Hanya ta zamani a matsayin hanya na watsa bayanai

Kamar yadda aka sani, da RF siginar kunshi wani m, wanda dogara ne a kan igiyoyin rediyo a cikin nau'i na sauki masu jituwa oscillation u (t) = U cos ( ωt + φ). Ya biyo bayanan cewa akwai sigogi masu zaman kansu guda uku a cikin siginar mota, wanda ya shafi abin da za ka iya kama canje-canje a siginar sarrafawa.

Wannan yana nuna yiwuwar nau'i uku: amplitude (AM), mita (FM) da kuma yanayin zamani (FM).

Phase daidaitowa - mai Hanyar watsa analog ko dijital bayanai ta canza na farko kwana (lokaci) φ ₀ da m mita na daukar kwayar cutar sigina.

Da shi, lokaci φ (t) ya dogara da amplitude na sigina (modulating) sigina, wato. φ (t) = ω _{0 t} + _Δ φ _∙ sinΩt + φ ₀ = = φ _{0 +} ke (t), inda k - proportionality factor.

A lokaci-modulated siginar da aka kullum aka bayyana da magana u (t) = U _n Zunubi [ωt + φ (t)].

Lokacin da daya sautin daidaitowa [e (t) = E zunubi Ωt] muna da: φ (t) = φ ₀ + Ke zunubi Ωt = φ ₀ + Δφ _max zunubi Ωt.

Bayan musanya da dabi'u na φ (t) a cikin lissafi na zamani-modulated sigina mu samu u (t) = U _n zunubi (ω _n t + φ ₀ + Δφ _max zunubi Ωt), inda Δφ _max - iyakar canji a lokaci gwargwado ga mawadãta na kula da irin ƙarfin lantarki. Δφ _max in ba haka ba ya kira kwana daidaitowa index da aka denoted ta m.

Kamar yadda za a iya gani, a lõkacin da FM m = Δφ _max = Ke. A instantaneous darajar a lokaci-mai sãɓãnin lokaci kwana Θ (t) ne daidai Θ (t) = ω _n t + φ ₀ + msin Ωt, don haka da cewa ω = d Θ (t) / dt = ω _n + mΩ cosΩt, a cikinsa mΩ = Δφ _max ω = Δ ω _n = kEΩ - iyakar mita sabawa for FM ω _n, shi ne kai tsaye na gwargwado ga amplitude da mita daga cikin modulating oscillation.

Ta haka ne, tare da FM, nau'in fasalin da ke nuna iyakar canji na zamani ya dace da amplitude na siginar sarrafawa kuma bai dogara ne akan sauyawar mita ba. Canje-canje a matsayi mai ma'ana da darajar (darajar) ya bambanta kai tsaye a daidai da amplitude da mita na wutar lantarki.

Dangane da yanayin aikace-aikacen, yanayin zamani yana da nau'o'in iri. Ɗaya daga cikinsu, musamman ma, shine zumunta ne na lokaci.

A cikin wannan tsari, dangane da siginar haɓakawa, kawai lokaci na siginar ya sauya, kuma ƙarfin kuma ƙarfin jigilar bazai canza ba. Tare da OMP, bayanin darajar ba shine daidaituwa na lokaci ba, amma canjin da ya danganci darajar da ta gabata.

Hanyar lantarki wanda ke haifar da canji a cikin kwanakin lokaci na oscillation (wanda ya haɗa da wanda ba a haɗa shi ba) daidai da siginar haɓakawa ana kiransa fasalin lokaci.

Yawancin nau'o'in irin waɗannan hotuna an ci gaba. Makircin mai sauƙi mai mahimmanci yana dauke da varicap-diode, wanda zai iya canja ƙarfin haɗakarwa a ƙarƙashin tasirin wutar lantarki. A cikin wannan makirci, wutar lantarki na canzawa ta canza canjin varicap. Tsarin lokaci yana dogara da girman girman karfin wannan diode da juriya na juriya R.

Sabili da haka, wannan motsi ya dogara da wutar lantarki. Wannan yana ƙayyade yanayin zamani na siginar rediyo. Duk da haka, irin wannan motsi ba shi da alaka da haɗin lantarki, nauyin haɓaka yana da alaka da nauyin lantarki, wadda ke haifar da ƙarin matsaloli a cikin gina masanan zamani.

A cikin tsari mai tsabta, ba a yi amfani dashi ba don amfani da mahimmanci mai mahimmanci - ƙananan rashin lafiya.