) orientation on sapphire , 1995 .

[9]  Jerzy Krupka,et al.  Dielectric properties of single crystals of Al/sub 2/O/sub 3/, LaAlO/sub 3/, NdGaO/sub 3/, SrTiO/sub 3/, and MgO at cryogenic temperatures , 1994 .

[10]  T. Kaiser,et al.  Large-Area YBa2Cu3O7 − x Films on Sapphire with Excellent Microwave Power Handling Capability , 1998 .

[11]  Orest Vendik,et al.  Substrates for high-Tc superconductor microwave integrated circuits , 1994 .

[12]  Irina Vendik,et al.  A CAD model for microstrips on r‐cut sapphire substrates , 1994 .

[13]  Irina Vendik,et al.  Empirical model of the microwave properties of high-temperature superconductors , 1998 .

[14]  D. Bourse,et al.  MODELLING OF HIGH TC SUPERCONDUCTOR MICROSTRIP RESONATOR ON SAPPHIRE SUBSTRATE , 1996 .

[15]  R. Kutzner,et al.  Microwave losses and structural properties of large-area YBa/sub 2/Cu/sub 3/O/sub 7/ films on r-cut sapphire buffered with [001]/(111) oriented CeO/sub 2/ , 1997, IEEE Transactions on Applied Superconductivity.

[16]  Daniel E. Oates,et al.  Measurements and modeling of linear and nonlinear effects in striplines , 1992 .