Abstract: A radio frequency (RF) power amplifying system. The power amplifying system includes a power controller and power amplifiers comprising power transistors and bias circuitry. The bias circuitry provides current to the base of the one or more power transistors in such as manner as to automatically maintain the power transistors in substantially linear operation throughout the variation in voltage as supplied by the power controller.

Abstract: A radio frequency (RF) power amplifying system. The power amplifying system includes a power controller and power amplifiers comprising power transistors and bias circuitry. The bias circuitry provides current to the base of the one or more power transistors in such as manner as to automatically maintain the power transistors in substantially linear operation throughout the variation in voltage as supplied by the power controller.

Abstract: A temperature controlled cryogenic package system for efficiently and precisely monitoring and controlling the operating temperature of a high temperature superconductor circuit placed on a substrate. The cryogenic package system comprises a heating element formed on the same substrate as the high temperature superconductor circuit, a control circuit capable of activating and deactivating the heating element, and a temperature sensor placed in thermal proximity to the high temperature superconductor circuit. The temperature sensor monitors the operating temperature of the high temperature superconductor circuit, and conveys temperature information to the control circuit. The control circuit activates or deactivates the heating element according to the warming or cooling effect that is necessary in order to maintain the high temperature superconductor circuit within a predetermined temperature range, where the range of temperature fluctuation is within plus or minus 0.1 K of a predetermined temperature.

Abstract: An electrical interconnect provides a path between cryogenic or cryocooled circuitry and ambient temperatures. As a system, a cryocable 10 is combined with a trough-line contact or transition 20. In the preferred embodiment, the cryocable 10 comprises a conductor 11 disposed adjacent an insulator 12 which is in turn disposed adjacent another conductor 13. The components are sized so as to balance heat load through the cryocable 10 with the insertion loss. In the most preferred embodiment, a coaxial cryocable 10 has a center conductor 11 surrounded by a dielectric 12 (e.g. Teflon.TM.) surrounded by an outer conductor 13 which has a thickness between about 6 and 20 microns. The heat load is preferably less than one Watt, and most preferably less than one tenth of a Watt, with an insertion loss less than one decibel. In another aspect of the invention, a trough-line contact or transition 20 is provided in which the center conductor 11 is partially enveloped by dielectric 12 to form a relatively flat portion 28.

Abstract: A temperature controlled cryogenic package system for efficiently and precisely monitoring and controlling the operating temperature of a high temperature superconductor circuit placed on a substrate. The cryogenic package system comprises a heating element formed on the same substrate as the high temperature superconductor circuit, a control circuit capable of activating and deactivating the heating element, and a temperature sensor placed in thermal proximity to the high temperature superconductor circuit. The temperature sensor monitors the operating temperature of the high temperature superconductor circuit, and conveys temperature information to the control circuit. The control circuit activates or deactivates the heating element according to the warming or cooling effect that is necessary in order to maintain the high temperature superconductor circuit within a predetermined temperature range, where the range of temperature fluctuation is within plus or minus 0.1 K of a predetermined temperature.

Abstract: Lumped element electrical components, such as inductors and capacitors, are formed to include high temperature superconducting materials. In the preferred embodiment, thin film epitaxial high temperature superconductors are patterned to form capacitors and inductors on low loss substrates. Preferably, a ground plane is formed on the back side of the substrate, most preferably being formed of high temperature superconducting material, or other highly conductive materials such as gold or copper. Various advantageous structures include a planar spiral structure, a zig-zag serpentine structure, a single coil structure and a double coil structure. Single layer and multilayer structures are included. Improved narrow bandpass filters, bandreject filters and high Q resonator structures are formed. Chebyshev bandpass filters are formed from multiple series connected zig-zag filter structures.