12,403 research outputs found
Orbiter global positioning system design and Ku-band problem investigations, exhibit B, revision 1
The shuttle Ku-band Costas loop lock detector output signal appears to vary about the lock detection threshold (the lock detect flag is on and off) shortly after the carrier acquisition starts. Real time computer simulation was performed to obtain the signal output from the low pass filter of the lock detector. Based on this simulation, it appears that the oscillation of in-lock and out-lock is related to tracking process and is not caused by the sweep acquisition algorithm
Device modeling of long-channel nanotube electro-optical emitter
We present a simple analytic model of nanotube electro-optical emitters,
along with improved experimental measurements using PMMA-passivated devices
with reduced hysteresis. Both the ambipolar electrical characteristics and the
motion of the infrared-emission spot are well described. The model indicates
that the electric field is strongly enhanced at the emission spot, and that
device performance can be greatly improved by the use of thinner gate oxides
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