BSTJ 50: 7. September 1971: TH-3 Microwave Radio System: The IF Main Amplifier. (Fenderson, G.L.)

3.8 MB·English

Sha

TH-3 Microwave Radio System:

The IF Main Amplifier

By GL, HENDERSON

(ass nev Feber

{The LF was wages ia the pet amine for the THB erase
vero recier. The amplion proton @ 3 fo 49-4B ges range wvtor
ik AGC ita to eamponsot or ea aig ai
tira eth eater Frequency nf 0ABHE wh
teenly ft trauenioson chacectrce cer @ 83-0 7-36 Hl bad.

‘Ve THL-# TF man apie” provides wn ontpt of 4 dBm al
ronmelly operate nn ten of 84D, Cader ego] uf sa AGC eal,
this gain crn be iewwesee ta 49 elb or eevee to Tes then 9.
"The amplifier we tea eileen trsistare i fse gain legos an sb
silicon trvvsistir in the AGO elceul Figure 1 stows the block
febematie of Uie amples "here aze five phn sagse in tacems to
provide tne AAD mnaxisuan gain, The she iseewsediaceetegee are
‘yatighle gin in provide the ta guia range

"The desien objective for the emplier was 6 Net irgnsiasen and
Altay ehapaeterie aver the §8- to 8P-Ms hin. Gin devistions of
Teas she D3 dal dla seetion of ess than 0.21 were sie
Ivorder tao have objectives 2 las gain ste we neoded waving,
very ase broaden trateivion charaetenetie. Uther dese
fharacteristee were: ss} se 0° Weck to obeain guix tail,
{if tutor gain control expabil ies wih the use of a singe ¥
tle elem st (9) negligible inleraetion between etages to Sneli-
fave easeeding. The wee of traforusi was coe avoided due tothe
warinbty uf erste requeavis, This hese gen stage could
hea be use sigh the easy reeter where IF auspiieabion wae
rezired,

hls goin fas wk in ots an af trates bag?
for eB oa
2195 ym REE SYRTEW THC, JOR, SEPTIOCRRR 16

een 28h 238 i a ; eon
Ly >
oo
Tee Oo ORS

ig Bleck veo of LF maa apie

‘The bacie gain stages developed saw shown ix Fige 2 end a. They

sve series-eburh “ambaele pain having a low inp ir pecaner and
fmplayng bot an end. 9 Frac: tn taitetn gain and bike ene
Iilty. Te Toad may be oosnreve te ether Pie emo, sowa in

Fig. 2, or the collovior us shuns in Fig, 3. Buch conaeetion bee
prefered aren af wsefunoas. Thecmniter-npie load enmneetion as
leche for the TF anpliter setion Deeaive of ity Beller Linea
‘The uutont iupedonne urvle> ie ein i very Taw dus to the
hunt feezoace, The oollestor-enuptn’ lone. connection ‘wre eelectad

Ny
a sats anon 2197

Fig. 3 Colleton cous Ne on sn.

for the monitaretage enue uf qe ifletion Sete a!
buipul. The ent ipedense ure ie wonion 3 wery “kage Sue
to she series Teethick, (Uther stents which uso this basi gain stage
fate the Fries amplifier, the squeleh ovtintor? awl the 4A EBT
terminate?

‘The ttansmicvion mponee of clther cho emitter-oupled or the
colector-eouplot! sage i given by & qoute nant of the form

ast
where 5s comyiex forqueney ana ty, el are oonatants which
Teperd on che viruit paranters. Wien Hy =, te 80 open loop
poles ave roa! nd ec loeated ox the negative real as ne shown
Fa, As fe ie erensed fhe putes more along the sais fly met
fd then fos empl conjugal pate. Further motin i along a Tine
pcalle withthe jo sea idieated. When cho poles mneh pins such

w

os
2108 sau» wets aveemoe aronsieny sooRA

‘thet tines extended to the origir form 46~egroe angles with the rol
vin, a masinelyft-mnagritane-esporee ves, Tv uh presence of
upiing wad Bypassing expncera ie ignored, the arpter ist lok
pee strucre having bendigts equt) to the disteaa between 4
pols and tho origi. Per thr eximirg eireuit parcictars this bandwidth
Js grater than 200 Mile, Some dilferences in bandisth occur bo-
fimeen an eniter-eoued nd a eolletor-eoupled etage depending on
Ue magnitude af the eollectar logs impedance due to the Miler
‘upabitance ele, These diierence, however ave sll f ube elleolor
Toul iepesdane i eal, a woul? the ease n onsen aps

“Asst ng the ofseloup wal args the lose Tn gx Zor the
emier-oupiec stag is

he e
iT a
Since the eallerior current. contains the shunt feedback: eurrent the
lowly yan for che rtiesonscoupled lage ik

e

For both cteuile Ry it stewed Tor « Bah ietneniaion eha-aceratio
ad Dy is elated for tne desnedguix. Sac the emiter of QB is very
=aurly a zao-ipodance poi dvt 20 the stunt fcuk, Ita ay bo
varies rithewe churging the value of che feodatck current signif
cantly. This allows vetiation in gain without affecting the tranamis-
lon response. fy may be & Guat resisar for a fxd gun stage or 8
{lode fora voage-cantroled vette gin etogo. Thos the hes gain
‘agg has iin anna gain coll eapaalitiee wih the im of
tingle varinhle clement.

‘Pao Wide selected forthe vorm ble adn stages isle WIRATAA. PLN
ioeo? ‘hie dhe citer trom fe standard LN yusetion aide by &
Iyer of insinee son betraen the B and N type alloen, Iho tee
irtunce of che L-uyer ie controlled ky the direct eurrent Aewing
through it by the process of concizeiity tmodalution, and is indee
Detdent of tbe instantaueous variations of the LF algal due tothe
Jong eanet tse and long life time af te insted eazree. Then re
ai requrvcies shove which the jonctian iepedance (whi i Cee
(queney depesdots} is small eamprced to the [laser impedance, the
PIN dioce wes as < tnqueney independent ese ceetemee whoee
elie is oontalled ty the dient ourent. Fighsve & ard 6 show the
‘ovmall‘tanemiseon cbaracorelic aul Ue aehemaliedigeraa of the
a pany sbnseren 2190

‘Pig $ Travan sara of TF sa amie.

main ecpliie section wsing the exfvtr-eont asic win stage
‘Pwo PIN clos exe ised 'n estes for each yaricble goin stage 10
tuinimige she eee: of the dinde exunt expaciane

Tout aul output topeduies of 72 obras are uleinad by asing &
feviee revisor anil tone eaparitors aos 2g The insak aeage
Ses au codtone| resner in eeien wit ne rpitar€o fea a ee
San valance novvork whieh eaales in « liglly Decter recs le
Reus? Ines givater Une $0 JB are achieved using fais cype 0”
tnetebing, See the ersit-eridange a i op stg is ed hy the
ecu Joes reciersert, the desived gin is obariaed hy yrnper selece
fion of the feabark rsister, The value rqnized to obtain 4 dB of
fein celle in positive ope arrose she TF and An jus soiet
TRG network ts provi athe ipl Ly le sage as shown i Fi
tw ence forte signe ant sorgcel (or inar transmission vetiae
tony in the temtinde” uf Use amphfer, With thee adjuesents th
tranmnission eneaceristic ean be adjusted Uo be Mat within O01 dB
‘Over the - ¢o 87-MPr TF lsd. ‘Te delay i evel ft (thin
emiting accuracy of Os ne} aver the hand wich a value of 108 ns
i norm goin. "The deloy ieresees to woot 12 sa 49 0B gain.

The synal levels throughout the amplifier ace elected ana ome
promise letween nce Agus, AM/PAL conversion, wl ani die=
Tovion, or beet Unermal noes performer the signal evel wiZhin the
hmplifer ehould te ss Sigh ae porsble Convrine'y, ABM and
Theos distction nn minisita Yr low sig evel Foe thie zeacor,
only m rail smouny of gain (8 ol) ns! aoa ofthe fst vaxiabie
2200

(Shit

wy

AL

at
3
rw ss saat 201

ein sage ‘Tis nectts wen swonal mice gare of about 12 els wher

he emp idar ix wpering 2 minal yan 9 AB). A ploe of noise
igo fraps gain is shown ja Fig. 7 Ako rhosu in Hg. 7 e the
AM/P3C conversign st ie suo wa! tind harmosiedietoreion at
fvanipu pomer nf 2Bra, Tacuiite euse cease etion nase

fs TM syclonm ly eochining ma fellow sen inary oo Tara
flayed fasanonte) similar 2. LF eee. suze wala
frectes 3p prov-uus Un sins'tu flviacone, canes exer,
yee and Marvand splice dstertin wien nomeased In PM By
tn AM/PM eonveirirn! Derign shjrcves dar soa saennelere were
EEermonieto-fularrial power rete are than 85 dM nud AM/PM
ouvert of ces Hl GA cigtens TR asesured <& rove! gain and
Suapat omer. Za meds thee objselives forthe given Fignal evel ca
Sivas, the tnt ond second swrwitor af eeeh fenbErk pale wee
Uist wi ves, ane a 6 vo ts SP ma rsp

“The 45B, C, ai H niavssxare whie= ars eel ice out af « fuily
oe higetrequcuey planar, eplcaiel, NPD sean semantes wis ce
‘anaceriaad yn 1-GFezsin hare peorset> ‘Te SIP isa

oe — a
i 4 by
4 pais.

Tie TAAMGIPD exorcised canis Ueto TP nn
S02 aut anc svevEAC BOREAL OER, SEERRUNER 71

lar tothe 45C except for & aus bese oslatonce which vets in
lswer may Biguoe, is vein tl foe fuzadstor of che
fet chnes ‘eedbuele pers to beip uncle noise Rzare elit

A sohematis of the ACC erst: i aguas m Pig 8. Byerp fr the
toon nr ange {QT aid 12) and the cbarner of em II fer, bis
upier is sin ilar oy Hy AGE. amoifier deeribes a Ret. 5. The
speten funn: ies ches nf the TF anain aol: i red upon
fo prose! wipro srs nn aTeeing te AG. regulon,

“Pre nnvitorseege faa eallomar ou seit feaack pair
‘This stags iolaea the deteroe Hodes Cone the TE ectout stage and
prosiler 10.4R of smpliieation, The UF sips! i tected ty the
Aetcetor dite va syle ony achovescage diferent de alien,
he A eve eztv! haa Ue le af 14 to ta ache ena
boner of the auzlifer fy adjvating she reference votags. A dicds
lostca: 2p fia celular dole balan ise ve provide fezpennture
ovrpeneesion, Ue wtering rewire he ou;pub a she de sper
ie uses to anaes rave grad Yoel. Trarastar QUO prorden &
tidl-ingearee aczzee wits wich to dvve the PIN dees. Aa shea
2 Fie. sor Ine gra iz Jango enoug 1 re-rie. tle aout bral
aniation ovct the Ave fae stage co 06 US, Sui SU apne So de
feedback loop to allow manua’ gaia adjurtmen: for ewes vtic pur

Figioe 10 stows & phovesrnih of the sit cxpliier sad ACC de.
fit heed in an acum ovsing, Tig 245 % 20 irckee* Three
Svenate print! edruit aes we Tor the OP amplifier, AGC
‘oni ensanster network, an supply wattage dite.

1 ine 6, Mone Re Se: oso” 3 hn
st safle Ty Lone 8 aad Slee, BC, “TH Vener Tao
‘ogra ad Wi Buide ted sete” BAF Ibs ey

foe 1, goin Sei ce Bex” IDS lize Role Sa
4 cm Gh vanities fa Fad Soe uu

gender 8 "At Upto oy Toe
‘Kepler SEG pp 105-18 a

Sie bie dese mar done by. BL lel
vet
Hi 5

ib
2004 ru may sismmar suenmtean soca, eTENSRR TY

Fig, WIP ee pls