Amorphous Fluoropolymer Films for Superconductive Microwave Components Using High-Tc Superconducting Films

This paper describes the influence of amorphous fluoropolymer (AF) film on the properties of high-T c superconductive microwave components, when it is used for surface protection and as a spacer. It is found that AF film can protect EuBaCuO and TlBaCaCuO superconducting film from dampness, thus maintaining the properties of a microstrip resonator for at least 1000 h. The AF protection has almost no effect on properties such as temperature dependence and unloaded-Q values in high-Q microwave components. Additionally, the use of AF film as a spacer in a strip-line structure reduces the influence of spacing on the effective dielectric constant and characteristic impedance.