Low-Noise Cryogenic Germanium Junction Field-Effect Transistor GPD Optoelectronics Corp. Salem, NH

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Low-Noise Cryogenic Germanium JunctionField-Effec
t TransistorGPD Optoelectronics Corp.Salem, NH
Small Business Innovation Research
INNOVATION Developed Junction Field-Effect
Transistors (JFETs) for deep cryogenic
applications.

• ACCOMPLISHMENTS
• Demonstrated Germanium JFETs that exhibit very
  low noise over the cryogenic range down to 30K
  with stable DC characteristics. Other types of
  available transistors only provide low-noise
  performance down to about 80K.
• Improves scientific return by making optimum use
  of sensor capabilities in space missions.
• These germanium JFETs can operate down to the
  lowest cryogenic temperatures ( 1K), although
  their noise increases.
• GOVERNMENT/SCIENCE APPLICATIONS
• Provides the active element in cryogenic readout
  electronics for NASA infrared sensors, visible
  range photodetectors and x-ray detectors.
• Have applications in materials research,
  astronomy, particle and nuclear physics, and
  solar system exploration.
• Evaluation by NASA for use in cryogenic sensor
  preamplifiers in scientific spacecraft.
• Prototypes have been provided for evaluation to
  interested parties in government organizations
  and universities.

Germanium Junction Field-Effect Transistor
(Insert) and Cryogenic Noise Performance

• COMMERCIAL APPLICATIONS
• Prototypes provided to commercial company for
  evaluation as an instrument preamplifier.
• Possible application in cryogenic end of
  interface circuitry for superconductive
  electronics.
• GDP is continuing development to further improve
  characteristics.

Points of Contact - NASA -Murzy Jhabvala
301.286.5232 - GPD - Rufus Ward 603.894.6865
Goddard Space Flight Center
1996 Phase II, SS5-049, 2/14/01