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Full text of "NASA Technical Reports Server (NTRS) 20120006514: Rad-Hard, Miniaturized, Scalable, High-Voltage Switching Module for Power Applications Rad-Hard, Miniaturized"

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Rad-Hard, Miniaturized, 
Scalable, High-Voltage 
Switching Module for Power 
Applications 

A paper discusses the successful de- 
velopment of a miniaturized radiation 
hardened high-voltage switching mod- 
ule operating at 2.5 kV suitable for 
space application. The high-voltage ar- 
chitecture was designed, fabricated, and 
tested using a commercial process that 
uses a unique combination of 0.25 pm 
CMOS (complementary metal oxide 
semiconductor) transistors and high- 
voltage lateral DMOS (diffusion metal 
oxide semiconductor) device with high 
breakdown voltage (>650 V) . The high- 
voltage requirements are achieved by 
stacking a number of DMOS devices 
within one module, while two modules 
can be placed in series to achieve 
higher voltages. 

Besides the high-voltage requirements, 
a second generation prototype is cur- 
rently being developed to provide im- 
proved switching capabilities (rise time 
and fall time for full range of target volt- 
ages and currents) , the ability to scale the 
output voltage to a desired value with 
good accuracy (few percent) up to 10 kV, 
to cover a wide range of high-voltage ap- 
plications. In addition, to ensure minia- 
turization, long life, and high reliability, 
the assemblies will require intensive high- 
voltage electrostatic modeling (opti- 


mized E-field distribution throughout the 
module) to complete the proposed pack- 
aging approach and test the applicability 
of using advanced materials in a space- 
like environment (temperature and pres- 
sure) to help prevent potential arcing 
and corona due to high field regions. 

Finally, a single-event effect evaluation 
would have to be performed and single- 
event mitigation methods implemented 
at the design and system level or devel- 
oped to ensure complete radiation hard- 
ness of the module. 

This work was done by Philippe C. Adell, 
Mohammad Mojarradi, Linda Y. Del Castillo, 
and Tuan A. Vo of Caltech far NASA’s Jet 
Propulsion Laboratory. Further information is 
contained in a TSP ( seepage 1 ). NPO-47784 


Architecture for a 1-GHz 
Digital RADAR 

An architecture for a Direct RF-digiti- 
zation Type Digital Mode RADAR was 
developed at GSFC in 2008. Two varia- 
tions of a basic architecture were devel- 
oped for use on RADAR imaging mis- 
sions using aircraft and spacecraft. Both 
systems can operate with a pulse repeti- 
tion rate up to 10 MHz with 8 received 
RF samples per pulse repetition interval, 
or at up to 19 kHz with 4K received RF 
samples per pulse repetition interval. 

The first design describes a computer 
architecture for a Continuous Mode 
RADAR transceiver with a real-time sig- 


nal processing and display architecture. 
The architecture can operate at a high 
pulse repetition rate without interrup- 
tion for an infinite amount of time. The 
second design describes a smaller and 
less costly burst mode RADAR that can 
transceive high pulse repetition rate RF 
signals without interruption for up to 37 
seconds. The burst-mode RADAR was 
designed to operate on an off-line sig- 
nal processing paradigm. 

The temporal distribution of RF sam- 
ples acquired and reported to the 
RADAR processor remains uniform and 
free of distortion in both proposed ar- 
chitectures. The majority of the 
RADAR’s electronics is implemented in 
digital CMOS (complementary metal 
oxide semiconductor), and analog cir- 
cuits are restricted to signal amplifica- 
tion operations and analog to digital 
conversion. 

An implementation of the proposed 
systems will create a 1-GHz, Direct RF- 
digitization Type, L-Band Digital 
RADAR — the highest band achievable 
for Nyquist Rate, Direct RF-digitization 
Systems that do not implement an elec- 
tronic IF downsample stage (after the re- 
ceiver signal amplification stage), using 
commercially available off-the-shelf inte- 
grated circuits. 

This work was done by Udayan Mallik at 
Goddard Space Flight Center. Further infor- 
mation is contained in a TSP ( see page 1 ). 
GSC-157 16-1 


NASA Tech Briefs, October 2011 


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