Not Available

Not Available The design and fabrication of novel power transistors and electrical converters for cryogenic operation is proposed. The gallium arsenide power transistors and electrical subsystems cannot only reduce the circuit heating and radioisotope source requirements aboard satellites, but can also improve by more than a factor of two the electrical power management subsystem efficiency by reducing on-state resistance losses. Also, higher switching speeds can reduce the size and mass of components and power modules. Under Phase I, transistors with isolation voltages of up to 100 V will be tested to manage the 28¿4 V unregulated satellite bus. Phase II effort will concentrate on designing a family of scaleable devices and power management subsystems which are capable of 10¿s of amperes absolute current, 100 to >2000 V breakdown, >1000 A/¿s slew rate, and/or >500 kHz frequency switching.