Nigute ushobora gusobanura no kubara dB, dBm, dBw… ni irihe tandukaniro riri hagati yabo?

Nigute ushobora gusobanura no kubara dB, dBm, dBw… ni irihe tandukaniro riri hagati yabo?

dB igomba kuba igitekerezo cyibanze mu itumanaho ridafite umugozi.dukunze kuvuga ngo "igihombo cyohereza ni xx dB," "imbaraga zo kohereza ni xx dBm," "inyungu ya antenna ni xx dBi"…

Rimwe na rimwe, iyi dB X irashobora kwitiranya ndetse igatera amakosa yo kubara.None, ni irihe tandukaniro riri hagati yabo?

Ikibazo kigomba gutangirana na dB.

Iyo bigeze kuri dB, igitekerezo gikunze kugaragara ni 3dB!

3dB ikunze kugaragara mubishushanyo byimbaraga cyangwa BER (Igipimo cya Error Rate).Ariko, mubyukuri, nta banga.

Igitonyanga cya 3dB bivuze ko imbaraga zagabanutseho kimwe cya kabiri, naho 3dB isobanura igice cyimbaraga.

+ 3dB bisobanura gukuba kabiri imbaraga, -3Db bivuze kugabanuka ni ½.Ibi byaturutse bite?

Mu byukuri biroroshye cyane.Reka turebe formulaire yo kubara ya dB:

dB yerekana isano iri hagati yimbaraga P1 nimbaraga za P0.Niba P1 ari kabiri P0, noneho:

niba P1 ari kimwe cya kabiri cya P0, hanyuma,

kubyerekeranye nibanze shingiro nibikorwa bya logarithms, urashobora gusuzuma imibare ya logarithms.

[Ikibazo]: Imbaraga ziyongera 10time.Nangahe dB?

Nyamuneka wibuke formula hano.

+3 * 2

+ 10 * 10

-3 / 2

-10 / 10

+ 3dB bivuze ko imbaraga zongerewe inshuro 2;

+ 10dB bivuze ko imbaraga ziyongereyeho inshuro 10.

-3 dB bivuze ko imbaraga zagabanutse kugera kuri 1/2;

-10dB bivuze ko imbaraga zagabanutse kugera kuri 1/10.

Birashobora kugaragara ko dB ari agaciro kagereranijwe, kandi inshingano zayo nukugaragaza umubare munini cyangwa muto muburyo bugufi.

Iyi formula irashobora korohereza cyane kubara no gusobanura.Cyane cyane iyo ushushanya ifishi, urashobora kuyuzuza ubwonko bwawe bwite.

Niba wumva dB, ubungubu, reka tuganire kumibare yumuryango wa dB:

Reka duhere kuri dBm ikoreshwa cyane na dBw.

dBm na dBw bagomba gusimbuza imbaraga za P0 muburyo bwa dB hamwe na mW 1, 1W

1mw na 1w ni indangagaciro zisobanutse, bityo dBm na dBw birashobora kwerekana agaciro keza k'imbaraga.

Ibikurikira nimbonerahamwe yo guhindura imbaraga kubisobanuro byawe.

Tugomba kwibuka:

1w = 30dBm

30 ni igipimo, kingana na 1w.

Ibuka ibi, hanyuma uhuze "+3 * 2, + 10 * 10, -3/2, -10/10" urashobora gukora imibare myinshi:

[Ikibazo] 44dBm =?w

Hano, tugomba kumenya ko:

Usibye 30dBm kuruhande rwiburyo bwikigereranyo, ibisigaye bigabanijwe bigomba kugaragara muri dB.

[Urugero] Niba imbaraga za A zisohoka ari 46dBm naho ingufu za B ni 40dBm, dushobora kuvuga ko A ari 6dB iruta B.

[Urugero] Niba antenne A ari 12 dBd, antene B ni 14dBd, twavuga ko A ari 2dB ntoya kuruta B.

Kurugero, 46dB bivuze ko P1 inshuro ibihumbi 40 P0, naho 46dBm bivuze ko agaciro ka P1 ari 40w.Hariho itandukaniro rimwe M, ariko ibisobanuro birashobora kuba bitandukanye rwose.

Umuryango rusange wa DB ufite na dBi, dBd, na dBc.Uburyo bwabo bwo kubara ni bumwe nuburyo bwo kubara dB, kandi bugereranya agaciro kagereranijwe.

Itandukaniro nuko ibipimo byabo bitandukanye.Nukuvuga, ibisobanuro byimbaraga za P0 kumurongo biratandukanye.

Mubisanzwe, kwerekana inyungu zimwe, zigaragara muri dBi, ni 2,15 nini kuruta uko bigaragara muri dBd.Iri tandukaniro riterwa nubuyobozi butandukanye bwa antene ebyiri.

Mubyongeyeho, umuryango wa dB ntushobora gusa kwerekana inyungu no gutakaza ingufu ahubwo unagaragaza voltage, ikigezweho, n'amajwi, nibindi,

Twabibutsa ko kugirango tubone imbaraga, dukoresha 10lg (Po / Pi), naho kuri voltage nubu, dukoresha 20lg (Vo / Vi) na 20lg (Lo / Li)

Nigute ibi byikubye inshuro 2 byaturutse?

Inshuro 2 zikomoka kuri kare ya formula yumuriro w'amashanyarazi.N-imbaraga muri logarithm ihuye n inshuro nyuma yo kubara.

Urashobora gusubiramo amasomo yawe ya fiziki yisumbuye kubyerekeye isano ihinduka hagati yimbaraga, voltage, nubu.

Ubwanyuma, nubahirije bamwe mubagize umuryango ukomeye wa dB kugirango ubone amakuru.

Agaciro kagereranijwe:

Agaciro rwose:

Kandi, reka dusuzume niba ubyumva cyangwa utabyumva.

[Ikibazo] 1. Imbaraga za 30dBm ni

[Ikibazo] 2. Dufashe ko umusaruro wose wa selile ari 46dBm, mugihe hariho antene 2, imbaraga za antene imwe ni