NASA 1996 SBIR Phase I

PROJECT TITLE : Gallium Arsenide Static Induction Transistors for Power Switching in Cryogenic Power Management and Distribution Modules in Space Probes and Satellites

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

The design and fabrication of novel gallium arsenide (GaAs) static induction transistors (SITs) for cryogenic operation as the power switching transistor in space-based power management and distribution modules (PMADs) is proposed. The shallow donor and acceptor energy levels in GaAs enable transistor operation to temperatures <40 K, which are well below the freeze-out range of Si devices. The GaAs SITs can not only reduce or eliminate the circuit heating requirements aboard satellites and deep space probes, but also can improve by more than a factor of two the PMAD efficiency by reducing on-state resistance losses. Also, higher switching speeds enable the use of smaller capacitors and inductors in frequency or pulse width modulation power converters, thereby easing the fabrication of near lossless superconductive passive components. Under Phase I, GaAs SITs will be tested to manage the 28ñ4 V unregulated satellite bus voltage supply with an isolation voltage of 100 V for safe and reliable operating margin. The Phase I GaAs SITs will be qualified at 0.5-1.0 A current capacity at <40 K; GaAs SIT designs operating at 100 W or more as needed for NASA missions will be produced under Phase II.

Applications with NASA requirements also exist in the low earth orbiting satellite (LEOS) market. The high performance commercial market includes compact and efficient switching mode power supplies, longer running uninterruptable power supplies (UPS), and rapid recovery power factor correction (PFC) equipment. Robert Hickman II, SVT Associates, Inc., 7620 Executive Drive, Eden Prairie, MN 55344

SVT Associates, Inc.,
7620 Executive Drive,
Eden Prairie, MN 55344