Reduced Nonlinearity Superconducting Thin Films for Transmit and Receive Applications

This STTR Phase II project is directed towards the development of high performance large-area thick YBCO films and microwave devices on suitable single crystal substrates through modified TFA-MOD approach for transmit and receive applications. We propose to continue our successful Phase I project to further increase critical current density of Jc to 3-5 MA/cm2 and lead to state-of-the-art IMD (intermodulation distortion) by improving linearity, reducing surface resistance and increasing power handling capability of YBCO films. Effort will be toward deposition of high performance YBCO films on large crystal wafers with thickness up to 2-3 microns by modified TFA-MOD process through multiple coating, pyrolysis, and crystallization. To achieve these goals, layered growth mode is suggested and will be pursued by the control of driving force and saturation of precursor. The UES method would make film fabrication much cheaper, highly reproducible, and easy to scale up. With the successful growth of high performance thick YBCO films, stripline resonator will be designed and measured by the UES-MIT team. The process will be scaled up to make large area thick YBCO films for fabricating large arrays of microwave filters for the transmit and receive applications for both military and civilian applications.