BSTJ 50: 9. November 1971: A Microwave Feed-Forward Experiment. (Seidel, H.)

15.8 MB·English

A Microwave Foed-Forward Experiment.
by H. SEIDEL

Cs si Agi 1,02)

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fro Hh 9 sige ots, oud sieaustieg 22
anion, ii nin ne 08 ees
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Mur auotenment, Thee ret

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swith evermoly ln ralulnie.peoduets ever 30-MF wie tis

‘oor sharv, Tha sepetimen eis noid wir cence
Fe exdilty of mash amplisere for Hol savy wk x maepoet of
Theirs imoasing the obeanel eapoety 0” mioweeave radio
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since sim He peso gabon fa U8 Patent 2502-718
sauce in 1352 to WD Tonks wine estecet Mobil’ Hots to
smiemiraves ming trv sie thes nd echer micron ve hw
fo pill rsuncn ws. AP siugosed, there ne furdarerkal Witenes
RO ule os nen eRRENORAG FM, ERE TT

lu the wee pasonted her, peimasiy wich veepect unequal emp
Ulssioe, wel tie explct-equalvation of sgaal path taming: Newer
Shoes the Tare his hae be ntaince yor eatmeucy, eae
“itinntelyto developments parael to tases pesextad bere, probabl
Telfrota ons ta tee aifsrenee af sressres tpunning ‘vont yours.

‘Tbe eeentl tetas of teedtored i staal freon fro eet
ine imitations waich rious Lit the apoliaton of megatv
Teoahceke ct high sroqurstice. IL Seidl, TL I Resricr, ad A. ¥.
Frist,” ia 1057, demousteated the eopabiliton of deedcoreard
velow apglied to VIE ampiters Tmo separatahigherowsr amine,

fe perfing ete 25d 6 MAY rd The ati tens 2 nl
DATs, wee re te sone dymaania mangos of weil vse 100 AB,
tdi einai aires sina ine cree al fede

Th 1960, tae antioe canzonetated the eamabilites of teedtornesd
conte is ipuowing an sxatng Lt coesal cable deteibutios amp cx
"Thin sven, the “oattont af GH traeteon and fredbars a,
feldse a ANA impervemens af tanduletion produete eros th entice
ange of 02 to 0 Rlllge 7 Dol bendvidth. 2 tae funeturs. the
finilutive svidenen made elear thn waith aid eagsabuity of tod
forwasd congo, cad iatarest ore in fe applesility to mennea

1: parfiecarinterem in microwaves fe sho distarion of he pow
butput stego ofa uo sig openers Tes wel non thee ara
fumpression toreer w oqusney swaluiion, or PCM, we fill ator
freeones redusict medion seinen sa eerie eine medal
tion that weuld be otborsse produced. eluate fre uonoy patios
toa, Hewsreny wot alate slllstoting, Shien seh 8 ee
handy neues in Crag of este nnadeningcomvenmfeation
na,

Trader shoar cinta, sin sided mcculetion i an a
Iosctive peepee: senimieg Thay ladon, ci eal te power state
ligitstioa tka wecudas it, Har sample, che affe, of aUreqh
Anctuetine on wiceban szgle sideband trenemion fs, ue vel, ute
fralnsted, hota with eeepe! fa facing and seein, Neverthe,
|¥ one ssaniee the cotinan: linieaie. te be ower sige eompivssion
and, assuming genoallysoneptale sige love, tale seatste. cath
Inerta, ete, fgrtees wish a seeunsphon of HIM) ezine witiin x
vo-stlle cheno, inowrty sequyemenes for the power slego mny be
educed. Tor the Westere Kletrir 401A taveliaeceve tut, the
ever sueurstisn powcr stage urce in the TD syem, caleulotin
shows x rayuined inpawarnent ia mecustioa product uo bebwon
ann feawan coNeRe gst

Awl 37 Tse divengsnoe theca murs eee wn ieee
of phase decoreltion introduced auto chinerder Satenndoatin
sveumoation by transposing Crngding? masierganape at vacons sites
Moxy the Pansnision rate. ‘Ta ahaw the azsapney 9 fecorvanl
freed independent of aulary tevaniqnee, it se the puspese of thia
fener: to akow that diserion redustion omid be armnmplied
Injord he higher, 47 4B, ge

‘Tn make the Hnerity weniersents rarie'y questiteize, let a
imusuatarily view tye Hetnitin 1 the istrnnsluetion means
MGS, Ms dened Hh ser of doses relative t9 one mwa
Bewhich one wll Fad n Punter wot of the form A= TE =
Tile se gnlifer sing Fee ses, 8, Beal Cont a
Flite HLA sratngese abe bas ay MIR ing — 78
ochst 947-18 impenvemect ecrrsponds to an MA value ot —195

‘Further spocietion on the expenment we3 thet cach tone in the
isikowoer Fternsnlztion tet tar tebe ant ta Q2alRin aa
fv, and Ther the overall spate war ton vo eaturae Fully Belo
EB Teal iw ie symirlin of 22 Pw pr tone the roe
Daision thie shone iteruenllntiss producia wil be 3 322
Dr BB AR, soos hw — l2ketRan er, ‘Tzeafore, i eas the abjonine
Df Hig West to ceduew thikonler internation below —39 Bin
with the spetied tee lo ent sion. Aad spesignion reqae
ge he ik Bye oon be soberly inorazed Tees the tebe
SA values ajith, A A

A we abl shoe, tae various amples objectives ve besa met
Tine ie w oun shady ef atnsoherin ofees npr single widsband

nutans The wore pea a 2 alent a ie
valuation ocho Tole cf low-distortign ampli ill “orm a hase
fue the detorminatar a” fealty af sing eideband tncnemigion
in morse ean lay rate

hs bale of ths poser cantina fn ne following Hors sai
Th Booker Toho east ia uf erd-boanl nsnlare ncinge, Why
in tony spe repeats infonalay wouinn? iy Bele 4 id 5
iH dns contain sow iron tle ann of 483 anaes af &
Iralenged nsion, Rituien 4 felansval syste high

interes by aie cons ratins onal Zul sdeetanding fe
te res a

oibiliy of arninoeorefealforward ample eauins, ements,
s dernmtswion nf wanpalible ar vaielenee of rious menuware
Advices interaeiag ia fesly some pacven, The very axistenoe
ff individual ssvies capable af satiivieg their sete fonctions
2889 cate vas svsimas omer FORGE, UME TL

sours be davedigeel at then Use Fabrecion murs be eben to
be predictable Whi we wulug lo sepsxste, Devine Cheines and
Experiments Rewuls ie Sei TO aad TV, we caxnot lean « folly
favovlal spin Thi lee of drsign i the last analy, am
operational proce: in Ut is eision ust take te teal astm
fperace acceptably, ua ts cu un be enn emvengeliy, Sa eval
fain etl geet pure of the pros a evign ele

‘Sect V earzmaizes che varie oslo the aly a sous
ssbis,prohtrble ara fur farhue ives

radelorwand corel, ex me tae i, kay ee mejor dhe etornies

UC reenguies tine ow and. srovides appropriate y adage

outa erent

6) Uinoris determined seletive wo tho sourve with eae suvxeive
Hage of grow. therens not al axing wny easnulaies inet
ff error othe cunt, ar abil lw sean bee
with en ever nerning wel ut lo

Tesi i rempsring Top ank apt, aloes over the turds:
sont Meine Het input nel akon sree snwranecen eens
feed, Grerufore, wok uy ah” aie eozpaxicon. La pst,

Shey ene avidly iwnttunsonn Hf rleviog speed a ar fates thom,
Iie flighty ystan, Deon epee ens te pnb,
oof, an nw falar dee, bul ov Ty £3 a mec of making
‘he evnstnw penton offedbnek aeeptatle. we were to engunize
t eysten 1" ren contol hie «id a foree fale roqulcaent of
sinllanety, not only would she pooblem. of tbrionbing aero uns
Time daviees cxapoean, but 40 wetid tho eats probes 0" aabvity
another que of the canseucuas of eompuring ireomnrabie rset

Using tar net fecture lied Zor feedforvued, ‘se reegatee ‘ho
cdasuster of trace dime m foxning « proper urn Como, Fa er
chan eomagurelapt witk ouput, we form delayed refers Jin
input whore che sims delay employed vets tamu for thy reais
ins Thome Ee sais Ut Ts anion desing fee this
ine np oll dee. Choi a the nn whe
falaved ivr i nade though «setting omer howe coming Lae
i asin On gui ayplfer Tolerrng Ps sa ier
Pato with the delet elena, we frre se ern nl tie
to the snalifier outs
Panesar oso ose

Jn having both the ampiier output sal the aeter component of
she output io fe properly rernelt the aounes hae an
Ccogruted system. Thermsvlynanical’y tne ino dinrder added to
themystern by the anpliier singe th eter Gouri proves the mesa
terverie on lo levee el wi urdu in the ample
cciput. This includes amplier distortion, undesited variation ia the
tromsfer funetion, aad therm nist. Ln the sense of dil,” the
input signal ivrmaion ennsitutes a negative ely” aud we may
fenploy Ht to ool the noise tempeeatnce of the amplifier, As inated
fn the soeond foocune of fed forwntd, iespostive of omplaity as
the syatem grows, we may fous back agai alsin 1 thi negative
futropy to keep the rytem a cool in noise teperstune se we my
‘ish

Having determized err, the nest step in the proses is to remove
the extor present in the empifd autpot. Ike prooses i, sentially
fe of subtraccicn, implemented throug «time compatible irsevferanae
tens. The deteted ere nel and ought ack to igi
trot levels ts emplierettput, Daraythe tau etd of aw ales
tion, both te signal aud eer i the ampliteroutpat are appropsitely
dala, so chct the error af the main emperor ad the arpa
Akt eros may olde rd aniblate in the ne. combining coupe.

Tr ammplfsing she drinsied eran, ela segrate e smnrot i
tooneg of che thental ose sal dios nf the even anger
fs that oreo enmeeton it nat pervert. Further te annihilation af the
‘ginal eon isimpeieet cee of wall ease tin pert
Hon within the mor cane inbeveenirter Toop. While snuck
reduesd, the rsedual sonore Aste and eianetoness may requis
frcater reuetion. Treating ths to lps comeing the cor tection
Sage as aa algorithm proves, we mit ropa that proses srbstrarly
dy ead tr nopliior atv sed of erties) anaher
‘isorloap ert ewetng sage. There i earn cero prod
by multstging sine we touch bul othe original signal, for teferene,
each sige

‘Two simplified feed-forward error control stems exe shown in
Fig. 1 following the liner of deserigtion grin abmve. Liga: Is shows
1 Auglesiaye eureetion stem, where the lems stag pes Bch
fv eeear dieting layy wy eeror revi inetdon Toon. Th ti
figure, we abetact the common panoes produce by reepectively equal
time delays. Tao main angler 's eharzterzed bya emall relative
cormples ctor, &. ‘The susiliary amlsice, refered to at times us the
rhs simpler, othe eusseetion sampler, a8 ehecueterinnl Dy
BSBA Tuy MLL see ARONA SoERRA, SOMMER
ates con 6

fa velative errr « Both of shee quantisies ago mal: ana we find the
Gatput ty five as neato evcuaccndor aallzes, onal, testvel

Figure Ih stows a uve-atage octorser eystom in: whieh che enste
Just stage ie winbedded au qaceand stage fo another tenloop exsle
of easeetion, The scot-ororesror ote org sin mage air
5 non rendered by th seoond ge alan shirdonier ere oii
an dente esion ofthe moshaning of te eeoecarealaion eeu

22 Theol Nove

Th ts use hore aka pw stage ours amplifier, thera nolan re
tuirements om the nmlier se aes se even at high evel
Neverthe, sithont apmwoprinte eatin, cherwal oie eo ine
iulverondly. breome 2 nsjor prabler ina multistage fd-foreant
system. The erux ofthe matter lies inthe specie meats by whieh we
xtrut inforotion fom the orginal soure. Lf sampling at cneh
foreeion slage depleos signal nergy vail, genie
evel neues and the reference les ts quality ae an information
ouree, To understand zh tarsal neve arports, lst ue ealeusts the
observa naive eystem with ideal error caueclission

‘A fesd-lormerdearceetion stage i zone in ig. 2 with ace souzeen
evmenaeeann eon 286,

wth.

hers

inulaed, The nenmsans sige sue Oe, Uys fy wemearnt
tho inadant. pation’ wf the ee sue, srepreively, ue waveled
tarmcnation of Use iuput eouples 8", cha nfrre! input wate of the
tain amples, wl the refered ixpu: net af te anelinry amp,
AT sr rune ial operation of both iterfermeter Ini, we may
Immediately aseoune the lle af Uy sane i i hosed ull mee
aration fn the final expt, Coieavaval ye sue eoncemed. ly
will He blackbody aca, (yaa th rsiary amplee wae, Fs

A turn “io tw bl-bp ll he tle in ell chet Fine
Selle [TS] — 1 Leck of ennyniio Whoo €, and U. proces
fforthor celta thn Te (0.403) =U

Let e cbti-url tine eorsicerstions stom ¢ , asd Ge in al that
fo.ows, stem tht. fume an i farael By tho dala esr var
"To within thar Hin, tho ingereramety ents on tbs Tes

uF Tig, Vase a flows.

SESEA + Sa = 4 a

SSR + SIPSH =u a
‘These two suussions ners ma aaapicaive in eleustion, Tey
ann, implicit, shal esher Gat Gs esslaivele, may 2 disabied

athe Tie ine ‘oa cerorminer. Wall ne teeing
ature tleetivey, clean or gain esceulaton aid ila Gy
lars enletion

Tor everall gen we 86,

m0

“Tee onuplers in Vig. Vane all dive) wa Rormuad stating, having,
the ytd venetian,
WS95 TE MLL vasa qensieAT osm, NORBERT

00 Be Me
Su Sq 0 0
Sy Su OO.

TRecare of sie Jushen win ly sie the Susteren ta
itz apie wd

(sys 1 1

819) eorfaneion #1 (8, we usin

ring 0),

sve olin dita ats i Aopen "Phe bn
iain be
Fe AGRE A HSE MROR. an
gan wing skull da sown in he Ans, wr Bad
2 ess + esi
Whe cltve mite tenn, of Uke Gea emp
se vin ave errs of he aan apr Be =
Tie ho 6 eter aur tema,
ait ”
where the rovagnilin is mele what | Sit" © — [8¢) 8 farther
‘atau Hobe fn a0
Ve tee um
Ish 18 PLS ’

"Vhs tll site: design probles may be understse ns ronnie
Teton (9) and (MN. Wa esas afer to lve tow ie of the rnin
Tiers wie geese Tt he epee ed 7 the
eu-conWaa eosin 2387

amplifier output 50 that | SH" ard | Sk | mus: be qusntitise lose to
ait. Rutan (10) stats tha oma yale of [S/n th eed
of lege maiz ample guy Gy» to Nelda spocfieg aster wai 6
If howevsr, | 83" were muade tee lares, [8°] would nsher, eur.
espunding.s, sitew hw Lv metsix elaente shane the complete
sower flow of te eoupler Sty significant reduetion of |S | ralvs
the neve temperature of the atenh, by rntue of (0), ao tha ite value
rust ho guns

‘The nike rosoncliaton with excessively lange main amplifier gain
requiremants is a2 fllewa, Main arpifier rnin det wot eer into
the final system noise temperstane in pineiple, for an iden ctor
faneclling system. ‘This holds in practier, ae well, peuvlling main
fmplifer noise is ot allows to aciave that vel wh nn mene
‘eth the dagnee of erneilation in the lst stage. In contrasting &
rmltitage erstom, therefore, we would allow tke onder of 6 dB nose
inerense por stage by making 8 |" eortspond to about 6 dl, up
tur he List stage, lasing about 7/Als gain per etege in the pres,
TTor the Int stago, teeing all previous sages ar aie, nog, main
amplifier o seven the prmees, easing Lie lial ayeten noige tem
perature to wietad fat of the let autny vanlier by about 1B,
but osing 6 4B of gsin

“Euston (8) permila & sinole, weful auproximation. “'yplelly,
[80°F deviates by lees than I poreexe ftom units ad 8! is wall
Joe than unics. 7, on the o:ter head, may range anywhere from a
silue of $ oF in practi! spaenn to el beyond HOOD, A good ap
pveimton fe 2) fe

1?
sr
vik sates th the noi tmperatare of « well-sinoeled feed forsand
yer in iver hy the nin temperature of the fal suxiary smpliier
Tine the ennai Toe fo Une eferenee ith produced by the
reference couple.

ay

4.3 Csieia for I

ste

Wor Hanes

ooh stage of sornetion requites tre autsafioitee balance The
Js, cenesponding to {l}, sets te svendards “or phase and gh of
the matin aunpliie, wile thr arcond, orn. to (2, cancels
the imbalance presets proceeding em the fea, Runiaally, the
fist -oop comparison eoupler ancl time dela closely appreciates
Ue ansicr pepertce of tae main amplifier, eo thet the ezeor signal
DAR Tu oes shox netCAE FOUMNAL, SOMEONE

due to sal toaster fasetion perorltion i small TT she standards
‘of cousin ge ad time delay ere in cll rear, the atin woul
porate io aligatly diene stwulinéa, With ite concequenze ctzer
fam © araiewhee Sight avornae power noeration of the amsliaey

rir

‘Ahersstively, invrmoi'aties cod thermal nie are rlotively
iechorwat sich respec lo The veleeaer sigaa, 90 thas they form
iar products of fe Fir ilerfoenetes lop independent o
the pression ofits bolnnos with respeet ta the eahstent parse
Ie sgl Tis the wood intevtoomneer Top Balance whieh is extcal
fn eanecling thew proven Fn te stp

‘The relative precbone of tao tw interferometry: ats, (1) aul
(@)y ne tne ewe roan eatrels diferent peimpetives i ayaten,
devign Given medeeats gmc range ofthe fal ausar aampier
the fist Toop tauet only possom hal ogre of eanetltion to avai
‘any subssnntal maniferterions of mosiacnrity in Ube asliaes ampli.
On the otter hand, the entire gure of ment of the fed-forwand eo
tovtrat ays in eleng Lieut iapmvemnt resides i she preicon
alan oe eeeaneinereumies Ip. Nor thie loop gpeeates
in oiasively light loedod frsio, the potent.al for maintaining precise
binge ie gpl, As oe bal! show, sane design effort is exuded
torearde maining « Caarindependeat asallense ef hi balance
rough the we of euslary corse.

2 Pit-Stays Poo

Witkin a feelorwand merous etn we aaa ack sceeptabe
choices of microwave tmplier mess af wroommedating relatives:
Tesye tine delays couplers tpl’ ta the needs of precision intr
feconsetey,adjurtaent meu fr erp, adplivecontolers to maintain
fimeindstendent operation, she. The adjetive “acceptable” suggests
fot only the wo of deviers vyuble af aneting ster teenies! ob-
jectives but implies objotives ax well, of ultimste reprodneiiity,
ume marital sompeet pekaging.

‘While, nthe lenge loom, sol think of rierowave ioe

of maay ofthe vonnpiente non a tbo austin svete, atration
Fsiveompurs nih tw frimodiats reeds of «fest densnstetion
‘The wierownse eacerinent, therefore, was perferzed entity vith

svvexnice wid einai eeouiey ta proved> Zor ons of rnd iention,
Ti govoral, a wis lnone eneesperdenee axsts bute a se