Indlela yokucacisa nokubala i-dB, i-dBm, i-dBw…yintoni umahluko phakathi kwazo?

Indlela yokucacisa nokubala i-dB, i-dBm, i-dBw…yintoni umahluko phakathi kwazo?

I-dB kufuneka ibe yeyona ngcamango isisiseko kunxibelelwano olungenazingcingo.sihlala sisithi "ilahleko yothumelo yi-xx dB," "amandla othumelo yi-xx dBm," "inzuzo ye-eriyali yi-xx dBi" ...

Ngamanye amaxesha, le dB X inokubhideka kwaye ibangele iimpazamo zokubala.Ngoko ke, yintoni umahluko phakathi kwazo?

Umcimbi kufuneka uqale nge-dB.

Xa kufikwa kwi-dB, eyona ngcamango ixhaphakileyo yi-3dB!

I-3dB ibonakala rhoqo kwidayagram yamandla okanye i-BER (i-Bit Error Rate).Kodwa, enyanisweni, akukho mfihlelo.

Ukuhla kwe-3dB kuthetha ukuba amandla ancitshiswa ngesiqingatha, kwaye inqaku le-3dB lithetha i-half-power point.

I-+3dB ithetha amandla aphindwe kabini, -3Db ithetha ukuhla ngu-½.Ivela njani le nto?

Ngokwenene ilula kakhulu.Makhe sijonge kwifomula yokubala ye-dB:

I-dB imele ubudlelwane phakathi kwamandla e-P1 kunye negunya lokubhekisela kwi-P0.Ukuba i-P1 iphindwe kabini ngu-P0, ngoko:

ukuba i-P1 sisiqingatha sika-P0, ngoko,

malunga neekhonsepthi ezisisiseko kunye nepropathi yokusebenza kweelogarithms, unokuphonononga iimathematika zelogarithms.

[Umbuzo]: Amandla anyuswe ngamaxesha ka-10.Zingaphi idB apho?

Nceda ukhumbule ifomula apha.

+3 *2

+10*10

-3 / 2

-10 / 10

+3dB ithetha ukuba amandla anyuswe ngamaxesha ama-2;

+10dB kuthetha ukuba amandla anyuswe ngamaxesha ali-10.

-3 dB ithetha ukuba amandla ancitshiswe abe yi-1/2;

-10dB ithetha ukuba amandla ancitshiswe ukuya kwi-1/10.

Ingabonwa ukuba i-dB lixabiso elihambelanayo, kwaye injongo yayo kukuvakalisa inani elikhulu okanye elincinci kwifom emfutshane.

Le fomula inokuququzelela kakhulu ukubala kwethu kunye nenkcazo.Ngokukodwa xa uzoba ifom, ungayigcwalisa ngengqondo yakho.

Ukuba uyayiqonda i-dB, ngoku, masithethe ngamanani osapho lwe-dB:

Masiqale ngeyona dBm isetyenziswa kakhulu kunye nedBw.

I-dBm kunye ne-dBw ziza kuthatha indawo yereferensi yamandla e-P0 kwifomula ye-dB nge-1 mW, 1W.

I-1mw kunye ne-1w ngamaxabiso aqinisekileyo, ngoko i-dBm kunye ne-dBw zinokubonisa ixabiso elipheleleyo lamandla.

Okulandelayo yitafile yoguqulo lwamandla kwireferensi yakho.

Kufuneka sikhumbule:

1w = 30dBm

30 luphawu, olulingana no-1w.

Khumbula oku, kwaye udibanise yangaphambili "+3 *2, +10*10, -3/2, -10/10" unokwenza izibalo ezininzi:

[Umbuzo] 44dBm = ?w

Apha, kufuneka siqaphele ukuba:

Ngaphandle kwe-30dBm kwicala lasekunene leequation, ezinye izinto eziseleyo mazibonakaliswe kwi-dB.

[Umzekelo] Ukuba amandla emveliso ka-A ngama-46dBm kwaye amandla aphumayo ka-B ngama-40dBm, kunokutshiwo ukuba u-A ngu-6dB mkhulu kuno-B.

[Umzekelo] Ukuba i-eriyali A yi-12 dBd, i-eriyali B yi-14dBd, kunokuthiwa uA yi-2dB encinci kuno-B.

Umzekelo, i-46dB ithetha ukuba i-P1 ngama-40 amawaka amaxesha ngo-P0, kwaye i-46dBm ithetha ukuba ixabiso le-P1 ngu-40w.Mnye kuphela umahluko we-M, kodwa intsingiselo inokwahluka ngokupheleleyo.

Usapho lwe-dB oluqhelekileyo lukwanalo ne-dBi, i-dBd, kunye ne-dBc.Indlela yabo yokubala iyafana nendlela yokubala ye-dB, kwaye imele ixabiso elihambelanayo lamandla.

Umahluko kukuba imigangatho yabo yereferensi yahlukile.Oko kukuthi, intsingiselo yereferensi yamandla P0 kwidinomineyitha yahlukile.

Ngokuqhelekileyo, ukuvakalisa inzuzo efanayo, echazwe kwi-dBi, yi-2.15 enkulu kunokuba ichazwe kwi-dBd.Lo mahluko ubangelwe zizikhokelo ezahlukeneyo zee-eriyali ezimbini.

Ukongeza, usapho lwe-dB alunakumela kuphela inzuzo kunye nokulahleka kwamandla kodwa ikwamele i-voltage, yangoku, kunye neaudio, njl.

Kufuneka kuqatshelwe ukuba ukufumana amandla, sisebenzisa i-10lg (Po / Pi), kunye ne-voltage kunye ne-current, sisebenzisa i-20lg (Vo / Vi) kunye ne-20lg (Lo / Li)

Ivela njani lento ka2 ngaphezulu?

La maxesha e-2 athathwe kwisikwere sefomula yokuguqula amandla ombane.I-n-amandla kwilogarithm ihambelana namaxesha ka-n emva kokubala.

Unokuphonononga ikhosi yakho yefiziksi yesikolo samabanga aphakamileyo malunga nobudlelwane boguqulo phakathi kwamandla, amandla ombane, kunye nangoku.

Ekugqibeleni, ndiye ndathobela amanye amalungu osapho olukhulu lwe-dB kwireferensi yakho.

Ixabiso elizalanayo:

Ixabiso eligqibeleleyo:

Kwaye, makhe sijonge ukuba uyaqonda okanye hayi.

[Umbuzo] 1. Amandla e-30dBm yi

[Umbuzo] 2. Kucingelwa ukuba inani elipheleleyo lemveliso yeseli yi-46dBm, xa kukho ii-eriyali ezi-2, amandla e-eriyali enye