VNaT—IL Angle Modulation ek Pnboducten : P a Mn amplitude modulation, ta amplitude x e Carer fs Vawied according to te amplttude 3 the modulating Aiqnel - Tn angle wodulahion, te piequoncy ov phase % tue Carticy ts Varied according to tte amplitude 2 the modulabng- Cbmal: allen inyorwration ouiqnal ued to vary Ha pfequerrery Dy cavviey aiiqmal ,we have prequesey modulodin- On Hue olber hand, wlan {ngor maton Mienal fs usted ty vary thee curgle + Cantey wianal, we have phase modulation Instead % corr pit cy either peqerey ov phase » the odinuwidal cartier con be changed according fp Hee menage , Keepiny Hu amplitude constant This Metlrod 2) modulation termed as ‘angle modulation” oe Concept Py Phase Medutatien : When phase a the cartier Varles in accordance with Hue Mmetiage waned m(t) ey Lor mit) B=kpm[t) oO iio Kp is Propo Renal; fy constant ov phase wonsi BV D, modul ator =D vod | Ke “mit) (4) Th eagtertion PM signal can be caprened) em Hee angle modulated wove i-e-, SUD= Ne 05 0 = Ae Cos (Wer P) a) cS ee: is an ee Os a eae lies Ce PAM COS Wyte PS aban Fader, Baer pL binutoided, ™ [t) = Ae, cos mt s Scanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerScanned with CamScannerGeneration Hy FM Bignal Eri Armstrong We Kool > af 0 called as Thes mettod fs “al Lndivect mettod: In the Armshon method , fequerey autability ‘ tox By a biqey oxder can be obtained becouse Hu caystal Se us Con be uted as 0 Cavriew apveretor The basic principle ay method §8 40 ofuerote a harrwdbond FM (NBFIN) indirectly by fing He phase - modulation technique , and tien converting t's AGFR b a wideband FID (WeFM) ‘The distortion is 100 “in N@EM as the modulshen fndex fs Amal The phase rodulotinn is. preyerred because 3 ts easy qeuurotion schemes: The ue “Fen The multiplier circuit ,apovt prom multiplying thee carey frequencyy, alio Increases the prequency deViat?en and Hus the NBEM (aumall deVintinn) 75 converted Gnto WGFIM (large deviccton) * 2 po xofe|2 Ht cy Dae Coety ‘feye2oikdy — Dfe* Fcy=4 0m a Br e2shy, ! Joa te crt | Fer | Nowip? ia Fr se er inlet eek cake REE Pm fi meee] © | foe am pli We Nj, 248 Fo3=90[y8 = (44H DFS KH YY i cyt ma sbi Ltoamt ae tg F194: Blick diagiom Ban Armshona Fm Tronsmtttey The multiplication proces ‘is perqprmed fin aeveral aloges fe ordex to Increase the. caxticr pregency as uel as ree) aa deviation t Hla amiqned vole - The desired rlylanion tet f cavrien Tee and eptennetey deviation are not tte same « Pie ses ata "s done tn me whot, he carries Teqeney as 7 a the deviation ‘ts multiplied by fle same. qocty which fyScanned with CamScannerScanned with CamScannergoct Hob distortion «The nm-—lineoxth, fs Obvious, 5re™m He m neat ty i soy E We dilege is nob the same ab every point % ee chore ~Yistics - 4, The (ttotien (Rm=linearhs) 1s removed = Bf Alay a tagger - bined Lc circuits (balanced wope detector) « + Balanced wlope Dechy The two tuned circufts ave fn the tuned mode icy ene fs tuned above fle caxrvict freanenery Wo wnd the Ofer ts tuned below 4%. + the resultant curve 1s linear a5 wlan by the dotted Gre Thus no harmonic distrrtion i caused wt tle operotion is restitcted 4 Hie linear veqion: sitaqger - al Waar FiqiChreuit dioqram a a Balanced Slofe Detector Disadvantags m% the Balanced Slope - Piscrtminator * 1) The Uneor chatacteristic is limited to a Gmall preqneney deviation (DF) The frequency deviation [A¥) 4p | lich, We resultant characterise is linear depends m the 348 bandwidth a cach ‘tuned circuit sohieh is equal 40 Qu: He. linearity. is lited) ty a TT ; As aScanned with CamScannerScanned with CamScannerScanned with CamScanner€ Comparison ty AM and FM 3 ) Noise ferformance ‘ In the low-noise case, wideband FM has a better noise ferjowmance thon Am: The greater the banduidth, better ts Hu notice Perpotmance - On He contra, fn te lave -nofse case, Am 2s better Hien FM becouse He Wound due + tu Hneshold eppect fh FM appears ot a higher (S/n)retio than tn ANN 2) Comme Channel Thteverence % FM fs better Han Am, because % capture expect The Tnlevfering weak signals receNed Vow He Ndighbouriing chonnels axe Heads Completely. auppteried in FM, but produce distoition: in AM 3) Channel Bandwidth : The wideband FM has o lorger banduitd th a8” compared to Am because Hue former produces a larger number dy idebandls: In o typical broodcast wy stem, cach channe| bandwidth in’-Ain ts isk; , whereas tn FM it fs USOKH : Tereynre ,FM hos a disad vantare Over AM-Tha qiven pony Mpace, FM accemma@dates les number % channels as Compared to AM YF) Dferatina, Canrier Frequancsy : FM utilizes higher carrier poquney (above SONU) because 2% its higher bonduiidit Dy Fm fe used at the lower cartier frequencies , channels will be too Sess: 5) Transmission Exficteney, « FM bas more efficien the number 2 Avoilable eo Khan Af. Te fhicience- 3 He Aopretted carer. AM is better thanScanned with CamScannerScanned with CamScannerScanned with CamScanner