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Electronic Components and Circuits Electronic Systems Physical Sciences Materials Mechanics Machinery Fabrication Technology GOGY YO O OR Life Sciences COMPLETED 4% 0490/7794 > 7A a ~1 y~n te myp.e= 2 Xf: dat osC -a *" | - odP ? t=e ~ eDe e3 : *a —e a Tr‘ .S < : ' = 4 F+ ae OS- ae ee 4% te Bi ae er . bs - 4 . — . ~ a ee ae ao PS ate 9 A oe ,- “Se _ DERE Linn DISETBO hoe pt _ — a ‘ - — z . 5 — _ - . =7 i > ae ‘ , = «7 « : ,: 2 Php : % ~ ; : 7% amt mSOR SeLe e , : a . ~ ” Sagan i oe= SS cceae ee - a S-2 « mex i »~ : 9 Fat - : am oaa ~ b:- e aw 4S PS ~ta*e ra 2. = @ E. R“ - SYE'Ps Se “ - <2 =< Availability of NASA Tech Briefs and TSP’s Distribution of NASA Tech Briefs, a monthly periodical publication, is limited to engineers in U.S. industry and to other domestic technology transfer agents. Requests for individual Tech Briefs or for Technical Support Packages (TSP's) announced herein should be addressed to NASA Center for AeroSpace information Technology Transfer Office 800 Elkridge Landing Rd. LinHteighhts,i McD 21u090m-29 34 TeleNop. (h301o) 6n21-e02 45 Please reference the three-letter five-digit contro! number located at the end of each Tech Brief. information on NASA's Technology Utilization Program, its documents, and services is also available at the same facility Technology Utilization Officers and Patent Counsels are located at NASA field installations to provide technology-transfer access io industrial users. Inquiries can be made by writing to NASA field installa- Technology Utilization Officers and Patent Counsels Ames Research Center John F KennSpeaced Cyent er Jet Propuision John C. Stennis Space Center Technology Utilization Officer Utilization Officer Utilization Officer Officer Mail Code 223-3 Mail Stop PT-PMO-A Mail Stop 156-211 Code HA-30 Moffett Field, CA 94035 KenSpance Ceentedr, FyL 32 899 4800 Oak Grove Drive Stennis Space Cente’ MS 39529 PasadeCAn 9a11,0 9 Patent Counse/ Patent Counsel Mail Code 200-11 Mail Code PT-PAT Moffett Field, CA 94035 KenSpance Ceentedr, FyL 32 899 NASA Headquarters Technctogy Officer Utilization Officer Utilization Officer Code CU Mail Cote 702-1 Mail Stop 143 Mail Stop 180-801 WashingtDCo 2n05,4 6 Greenbe't, MD 20771 Hampton, VA 23665 4800 Oak Grove Drive Pasadena, CA 91109 /ssistant General Patent Counsel Patent Counsel Coufonr Psatenet Mlatte rs Mail Code 204 Mail Code 279 Patent Counse/ Code GP Greenbelt, MO 20771 Hampton, VA 23665 Mail Code 180-801 WashingtDCo 2n05,4 6 4800 Oak Grove Drive PasadeCnA 9a11,0 9 Lyndon B. Johnson Space Lewis Research Center George C. Marshall Space DryFlidght eResnear ch Utilization Officer Flight Utilization Officer Mail 3 Utilization Officer Utilization Officer Mail Code IC-4 21000 Road Code A M/S 021-31 Houston, TX 77058 Cleveland, OH 44135 — Bid483g2 W.hse 7 Pe tent Counsel Patent Course! EdwarCdA s93,52 3 Mail Code AL3 Mail Code LE-LAW Patent Counsel! Houston, TX 77958 1000 Brookpark Road Mail Code CCO1 Cleveland, OH 44135 — 1 NASA Tech Briefs, February 1999 1 BLANK PAGE NASA Tech Briefs, February 1999 5 Electronic Components and Circuits 17 Electronic Systems 23 @~Physical Sciences 33 Materials 39 Mechanics 45 Machinery 51 Fabrication Technology 55 Matheand minfaormtatiicn cScisenc es This docurnent was prepared under the sponsorship of the National Aeronautics and Space Administration. Neither the United States Government nov any person acting on behalf of the United States Government assurnes any liability resulting from the use of the information contained in ttds document, or w=-varits that such use wil be free from privately owned rights. NASA Tech Briefs, February 1999 3 BLANK PAGE 12 GaAs-MembrMixaer nfore Op-eraDtioin oatd 2.e5 T Hz 13 Three-Level Buck dc-to-dc Converter for Low Temperature 14 Novel Full-Color Cathode Ray Tube for Miniature-Display Applications Using Surface-Plasmon Filters To Generate Scrolling Colors Efficiencies of liquid-cdirspylasy tdeavilce s NASA's Jet Propulsion Laboratory, Pasadena, Califomia Surfacet-unpablle afitserms (oSPnTFs ) have been proposed for use in generating scrolling colors on the faces of liquid-crys- tal display (LCD) devices. In comparison Unpoianzed WhLiigntt [e7 \ with a conventional color LCD device equipped with primaryf-itceros,l ao LrC D device equipped with SPTFs according to the proposal would utilize a greater pro- portion of the available lurninous flux, generating a display about six times as bright, Cut number of peais to one third. A conveconlotr LiCD odenvicae lope r- ates with linearly polarized ight and is equwiith pprimapry-ceolord fit ers, there being a complete set of such Sters (red, green, and blue) in each pbel. Therefore half the available white Bumination is reject- @0 through rejection of one of the polarization components. if one primacorlory i s selected for display in a given pbel at a Qiven time, then no more than about 1/3 of > s-Polarized Biue LCD Pane! All Three Primary-Color and Both Polarization Components of the incident unpolarized white light would be utilized in this schemo. in contrast a convenctoloir oLCnD adelvi ce wastes about 5/6 of incident unpolarized light because it rejects one polarization compo nt and two of the three color components. ike this : the sich and the thd sections ave SiTilarty to the top assembly, except that it red, the fifth and the second sections ae would be configured to receive the green, and the fourth and the first sections remaining Gownwerd-reflected light, and are blue. Al the next moment, the second its SPTFs would be made perpendiouky 1/3 of the 1/60 second, the colors scrolling to those of the top assembly so as © downward, the imageon the biack-and- expio# the s polarization of this light. Uniike white LCD screen would look fixe this: the i @ Conventiond color LOD, the two sith and the third sections are bie, the assewouldm utilbize lbothe polasrizat ion fifth and the second sections are red, and compaond anl theree ncoltor scomp o- the fourth and the frst sections are geen. nerts of the wie AuminatTihuos,n .th e At the last 1/o3f t he 1/60 second, tte Gispllay would be about 6 times as bright image on the black-and-LwCDh isctreee n as is a conventionLaOlD. would look fike this: the sith and the third During each third ofa frame period, the sections are green, the fifth and the second voltage applied to each SPTF could be Chathrene tigmese fas ter, ie, a 180-Hz sections are blue, and the four) and the Changed so as to change *s pass wave- frame rate is needed. For earnoie, at the frst sections are red. Therefore, one sees a length band to that of a Gfferent primary frst 1/3 of the 1/60 second, the image on Af color image at 60 Hz. color. The temporal sequence of voltages @ black-aLnCDd sc-rewen hwoiultd elo ok The bottom assembly would function applied to the six SPTFs could be chosen NASA Tech Briefs, February 1900 7 to “nake the colors on the corresponding in accorwihd Paubinc cLawe 9 6- Mai Stop 122-116 six gubdivisions of the cisplay area scroll 517, the contractor hes elected to retain 4800 Oak Grove Drive Gownwerd or upward. Mle fo tis invention. inquines concern- PasadeCnA 9a1,10 9 Ths work wes done by W Wew of sng nits for &s commerucsei sahlou l 618) 354-2240 Caltech for NASA's Jet Popuisiolnab 8=— s_sb e. acivessadf o Refer to NPO-20110 , voluanmd neur m- oratory. Furthe miornato ) & cortaned n Technology Raporting Office ber of this NASA Tech Brnets esue, and @ TS? see page |) JPL the page number Magnetic Random-Access Memories Advantages | unlimited cyciability and NASA's Jet Propulsion Laboratory, A Magnetic Randorm-AccMeemsosry . CMOS Active Memory Cirout (MagRAM) is an array of bistable mag- \ netic memory gements with semicon voo Guctor amplifier and addressciircnuigtr y MagRAMs are in the early stagos of Gevelwhoichp hams ebeenn mtoti,vat ed by @ need for nonvolmaemotriia}l ewi th WV vo Y \A— high densities and unimited cyciabAty — @ comboif pnropeartites ithaot hans n ot i been achieved in nonvolaetleictlroeni c RAMs. in principle, the magnetic memo- % ry @ements in MagRAMs can be made free of fatigue and thus capable of uniim- ited cyciabiity. Magnetic memory elements provide signals of reasonamabgrltued e hmacomsams that can be anpliied by semiconductor @ecroric crouits, and offer the additional advaofn raditatiaon ghardeine ss. in a MagRAM, data is stored in the magnetic states of the magnetic memory de- eBaaaen ae ments, which are hysteretic. The data is read fom ese elements by using te magnetoeffrecet tso siensse tthevr ema g- netization states. Figure 1 is a airnpiied schematic dagrarn of a 16-bit MagRAM. A Gesibit gdlemnnent ais taddreessded, for readoir nwilgtin g, by the applicationo f apprcurorentps tro thie waordt-inee fo w) Condand usenscing-tine o(corlumns) c on- Guctors that intersect at that element. The current in the word-ine conductor gener- ates the magnetic field to wite 4 bit int he Gesignated element. A bit (0 or 1) is written in an d@ement by applying a sensing curert l, together with a writing word current +1, for a0 oF +4, for 1. Nondestructreiavdoeu t Oft he bit ise ffected by applying |. with (a)a word current -/,,f ollowed by (b) a word cur- rert +1, (ad, During readout, the analog sensing anole and latch act together to Convert the change in voltage on the sens- ng ine to a bt. The currents |, io, and |, are Chosen according to the hysteretic and maynetoprroeperstieis santd ithve neee d * © prevent spurious wilting in inactive cals - @ssed by active worcine conductors. ee ee eee ee wae ee = | A low-1d6-biet pnrotsotyipe tMaygRA M based on the concept is Bustrated in Figure Figure 2. This Prototype 16-8% MagRAM and Dieniay Unit contains discrete integrated-cir- cult chips that would be combined into a single chip in an advanced production version. 2. This assembly is made fom discrete NASA Tech Brie’s, Februa1r9y9 9 subsystems n the sense tat fe tncton- Ths work wes done by Forney Katt and Technology Reporting Office @ bods micaied hnA gveigemple Gort Gees of Cate & NASA's Jct JPL mented by means of miecomecting Propulsion Laborafory Aste morme- Mail Stop 122-116 Seperate Megaled-croz cups Subse ton is contained na TSP jsee page 1} 4800 Oak Grove Drive Quert development efforts are expected to in accordance with Public Law 96- PasadeCnA a91,10 9 wad to te rmegaioncoiamageicand 517, the contrhesa elcectted oto rreta in (818) 354-2240 @ectoric MagRAM components onto a title to this invention. inquines concem- § Aefer toN PO-2v0olu1me3 an1d ,ru m- sarge Cw tal woud fealre ngh mero- ing nights for its commerucsei saholul d _—— ber of this NASA Tech Briefs ssue, and ry Gansity and low power consumption. be addressed to the page mmmber Digital Approximation Premodulation Filter This filter closely approximates the desired wave Dryden Flight ResearCecnther , shape, regardiess of the bit rate. Edwards, California A digital soifion for the probiern of Mer- ing serial cigts Gata prior to modulation of a telemetry tansmitter has been developed ‘ | by engineers at the Dryden Fight Research j Canter. The solution is described in a patent a i j application entitled “DIGITAL APPROXIMA- Unt rec POM NRZ 4 Senai Data Signa’ TION PREMODULATION FILTER FOR Gata for telemetry is required, care must A, OO {\— Ovtaut of DAP Fitter of 16 Segments per Bt Figure |. The Digital Approximation Waveform is a c"ahtly degraded version of the output of an analog premodulatifoitnte r e analog Mer (see Figure 1), but this degra- $% | dation sh id be tolerated in the interest we. eet ET < Amoithe i : Jb baer System non-retury-to-zeroout4peutv evi e 2 an L-band tranemitter. Normally, 16 seg- Clock —— ments per bit are used, but in this test, the br ewe radiated frequency spectrun obtained when using the DAP fiter with only 8 sag- <a, sata alas natma eir eel merts was essentialy identica wih that put obtained when using an analog Mer The DAP titer Figure 2) comprises tree SUTMIng arnpiifisr to aporoximate the rise This work was done by Harry Chiles main parts: ‘-' a part that divides each bit or tal of a hall cosine weve for each bt = and Alod Bogue of Dryden Flight into a number of segrnents, (2) a part that vansiion. fft he mteger Yequency multiple §=—-—«sR esearch Center. converts each segrrent into a voltage that of the bit-rate Glock signal is not available This invention is owned by NASA and approtheé outmputa oft ane idesa p re- from the signal source, itc an be generat- @ patent application has been fied. moduterl, anad (t© ain ouotputn buf fer @d fom the source bit-rate clock signal by armnplifier. An integer froquency multiple of use of a phase-tolcookp . the bit-rate clock signal is used to sift the Because the DAP fier is syrctrorized serial igital output through a parallel out- with the bit-rate Glock as desrribed above, put shvft register to segrnert each bit. The tta lways produces the proper wave shape, conversion to @ vORage leva can be regardofe tshes b it rate of the uitered accomplished wv @ resishy aiay ad Gata signal. NASA Tech Bnefs, Februar19y0 0