| The increasing demands for higher performance electronic circuits in both digital and analog applications is leading to the development and implementation of alternative technologies. One area of interest is the operation of circuits and subsystems at cryogenic temperatures to improve their speed, reliability, and power handling requirements. Semiconductor devices for microwave applications such as the high electron mobility transistor (HEMT) exhibit superior performance at lower temperatures due to improved transmission gain, noise figure, and frequency of operation.;Superconductivity is a promising alternative for improving circuit performance. The recent discovery of high temperature superconductors (HTSCs) which operate above the temperature of liquid nitrogen (77K) has made its application in analog and digital electronics much more feasible. Previous low temperature superconductors, requiring expensive cooling systems, have demonstrated superior performance to conventional circuits in terms of speed, sensitivity, and switching capability. The extremely low loss properties of HTSCs, along with the simpler refrigeration systems necessary for operation, allow high Q resonators to be used in microwave components such as narrowband filters and low phase-noise oscillators.;This thesis presents the design and performance of a hybrid semiconductor/superconductor K-band filter/amplifier microwave integrated circuit. The circuit combines the high frequency, high performance advantages of a cryogenically cooled GaAs HEMT with the low loss, high Q properties of a narrowband HTSC filter and matching networks. |
