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| BO~$fHs> 0-Ll -r02 echBNiASeI-2t9/s3- 22C|-oS National Aeronautics and Electronic Components and Circuits Electronic Systems Physical Sciences Materials Computer Programs Mechanics Machinery fh LALOCY/7 5s Fabrication Technology Mathematics and Information Sciences TORRODOE@OOOGY Life Sciences ] 01-05 (Y May 2001 INTRODUCTION Tech Briefs are short announcements ofi nnovations originating from research and development activ- ities oft he National Aeronautics and Space Administratun. They emphasize information considered likely tob et ransferable across industiiel, regional, ord isciplinary lines and are issued toe ncourage commercial application. Availability of NASA Tech Briefs and TSPs Requests for individual Tech Briefs or for Technical Support Packages (TSPs) announced herein Shobe uaddlressded to National TechnToranlsfoer gCeynt er Telephone No. (800) 678-6882 or via World Wide Web atw ww2.nttc.edu/leads/ Please reference the control numbers appearing at the end of each Tech Brief Information on NASA's Commercial Technology Team, its documents, and services isa lso available at the same facility oro n the World Wide Web at www.nctn.hq.nasa.gov. Commercial Technology Offices and Patent Counsels are located at NASA field centers to provide techncogy-transfer access to industrial users. inquiries can be rade by contacting NASA field centers and prograin offices listed below. a ee NASA Field Centers and Program Offices Ames Research Center John F.K ennSpeaced Cyent er NASA Program Ofiices (CC6ab5rlo0al)ki en@6am0 a4Bi-ll1a_7ka5er4 c .onras a.gov JJ(i3i2mn1 )AA llii8bb6eer7rt-ti-6 212@4k sorc .nasgao v AGCeatvr eiNl AoRSpaA y a Hneda doqvuearrsteeer st ecthhneorleo agry ep sreovjeecnGt lsme anoj foM rp uoptcrekontgiiroaalwr n i notfefriecset st tohi antd ustry: Dryden Flight Resear::h aanenay Cessaseh Center Small BusiPnreosgs raImnn o(vSaBtIiRo)n & Office oSfM )S pace Sciences j(e6n6n1y). b 2aB7ea6er-r-3-6nR8iee9dd hhoaarrr tt @dtr- nasa.gov S(.725. 7m) or8e6l4l-o6@0l0a5r c.onra sa.gov (T2r0a2n)s fe3r5 8o-46h52 or (STTR) aah at me Glenn Research Center [email protected] las a gov Roger Crouch Goddard Space Flight Center ey Dr. Robert Norwood AOpfpfilciec aotifo Mnis cr(oCgoradvei tUy ) (301) 286-5810N@ So8ra .gov [email protected] Come We aaalibemien, gov (202) 358-2320 or Jet Propulsion Laboratory GFleiogrhgte CeCn.t eM.a rshall Space rnorwood@mail hq.n asa.gov Granville Paules mM(e8e1nr8tl)ee . 3Mc5c4h-Ke2er5n Z7ze7i@ ej poir nasa.gov S(a2l5l6y) i Lti5tt4it4ie-e@ 4m2s6f6c .noars a.gov JO(f2of0hi2)cr e 3oM5fa8 n-Sk4pi6a5nce9s Flight (Code MP) — (g((2C.p04o2aid)ceu e l3Yoe5)fs8 M@-ims0st7ipo0nhe6o q tr.o na Pslaa.ngeotv Earth Johnson Space Center John C. Stennis Space Center mpaangy 2811)) 489-483-0474 047 or (228)6 88:. 1929 or CaoofsAs v o-Space Techneiney henry.|.davis [email protected] technology@ssc. nasa.gov Cone A (202) 358-4636 or thertz@mail hq.nasa.gov NASA Tech Briefs, May 2001 NASA Tech BrieMfays 2,00 1 @ TechBriefs “" National Aeronautics and Space Administration 5 Electronic Components and Circuits 11 Electronic Systems 17 ~=Physical Sciences 27 Materials 35 Computer Programs 39 Mechanics 43 Machinery 47 Fabrication Technology >|H0O0#Mt\ 0| /9'8 51 Life Sciences This docurnent was prepared under the sponsorship of the National Aeronautics and Space Administration. Neithet Unhiteed rSta tes Government nor any person acting on behalf of the United States Government assurnes any lability resulting from the use of the information contained in trys document, or warrants that suct: use will be free from privately owned nghts NASA Tech Bnets, May 2001 —_ Electronic Components and Circuits Hardware, Techniques, and Processes 7 Simplified Construction of Conica! Log-Spiral Antenna 7 High-Performance Micromachined Linear Arrays of Thermopiles 8 Oscillator-Stability Analyzer Based on a Time-Tag Counter NASA Tech Bnets, May 2001 o}f] i, nin yi SD ILA EAN i Ty PAE Simplified Construction of Conical Log-Spiral Anten eee Mating parts align themselves Lyndon 8. Johnson Space Center, Guring assembly. Houston, Texas An improved design for a conical loo- spral antenna (see Figure 1) simplifies con- Two Feed Porus Struction and improves alignment. The radiating-diement substructure of such an amtenna must be properly aligned with the signa@-iesd substructure to obtain the cor- rect impematcdh faor efniciacnt ceoupl ing of the signal into or out of the antenna. This Gesign provides for matting parts, the faying surfaces of which enforce alignment ivtialy Gurng constanrd muanctant aolignnme nt subsequeGunnitngl uyse . Heretofore, the tabricalion of a concal (1) etching a sheet of metal to form te aroua nmoidd or (2) manually aigning 2 On @ Single-piece polytetrafuoroethyiene Figure 2 A Machined Polytetrafiuorcethy!- body (see Figure 2). The use of a machined ene Body defines the spatal reladonstups sokd piece Quarantees consistency of the among the spral armns and feed wires. thereby cone angie. The inside of the body ss enforcing alignment. machined to provide space for a board that hokis the feed crouil, plus key sts that This work was Gone by Roland W. Shaw accept opposite edges of the board, thus of Shason Microwave Corp. for Johneon agg the feed wres with the loo-spral Space Center further information is patie. instead of wrappain entcghe d containeidn a TSP jsee page 1) metal spral onto the cone, the loo-spral MSC-22334 High-Performance Micromachined Linear Arrays of Thermopiles These uncooled infrared detectors can be useful in dispersive NASA's Jet Propulsion Laboratory, specttherrmaol immageers, tande horrizosn se,nso rs. Pasadena, California ’ broad ternpraengre awitthouut trempeer a- Gert infrared power ture stabilTheiy zarea ptassiivoe ndev.ice s, Prior to the developofm thee pnretsen t genea vorltagae ptropoirtionnal gto the hugh)-perGefvicoesr, marraayns ocf tehe r. incident infrared power without electrical mopies had been fabricbya mtcreodme - bias. They require no chopper. Thus, for Chining of silicon, but those arrays some applications, thermopiciaen sb e contained metal or silicon-btahseremndo - Supported by simpler, lower-powmeorre - @lectric matenais, whwch are Characterized relable ancillary Components than are by low thermoelfiegucrets rofi mcer it. [A needed for the operatian of such infrwed matenal’s thermoelfiegurce tofr mierict is Gevioes as bolometers, pyroelectric or fer. definbey d7 = a*/pA. whear ise t he rogiectric Getectors. Another advantage is Seebeck coefficient, p is the electrical that ift heramre oreadp oiut ewiths hi gh resistivity, and A is the thermal conductiv- input-impedance amplifiers, they exhibit ty] The signal-tratoio- onf oani insfreare d naghgible excess low-frequ(1e//n cnoyw e Getector can be Gescribed by the speciiic Therrespmonseo isp typiicallly hieghly iin- Getectty(,0 ). The D' of a thermopilies 6a Over Many orders of magr¥tude in inc- approximately proportional to Z'/ memovebr a rhole am Ten soeon s.b- State to m@enve te hema isoiaion of the Termoencctonos ufomp thee s ub- State (see figure) The thermocoupfliem s See a ae Ee Cde eanie tes be te of compounds has te nected to each other and gold interconnect wring with contact pads made of gokd fim depoosveir tttaneum dfi n. When exposed to radiation forn a 1,000 K blacsoukrce,- thbe deotectdors yext wb- fed 2er0 fequency responsivavliuets yo f 1,100 V/W and speciiic detectiites of D’ « 14 10° onewh" a ?respo nse time of 99 ms. The orfy measurabnloese at frequencies above 20 mHz was Jonson nose tom te detector ress- tance. These perforfimguaresn acree t he best reported to date for an array of ther- mopile Getectors. This work wes done by Marc Foote, Enc Jones, and Thierry Cailiat of Caltech for NASA's Jet Propulsion Laboratory This invention is owned by NASA anda Nowe AlTOugh some denenaons ae show Ormeng sok ae patent application has been fled. inquines concerning nonexclusive or exclusive Bi, oy g/Bly ggS d, agT @, . Thin-Film Thermocouples electrically connected in senes were license for its commercial development tabncatet on a sicon nitride film over a hole in a silicon substrate by standard depositon and should be addressed to the Patent micromachining techniques. Counsel, NASA Management Office-JPL The present Gevices are 63-elernenitn - 11 B-Te/tBhin--tiSn tdher-mocToupeies , [see page 1) Reter toN PO-20402. ea arrays, wih each genet containing which are supported on a gloon nitrides Oscillator-Stability Analyzer Based on a Time-Tag Counter This system would combine the best characteristicosf NASA's Jet Propulsion Laboratory, prior single- and dual-misyxsteemrs . Pasadena, California A proposed system for amuitaneous moe analyzers exhibit low measurement minated by uncannooisee frlon ethde o f. Charactofe thne iznstaabiltity iofo senver al noise, but an Offset-requency reference set-rrefeereqnce uosceillantor.c Thye p ro- precise, low-noise oscillators of norninaly oscillator is needed for each par of nonref- posed systern would take advantage of a equa frequency would be bull around a modern hgh-rate time iag counter to col- commercially available time-tag counter lect ZerO-ctimres oofs besat inotnesg, t he One of the oscillators would be Geerned to nominal frequency of which must be much be a reference oscillator, and each of the exhitts noise greater than that ofa single- Greater than the Gesrdaeta dra te. Then Oher oscillators would be compared with mixer analyzer The proposed system the systern would effect a combinationo f i, by Operation of @ combinatofi ohanrd - would offer both the convenieanndc leo w interanpd aoverlaginag tto piroocesns t he ware and software. in addition, without fur- cost of a Gual-nber anelyzer and meea- time tags into low-rate phase residuals at wer modifofi thce haardtwarie, oanyn t wo surement noise about as iow as that of the the desigrride tidme s. The advantagovee r norveterence oscillators could be corm- best single-moer analyzer prior art would be greater cancellationo f pared with each other vie software. A typical prior Gual-sntabbiliety ran e- the reference nose The design of the proposed stability lyzer utlizes interpoorl eaxttraipoloatnio n analyzer is of a type called “dual mower” in to Convert several mooherent channels of tern. The oscillators to be compared would beat-note Zero crossings into phase resid- be of nominal frequency v.. The frequency uals at a predetegridm oif tnimees,d s o of the reference os. lator would be offset that the residuals of ary two Charnes | by an ammount v,. The offset referencsieg - the ¢ Aputs of two mixers. There are aiso and | can be subtracted to give an /-vs. + na would be maxed wih the sonal fon singie-mocer stability analyzers Single cornparison. This measuremise onctta - eacofh t he norveterence oscillators, and NASA Tech Brefs, May 2001 i ; i — The Duai-Mixer Stability Analyzer would perform some of its functions in hardware and some in software The back end of the hardware por- bon of the system would be a hugh-rate tne-tag Counter hat would measure the tres of zero crossings of beal notes. the moe outputs would be low-pass #- tor at Charmeis. The averages tus com two par channels coud be differenced to tered, thereby generating beat notes of puted would constitute one of the sets of give a synthesized dual-moxer j-vs.-/ nominal fequency v,. By use of ze output data of the system. An essential fea- Channel. The ability of tis system to sup- Crossing Getectors, the best notes would ture of the design is that r, must be much press the noise of the reference oscillator be converted to square-swgnaaisv. eTh e Greater than the beat period tr, = 1/v,, would Gapend on the relation 1, >> 4, tne-tag Counie would Captive the 2er0- Each beat note would yield phase resid- Ths work was done by Charies Greenhal crossing time tags of al the beat notes on uals for one parched leg. te th of Caltech for NASA's Jet Propulsion @ Commtoimen a ds Channa, defined wih respect to the fh Laboratory futhe niomnaton «6 con in software, the te tags would be con- oscillator (a nonrefeoscrilleatonr) cvse. t he tained na TSP jsee page 1) verted to phase resduals Tel would be zeroth oscillator fhe reference oscillator) NPO-20749 averaged Over sequential tervals of dura- Because the averaging intervals would be tion7 . These imerva's woud be the same the sarne for af par-chantnhee Giasta, t or NASA Tech Bnets, May 2001