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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The effects of proton displacement damage on light-emitting diodes and laser diodes are discussed, comparing the radiation sensitivity of current technology devices with older devices for which data exists in the literature.
A novel catastrophic breakdown mode in reversed biased Silicon carbide diodes has been seen for low LET particles. These particles are too low in LET to induce SEB, however SEB was seen from particles of higher LET. The low LET mechanism correlates with second breakdown in diodes due to increase leakage and assisted charge injection from incident particles. Percolation theory was used to predict some basic responses of the devices, but the inherent reliability issue with silicon carbide have proven challenging.
Optical metrology system reliability during a prolonged space mission is often limited by the reliability of pump laser diodes. We developed a metrology laser pump module architecture that meets NASA SIM Lite instrument optical power and reliability requirements by combining the outputs of multiple single-mode pump diodes in a low-loss, high port count fiber coupler. We describe Monte-Carlo simulations used to calculate the reliability of the laser pump module and introduce a combined laser farm aging parameter that serves as a load-sharing optimization metric. Employing these tools, we select pump module architecture, operating conditions, biasing approach and perform parameter sensitivity studies to investigate the robustness of the obtained solution.
This presentation contains test results for destructive failures in DC-DC converters. We have shown that Schottky diodes are susceptible to destructive single-event effects. Future work will be completed to identify parameter that determines diode susceptibility.
In this work, we discuss the observed single-event effects in a variety of types of diodes. In addition, we conduct failure analysis on several Schottky diodes that were heavy-ion irradiated. High- and low-magnitude optical microscope images, infrared camera images, and scanning electron microscope images are used to identify and describe the failure locations.
Efficient heat sink is provided by soldering diodes to metal support bars which are brazed to a ceramic base. Electrical connections between diodes on adjacent bars are made flexible by metal strips which aid in heat dissipation.
Removing a section of the electrode area from the N-face of injection-luminescent diodes for pumping lasers substantially increases light output. Light is emitted from the N-face as wel as from the four edges of the diode.
Grounded-base transistor is placed in a tunnel diode threshold detector circuit, and a bias voltage is applied to the tunnel diode. This provides the threshold detector with maximum voltage output and overload protection.
High-current zener diode is connected in series with the positive input terminal of a dc supply to block the flow of direct current until a high-frequency control signal is applied across the zener diode. This circuit controls the switching of large dc signals.
Unusual transistor connection that substitutes for a silicon diode and allows significantly higher repetition rates without increasing power loss rectifies an alternating current. Operation speed is improved by a factor of 10 or more when a given diode is replaced by this transistor circuit.
Epitaxial gallium arsenide diode junction formed in a crossed waveguide structure operates as a variable reactance harmonic generator. This varactor diode can generate power efficiently in the low-millimeter wavelength.
Fused diode combines a semiconductor diode and a circuit protective fuse within a common transparent cartridge. It provides visual indication of fuse condition which precludes the necessity of making resistance checks with an ohmmeter.
Transistor biased amplifier has a biased diode discriminator driven by a high impedance /several megohms/ current source, rather than a voltage source with several hundred ohms output impedance. This high impedance input arrangement makes the incremental impedance of the threshold diode negligible relative to the input impedance.
SiC/Si diode pair provides automatic range change to extend the operating range of a logarithmic amplifier-conversion circuit and assures stability at or near the range switch-over point. the diode provides hysteresis for a trigger circuit that actuates a relay at the desired range extension point.
Gunn diodes small signal impedance functions variations with length and bias current density and type of diodes
Tunnel diode circuit, capable of timing the zero crossing point of bipolar pulses, provides effective design for a fast crossing detector. It combines a nonlinear load line with the diode to detect the zero crossing of a wide range of input waveshapes.
Small signal characteristics and frequency response of diode-stabilized integrated linear circuits, discussing feedback, impedance, bias- diode, etc
High efficiency oscillator using avalanche square wave diode, considering case of silicon p-i-n diode