1-Time Variable Gain Circuit

8/6/2019 1-Time Variable Gain Circuit

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a aigy ol 36 No

INRU D METHODS

A GAL LW-FQCY, FACPFCAA Y

B AVID WRGT

US Gologal Svy MS 64 Bo 546 Fdal C Dv Coloado 85 USA

TEVEN M. ODGE

U.S Gologal Svy Uvsiy o Pg Sod Taoma Washgo 8416 USA.

JERRY A DLEY HOMAS P ROER,

U.S Gologal Svy MS 64 Bo 546 Fdal C Dv Coloado 85 USA

and OBER W JACBEL

Dam o Physs S Ola Collg Nohid Msoa 5557 U.S.A

BSTRAC. A w sho-ls dgial olig adasysm ha oas a ow qis ha mos iadas sd ola gos o da has b dsigd adbil by h US Gologia Svy Th asm s a

avalah asiso ls whh divs a sisvy oadddo asmiig aa. A simila b saa aas od o h iv Th iv has adsablssiivy m oo STC o as mh as 6 dB oomsa o aao ad gomi sadig aosA bo abl is sd o asmi boh oo sgalsad daa Th daaaqisio ad dislay sysm ooas vy hghsd dgzg ad siga avaggal-m ol dislay ad daa soag o sadadom -a mag a

Th sysm was ssslly sd o I Sam B Ws Aaia a qis o 4 8 ad15 MH Boom sigaoois aios o mo ha4 dB w obad a MHz hogh 8 m o iCovold ial sas o lad o s boomoogahy w sovd wih h sams adaomalos sog los o "bigh sos" w dida h bas o h A s h is o saisaoyglaiologial laaio o h o hs obsvaios

INTRODUCON

Sa ad aibo ada sysms o sds o olaad ma hav b sd o som im A mbo ada sysms ad h gal sb o lomagisdis o i a wll dsibd Bogoodsky ad ohs(85) O o h mos sssl sysms o aibosodg o d oa i was bil by h ThalUivsiy o Dmak ad ovids a bhma agaiswhh oh sysms may b omad o mod

asms a slabl lgh ls oaiig a mb oyls o a 6 MHz a qy So adSodgaad 176) Aaivly his ada a moyls asio ad omssio by qy swighiig

Aoh y o ada sysm alld a shos oimls ada has b dvlod ha idally adas olya sigl y a a qy dmid by hgh o ssvy loadd do aas By qy w ma h qy o h a o h owsm o h adiad ls Commia sysms o hs

y yally oa a qis bw 8 MHzad GH ad a wll kow i shaowgod sdsUls 83 A vaiaio o hs y o ada Wasad Wigh 81) sig mh og aas ad

ho low qis was dvod o aibooig o ma i wh iqid wa is sb has aaios o ola as wl aialy wh s moa o sv has iomaio i hodd wav om o wh lomag losss h ias sbsaialy wih qy Th ada sysmdsbd i hs a is o h lowqy sho-lsy b ss a mb o hams mad ossbl by advas aalog ad digia los adlo-os Wigh ad ohs 8)

Th sysm was sd o I Sam B WsAaia dg ovmb ad Dmb 87 Thobiv was o s ada o h sam o la abos as ad s bhavio is ia s ad basalodos ad is ossib sos o limai wamigTh ada sysm was oad a 8 ad 5 MHzad som lis w oild a sva qis omi qaav amaio o ad-os bwaams sh as sigal-o-ois SN aio ad solio addio i s d ha a syhsis o h daaodd a d qis wil yld moomaio abo hysial homa wh h i ad ah bd

SSTEM DESCRIPTIO

ecrcA blo dagam o h sysm is show i Fg I

Th asmi ad iv show wihi h dashdois a boh owd bhd h ismaio h

Th digia daaaqisiio sysm DAS om adiv ad gai-oo i a sid h h ad aowd by a 4 kW gasoli-owd gao This sysmwas dsgd siialy o aqisiio avaggodig ad dsay o daa digia om whiog h h DAS is al o h oao o hsysm A digial osiloso od b sbsid o hDAS b wih sigia dios i avagig ad daaas as A ll dsio o h AS is giv iWigh ad ohs 8)

Th bay as o h asmi ad iv


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right and othrs Instrmnts and mthods

TRANSMITTER

WR "WAK-UPIRCUIT

JHIG VLTAE

POWR SUPPY

JPLSRTRASMITT I G

ANTA

FIBR OPTI

RCIVER'T--rl GNRATOR: ODOMTR

FIBR OPTI ,TRIER #RCIVER : t

l

AIN RAMP

NRATOR!ST

RCIVER

RIVING

ATNNA

AIN

OTRL

OPUTRt

RT IRF DATAI FIBR PTI I4 TRANSMITTER

L RIER #

DA S

I RC IV R t---------------- L

ig Blck diagra of th ctronics of th ic-radar sstm riggr #1 fit tu the latching"wakeup ii to app y high votag to th pus; sb squnt triggr signas fi th puigg #2 iitiates th gain ramp in th rcivr S ns itiity tim contro C) gain tupommands ae also tansfrrd on this chann triggr signas and th adiofrqucy angdata a tasmied or a mutifibroptica F) cab

conss o sx seae eacd V aeres raed a Ahcapacy The curren reuremens or he ransmerepen on he ranssor ype used, snce deren ypeshave deren rea-own voage rangs and on herepeon rae o he puser As operae n Anarcca, heransmer reured approxmaey 50 mA a 30 V a arepeon rae o 5 Hz The aery capacy s su cenor h o non-sop operaon uner hese condons, evenaowng or some erang o he aeres

over a range o npu voIages rom 431 V. The rseaure aows deren ranssor ypes o e use n hepuser, an he secon provdes a consan ransme sgnaeve even hough aery voage ecreases urngoperaon

Because he hghvoage ransmer power suppyconsumes he mos power, even when he puser s norng, a "wake-up" crcu s empoyed ha appes voageo he npu ermnas o he power suppy ony whenrgger puses are sense The rgger puses are generaedy he DAS he sysem s n san-y mode (no puses,

he aery packs w as or more han 4 h.The hghvoage power suppy a Venus Scencode F, has an oupu voage adusae over a rangeo 30000 V an w manan a co nsan oupu voage

Eecromagnec coupng eween he ransmer,recever, an vehces was mnmzed y usng a Secoraeecrc consrucon muer opca cae hacarres rgger sgnas, conro commands, and he raoreuency receve sgna Each o he nes passng hroughhe dashed oxes n gure represens one er n hemuer cae The opca cae was aso used as heow cae or he ransmer and recever

The ransmer, shown n Fgure , s a hree-sageavaanche ranssor arx-ank puser A arxank s a

an o capacors charged n parae, u dscharge nseres o gan a voage mupcaon The ransmer ssmar n many respecs o he oder moe used or hearorne soundng o ouma Gacer, Aaska (Was an

Vcc

VouY

ig 2 h thee-stage aaan chtransistor ps his pus can b buit in a bo of about 200 m3

ad ighs oly about 200 g yt dirs pa k output pow r i n xcss of 10 k a t a rptitio ate fup to 10 kHz. V angs from 3 to 6 dpnding th transisto pe ued A ogicleve is fte adequae as a triggr Frt hr discusion ad a parts i st ab ) ar in thAppndi.


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Jl lcily

Wgh 11). Deendng on he nssor ye used n henew moel, he ek ower ouu my be sghy geeo less hn h o he oer ulse Unle he eleveson, he esen one s rggere rher hnee-runnng so h he rnsed ulses nn hsecoherence wh he 100 Hz coc h conros DAS mng.The by o rgge he nsme synchronousy whsubnnosecon shoosho er mxmzes he benes odgl wve-om don, scussed er, n mkes

ossble o obn unom s d ensy n se ovehce see vons The user s comc, gh, esyo bul, n revely elbe cen consrucon ndoeron ecuons re obseve (see Aenx). Furherdscusson o vlnche nssor ccus s vlble neden (6) eneby (16) nd Nchoson nd ohes96).

The recever desgn resened some chenges becuseo lme ynmc nge n he nlogue oc lnk ndhe dgze Dynmc nge o lne nog sysem she o o he mxmum nu sgnl o lner oeono he mnmu deecble nu sgnl. The ynmc ngeo dgze s oxey 6 x dB where s henumbe o bs. A desgn creron o he r sysem wso use vey hghsee DA S wh 100 egsmlejs

gze n hghseed wve-om on o SjNenhncemen (Wrgh n ohers, 99). he gzer eCoy TR1A s n egh-b devce n hus rovdesonly 4 B o ynmc nge n ddon he beoclnk use o rnsm he o-equency receve sgnl ohe dgzer hs dynmc rnge o ony bo u 50 dB he requences we e usng. uch greer ync rnges equre o esolve morn eues resen n he wveo bu whose eun ues e sm cored ohe suce n boom euns, nd o coense osgnl enuon n he ce Fo hs reson, sensvye cono (STC) ws bul no he recever (g. 3).

STC lso known s e-vyng gn, ncreses hesensvy gn) o he receve s uncon o meooon o dsnce) o comense o he smllemlue o eun sgns rom more dsn obecs. In

eo s sho s /S he gn cn be smoohy ved bys much s 60 dB. The by o he mer o esenreceve sgns seed n me by s e s nddeng n mlude by s uch s 60 dB, o he dgze he se mlude (hough no wh he se SjN o)comenses or he me ynmc nge o he gzend be-oc lnk An elecromechnc rogrmmbeenuor ecedes he ecever, bu s use ony when veyge sgnls would sure he mlers n Anrccexce or he lowes equences no such enuon wsused so h he sysem coul cheve he bes SjN o. nhs cse he emler rescs he eecronc lnedynmc rnge o bou 60 B hough e momenyovelods cn be olee.

The wve-om vergng eome n he DAS

moves he SjN o n eecvely roves ddonldynmc rnge subec o he escons scusse beow. nAnrcc, we genelly cohereny dde 06 wve omsor heoecl SjN ovemen o 36 B he culmovemen ws essenly equ o he heoeclmovemen exce o soe slgh sysem-geneedcoheen nose scussed beow. When de o he 60 dB

eeconc ync nge, he sysem hus roved heequvlen o 6 B, o 16 bs, o lne dync rngewhou usng he rogmmbe enuo.

The mxu numbe o wve oms h he DAScn dd whou overlow s 65 536 6 Nozon sno used n orer o eseve he ul dynmc rnge Founcoeled ussn nose n coheen (hseesevng) eceve he heoec SjN (ower) enhncemenerved om sgnl ddon s 10 x g () whee n s he

numbe o wve oms e, hus he xmumenhncemen by he DAS, r ro ny see comuedon whch ws no done n he el, bu cou beeome on he recode d, s dB. Coheren dono wve ors, howeve, ssues h l sgns dd nhse; heeore, lm s se on he hyscl snce hy be vee whle ddng The dsnce s uncon o () he geomec she nd roughness o"ges o neres, such s boom ooghy, crevsses,or nen yers, (b) ossble vercl nenn oon dueo suce ro ughness or cr moon n rbonelcons) n (c) he wveengh o he e sgnl.The m s oe sevee o hgher equences (shoewvelenghs) A se rcce olowed n bore-hole dlcons (gh nd ohers, 16) s o resrc he

moon o he nsmer n receve o no ore hnoneenh o wvelengh durng on. Such sngenlm s no wys necessy n ce, bu n our Anccong he hoonl dsnce rvese urng donws generly bou m, hus hs severe conon wsssed even he hghes reuency use. hereore, llreun sgns, ncung hose ro he sles euesdeecble by he sysem wee e n hse ung heene ddon ocess.

Anohe eomnce gue, somemes conused wheceve ync rnge, s sysem sensvy whch ssomemes gven s he ro o he nsmer xmumouu ower o he eceve num deecbe sgnl. Weee o hs o he eecronc sysem sensvy.Addonl cors, ncludng nenn gn syse lossessuch s hose ue o nenn n cbe ressvy, ulse

exnson n comesson ny, n sgn ecordngenhncemens nee o be nclue when mkng sysemsensvy corsons. For he sysem descrbe here henmum deecble sgnl ower, wh no don sgnlocessng, s heorecly 0 B m 10

W). he eouu ower ro m he ulser s +70 dB m I0 ), so heheoec eleconc sysem sensvy s 160 B. boroyesuemens show n eleconc sysem sensvy o bou45 B The B reucon s ue o elevson nd ronsmssons n he ss bnd o he receve, n o somesysemgenee gl nose rom he gn-conolccuy Snce hee s very e eevson n rdoneeence n Ancc he sysem sensvy should besomewhee beween hese wo vlues Creu nosemesuemens wee no me n he e becuse he

clbe oscor used o sgn leve esureens wsno vlbeFo our sysem, he nenns e ressvely oed o

she he e ulse n re ess econ hn hoseo hghe-requency mu-eeen nenn Ahoughmesuemens on ou nenns re no vlbe, heoeclclculons lce he (wo-wy) ne nenn reconl gn

3 e ecemplie ii dim ensiiviy me n s cclishd si eese cs ce de b ndidh pen mples ih he i se b l -pie eldee siss (ETs sed s lenled esss s ls s in Tble II i eppd

4


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pls esstve osses n te ane of 2 to 6 epennon antenna oan n te antenna oss a te 36 an fo ave-fo ato to te eeto systesenstvty v es a tota syste senstvty of 6579 Bsn te aoatoy ease eeve-nose fe o94 f te eeve eae ts teoeta noselt. f te S wee aoe to a to ts fl apatya tota syste senstvty of 9226 s teoetaypossle t ts ay e pata exept fo vey loal

stes ease of te pase oeene eeetFo opason te 6 H te aa systeevelope y te enal vesty of ea (U)as a ax tanstte poe of te sae aso aa syste t as an eeton syste senstvtyepenn o selete an t of 72 So anSoneaa 976) ntenna a syste osses aeon a st e ae to ave at te total systesenstvty So an Soeaa aate a 22 Btwo-way atena an n a sal atenna feesyste oss an estate a potoap eo an of5 B at typal aone eon spees es e atonsess a sa oss n te tast/eeve st ve a totasyste sest vty fo te syste of 272 B. fse on te e sfae t fast ta sna atons as tat pove y o S even e tota systesenstvtes t e posse O S as aleay eensessfly se wt te aa syste aonepofln of te Geenlan e seet (t a otes99).

Estates of ane vess syste senstvty an eeve fo te aa eaton w s ssse nany aa texts s as te one y Soln (962). seaton speaze to te ase of efeton fo a panatefae ay e wtten te fo

Gn.p et 4(4) R

wee s te eeve poe t s te tanstte

powe G s te atenna an ee we asse tat tetansttn a eevn atennas ae enta n s teantenna a fee-syste effeny . s te avelent netes p s te elet fe efeton oeffent at teeo tefae ven y

p(Er)t ( )t()

! + ( )

fo noa ene wee an ae te eatveelet pettvtes of o an e espetvey. R ste stane etes ease fo te tansttnantenna to te otto. e noe te fat tat teeev atena s not at te sae oaton as te

tansttn atena ease fo sepaaton staes sallopae to te e tness te oeto oes notsstantaly ate te eslts as te nts of an selate to te effetve attenato n B/ y te elato

(B/) = 66.

e effetve attenaton exes te eoet speanfato R, t nles al ote eans y poweesty s ee n te popaatn ave nlnontve osses n te e onvet eetoaeteey to eat satten a ffaton fo nooeneos nsons an evasses n te e a speaefeton fo nteo e sfaes. n exape s potten Fe 4 t effetve attenaton n / as apaaete o eneate tese ves we asse tat G s.6 w s appopate fo a alf-ave pole nfee-spae a s an neestate wen te antea es onte ae tefae e antena effeny s tae to e% te ave et s taen to e 4 w oesponsto a feey of 2 Hz e f te e as a elatvepettvty of 3.2 a te eatve pettvty of te oneyn te e s taen to e , vn a efletonoeffent of .277. e 5 B level e 4epesents te estate eteto t set y te eletonsenstvty of o syste t o wave-fo aton

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1-Time Variable Gain Circuit