Wajiga isbedbeddelka sidii hab ka mid ah gudbinta xogta

Sida la og yahay, signal RF ka kooban yahay side, kaas oo ku salaysan hirarka radio qaab fudud oscillation harmonic u (t) = sababtoo ah U ( ωt + φ). Laga soo bilaabo tan u socota in signal inta jeer side, waxaa jira saddex-beegyada uu madax-bannaan, oo saameyn ku qorid, kaas oo beddeli kara signal gacanta.

Taas oo muujinaysa suurtogalnimada ah saddex nooc: Ilodanimada (AM), inta jeer (FM) iyo isbedbeddelka wajiga (PM).

Wajiga isbedbeddelka - hab gudbinta analog ama macluumaad digital by beddelo xagal hore (wajiga) φ ₀ inta jeer side of signal u kala qaado ah.

Marka φ (t) wajiga ku xiran tahay gacanta Ilodanimada (isbedbeddelka) signalka, i.e., φ (t) = ω _{0 t} + _Δ φ _∙ sinΩt + φ ₀ = = φ _{0 +} ke (t), halkaas oo k - factor saamigal.

signal wajiga meyxaanahaa waxaa guud ahaan ku tilmaamay by muujinta u (t) = U _n dembi [ωt + φ (t)].

Marka hal midab isbedbeddelka [e (t) = E dembi Ωt] waxaan leenahay: φ (t) = φ ₀ + ke dembi Ωt = φ ₀ + Δφ _max dembi Ωt.

Ka dib markii lagu badalaa qiyamka φ (t) ee isla'egta of signal wajiga meyxaanahaa aan u (t) = U _n dembi aad u hesho (ω _n t + φ ₀ + Δφ _max dembi Ωt), halkaas oo Δφ _max - isbedel ugu badan ee wajiga saamiyeed si ay Ilodanimada inayan ee danab gacanta. Δφ _max haddii kale loo yaqaana xagal index isbedbeddelka oo waxaa muujinaysaa by m.

Sida laga arki karo, marka m FM ah = Δφ _max = ke. Qiimaha degdeg ah ee xagal waji waqti kala duwan Θ (t) waa loo siman yahay si Θ (t) = ω _n t + φ ₀ + msin Ωt, si ω = d Θ (t) / DT = ω _n + mΩ cosΩt, kuna waari dhexdeeda mΩ = Δφ _max ω = Δ ω _n = kEΩ - weecasho inta jeer ugu badan ee FM ω _n, waa si toos ah saamiyeed si ay u Ilodanimada inayan iyo inta jeer ee oscillation u modulating.

Sidaas darteed, markii index isbedbeddelka FM ah sifeeyay isbedelka wajigii ugu badnaan waa saamiyeed si ay signal gacanta ku Ilodanimada oo aanu ku xiran tahay inta jeer isbedbeddelka ah. kala duwanaansho ayaa inta jeer ee ku saabsan celceliska (weecasho) waa si toos ah saamiyeed si ay u Ilodanimada inayan iyo inta jeer ee danab modulating ah.

Iyada oo ku xidhan isbedbeddelka wajiga codsiga uu leeyahay noocyo dhowr ah. Mid ka mid ah iyaga ka mid ah, gaar ahaan, waa Keying a Shift kala Phase.

In foomkan, taas oo ku xidhan signal modulating ku kala duwan yihiin oo kaliya in wajiga of signal ah, iyo inta jeer iyo Ilodanimada inayan sii joogto. Marka qiimaha macluumaad RPM ma aha isbedelka wajiga waadaxa ah, oo ay kala duwanaansho la eego qiimaha hore.

circuit Electronic, kaas oo keena isbedel ku xagal wajiga of oscillation u meyxaanahaa ah (marka loo eego side unmodulated) iyadoo la raacayo signal modulating waxaa lagu magacaabaa modulator waji.

Horumariyo noocyo badan oo ka mid ah images. Scheme modulator fudud ka kooban a varicap - diode awood hoos saamaynta beddelo capacitance gacanta Isgoyska danab ku. In nidaamka this, modulating danab u beddelayo dhismaha awoodda waxqabad ee varicap ah. wareeg wajiga ku xiran baaxadda qaraabo ah diode capacitance iyo R. iska caabin Xamuulka

Sayidka, shaqada waxay ku xiran tahay danab isbedbeddelka ah. Taasina waxay keentaa in isbedbeddelka wajiga of signal raadiyaha ah. Si kastaba ha ahaatee, wareejin noocan oo kale ah waxa uu la xidhiidhaa capacitance a Fansaarada danab modulating varicap la xiriira danab ku Fansaarada modulating in abuuraa dhibaatooyin dheeraad ah ee modulators wajiga dhismaha.

isbedbeddelka wajiga saafi ah ma helin codsi ku filan ballaaran sababta oo ah khasaaro halis ah soo jireenka ah - difaac buuq yar yahay.