A method for matching high-temperature superconductor resonators used for NMR signal pickup at 400 MHz

This paper describes a method for matching high-temperature superconducting nuclear magnetic resonance (NMR) signal pickup coils to field-effect transistor (FET) preamplifiers using amplifier-specific noise figure and gain parameters to obtain a matching compromise that improves gain flatness for a given permissible noise figure. A technique for obtaining these parameters is also described in an appendix.