Reduced Nonlinearity Superconducting Thin Films for Transmit and Receive Applications

Superconductor Technologies Inc. (STI) is the worldwide leader in the manufacture of high-temperature superconductor (HTS) receive filter systems for commercial and military applications. STI has deployed nearly 6,000 such filter systems having a cumulative run time of over 165 million hours and an MTBF of over 500,000 hours. STI¡¦s highly selective and sensitive RF filters are fabricated from HTS thin films that are deposited by reactive coevaporation (RCE). STI has developed proprietary RCE vacuum deposition systems for high-volume manufacturing of such wafers. The primary Phase 2 objective is to determine whether thicker YBCO films produced by RCE can possess reduced nonlinearities compared with STI¡¦s state-of-the-art standard-thickness films. We will grow and measure thick single-layer and multilayer YBCO films on both MgO and LaAlO3 substrates. We will optimize the growth of these films to as great a thickness as possible while maintaining excellent crystallinity and RF properties. Additionally we will develop procedures for optimal thicker-film fabrication of filter circuits. We will perform RF testing including intermodulation distortion (IMD) measurements and will provide films to MIT/Lincoln Laboratory for complementary RF testing.