Danho vachisiyanisa inzwi sezvo nzira date hutachiwana

Sezvo chikazozikamwa, kuti RF Mureza chinosanganisira mutakuri, iyo yakavakirwa paredhiyo mafungu muchimiro nyore harmonic oscillation U (T) = U Kosi ( ωt + φ). Kubva ichi zvinoreva kuti ari mutakuri kakawanda chiratidzo, pane vatatu akazvimiririra parameters, kukanganisa rupawo zvinogona kushandura kudzora chiratidzo.

Izvi zvinoreva kuti tinogona matatu mhando: amplitude (AM), maitikiro (FM) uye danho vachisiyanisa inzwi (PM).

Danho vachisiyanisa inzwi - nzira kuparadzira analoginen kana digitaalinen mashoko nokuchinja kwokutanga angled (danho) φ ₀ mutakuri kakawanda chiratidzo zvitange.

Kana danho φ (T) kunobva amplitude kuzvidzora (vachisiyanisa inzwi) chiratidzo, i.e., φ (T) = ω _{0 T} + _Δ φ _∙ sinΩt + φ ₀ = = φ _{0 +} ke (T), apo k - proportionality chikonzero.

The danho-modulated chiratidzo unowanzoonekwa yakarondedzerwa okuti U (T) = U _N chivi [ωt + φ (T)].

Apo mumwe matauriro vachisiyanisa inzwi [e (T) = E chivi Ωt] tine: φ (T) = φ ₀ + Ke chivi Ωt = φ ₀ + Δφ _Max chivi Ωt.

Mushure dzinomiririra zvinokosheswa φ (T) munyika mukana wokuti vanhu vanga vari Pasika-modulated chiratidzo tinowana nepfambi (T) = U _N chivi (ω _N T + φ ₀ + Δφ _Max chivi Ωt), apo Δφ _Max - kunonyanyisa shanduko chokutambudzika Proportional kuti amplitude yacho nokudzora voltage. Δφ _Max zvimwe inonzi angled vachisiyanisa inzwi indekisi uye runotaurwa m.

Sezvinogona kuoneka, kana FM M = Δφ _Max = Ke. The nguva imwe Kukosha yakaipa nguva-danho angled Θ (T) akaenzana Θ (T) = ω _N T + φ ₀ + msin Ωt, saka kuti ω = D Θ (T) / DT = ω _N + mΩ cosΩt, sezvamakaropafadzwa mΩ = Δφ _Max ω = Δ ω _n = kEΩ - kunonyanyisa Frequency kutsauka nokuda FM ω _n, ndiyo Proportional kuti amplitude uye kakawanda pakati modulating oscillation zvakananga.

Saka, kana FM vachisiyanisa inzwi indekisi zvinoratidza kunonyanyisa kutotanga kuchinja Proportional kune amplitude kuzvidzora chiratidzo uye hakubvi pasi vachisiyanisa inzwi maitikiro. Kakawanda kusiyana pamusoro Zvichakadaro (kutsauka) ndiko Proportional kuti amplitude uye kakawanda pamusoro modulating voltage zvakananga.

Zvichienderana chikumbiro danho vachisiyanisa inzwi rine mhando dzakawanda. Mumwe wavo, kunyanya, ari Differential Pasika Shift Keying.

In chimiro ichi, zvichienderana modulating chiratidzo dzinosiyana chete chokutambudzika chiratidzo, uye kakawanda uye amplitude kuramba kugara. Kana RPM mashoko mutengo haisi Mhedziso kutotanga shanduko, uye kushanduka waro panyaya yapfuura tsika.

Electronic redunhu, iro rinoita kuchinja Pasika yorusvingo of modulated oscillation (hama kune unmodulated akaendesa) maererano modulating Mureza inonzi danho modulator.

Dzakabudirira Mhando dzakawanda zvifananidzo. Scheme nyore modulator unotora munhu varicap - diode anokwanisa pasi mugumisiro kuchinja kudzorwa voltage Junction capacitance. In zano iri, modulating ari voltage anochinja vanokwanisa pakati varicap. The danho kusuduruka kunobva hama pamwero mukuru capacitance diode uye mutoro kuramba R.

Saka, chaishanda kunobva vachisiyanisa inzwi voltage. Izvi zvinokonzera rimwe danho vachisiyanisa inzwi pakati redhiyo chiratidzo. Zvisinei, kuchinja kwakadaro Rinobatanidzwa ane nonlinear modulating voltage varicap capacitance yakabatana nonlinear modulating voltage kuti pave mamwe matambudziko pakuvaka Pasika modulators.

danho Kwakachena vachisiyanisa inzwi haana kuwana zvakakwana paupamhi kushanda pamusana wayo yokusafa zvakakomba chinetso - yakaderera ruzha kutapata.