Indlela yokuchaza nokubala i-dB, i-dBm, i-dBw…muphi umehluko phakathi kwakho?

Indlela yokuchaza nokubala i-dB, i-dBm, i-dBw…muphi umehluko phakathi kwakho?

I-dB kufanele kube umqondo oyisisekelo kakhulu ekuxhumaneni okungenantambo.sivamise ukuthi "ukulahleka kokudlulisela yi-xx dB," "amandla okudlulisela yi-xx dBm," "inzuzo ye-antenna yi-xx dBi" ...

Ngezinye izikhathi, le dB X ingase idideke futhi ibangele amaphutha okubala.Ngakho, uyini umehluko phakathi kwabo?

Indaba kufanele iqale nge-dB.

Uma kukhulunywa nge-dB, umqondo ovame kakhulu yi-3dB!

I-3dB ivamise ukuvela kumdwebo wamandla noma i-BER (I-Bit Error Rate).Kodwa, eqinisweni, ayikho imfihlakalo.

Ukwehla kwe-3dB kusho ukuthi amandla ehliswa ngesigamu, kanti iphoyinti le-3dB lisho iphuzu lamandla ayingxenye.

I-+3dB isho amandla aphindwe kabili, -3Db isho ukuthi ukuncipha ngu-½.Lokhu kwavela kanjani?

Empeleni ilula kakhulu.Ake sibheke ifomula yokubala ye-dB:

I-dB imele ubudlelwano phakathi kwamandla e-P1 namandla ereferensi u-P0.Uma i-P1 iphindwe kabili ku-P0, khona-ke:

uma i-P1 iyingxenye ka-P0, khona-ke,

mayelana nemiqondo eyisisekelo kanye nempahla yokusebenza yama-logarithms, ungabuyekeza izibalo zama-logarithms.

[Umbuzo]: Amandla akhuphuka izikhathi eziyi-10.Mangaki ama-dB lapho?

Sicela ukhumbule ifomula lapha.

+3 *2

+10*10

-3/2

-10/10

+3dB kusho ukuthi amandla anda izikhathi ezi-2;

I-+10dB isho ukuthi amandla akhuphuka izikhathi eziyi-10.

-3 dB kusho ukuthi amandla ehlisiwe abe yi-1/2;

-10dB kusho ukuthi amandla ehliselwe ku-1/10.

Kungabonakala ukuthi i-dB iyinani elihlobene, futhi umgomo wayo ukuveza inombolo enkulu noma encane ngendlela emfushane.

Le fomula ingenza kube lula ukubala kwethu nencazelo.Ikakhulukazi uma udweba ifomu, ungaligcwalisa ngobuchopho bakho.

Uma uqonda i-dB, manje, ake sikhulume ngezinombolo zomndeni we-dB:

Ake siqale nge-dBm ne-dBw esetshenziswa kakhulu.

I-dBm kanye ne-dBw kuzothatha indawo yamandla ayireferensi u-P0 kufomula ye-dB ngo-1 mW, 1W.

U-1mw no-1w kungamanani aqondile, ngakho i-dBm ne-dBw zingamelela inani eliphelele lamandla.

Okulandelayo yithebula lokuguqulwa kwamandla lereferensi yakho.

Kufanele sikhumbule:

1w = 30dBm

30 uphawu lokuma, elilingana no-1w.

Khumbula lokhu, futhi uhlanganise eyedlule "+3 *2, +10*10, -3/2, -10/10" ungenza izibalo eziningi:

[Umbuzo] 44dBm = ?w

Lapha, kufanele siqaphele ukuthi:

Ngaphandle kuka-30dBm ohlangothini lwesokudla lwesibalo, zonke ezinye izinto ezihlukene kufanele zivezwe nge-dB.

[Isibonelo] Uma amandla okukhiphayo ka-A engu-46dBm futhi amandla okukhiphayo ka-B engu-40dBm, kungashiwo ukuthi u-A ungu-6dB mkhulu kuno-B.

[Isibonelo] Uma uthi A luyi-12 dBd, uthi B luyi-14dBd, kungashiwo ukuthi u-A ungu-2dB mncane kuno-B.

Isibonelo, i-46dB isho ukuthi i-P1 iphindwe izikhathi eziyizinkulungwane ezingu-40 ngo-P0, futhi u-46dBm usho ukuthi inani lika-P1 lingu-40w.Munye kuphela umehluko we-M, kodwa incazelo ingahluka ngokuphelele.

Umndeni ojwayelekile we-dB nawo une-dBi, dBd, ne-dBc.Indlela yabo yokubala iyafana nendlela yokubala ye-dB, futhi imelela inani elihlobene lamandla.

Umehluko wukuthi izindinganiso zabo zokubhekisela zihlukile.Okusho ukuthi, incazelo yamandla okubhekisela e-P0 ku-denominator ihlukile.

Ngokuvamile, ukuveza inzuzo efanayo, evezwe ku-dBi, kukhulu ngo-2.15 kunokuvezwa ku-dBd.Lo mehluko udalwa iziqondiso ezihlukene zezinti ezimbili.

Ngaphezu kwalokho, umndeni we-dB awukwazi ukumela inzuzo nokulahlekelwa amandla kuphela kodwa futhi umele i-voltage, yamanje, nomsindo, njll.,

Kufanele kuqashelwe ukuthi ukuze sizuze amandla, sisebenzisa u-10lg(Po/Pi), futhi ku-voltage kanye namanje, sisebenzisa u-20lg(Vo/Vi) no-20lg(Lo/Li)

Lokhu kwavela kanjani izikhathi ezi-2 ngaphezulu?

Lezi zikhathi ezi-2 zithathwe kusikwele sefomula yokuguqula amandla kagesi.I-n-amandla ku-logarithm ihambisana nezikhathi ezingu-n ngemva kokubala.

Ungabuyekeza izifundo zakho ze-physics zesikole samabanga aphezulu mayelana nobudlelwano bokuguqulwa phakathi kwamandla, i-voltage, kanye nesimanje.

Ekugcineni, ngithobele amanye amalungu omndeni omkhulu we-dB ngereferensi yakho.

Inani elihlobene:

Inani eliphelele:

Futhi, ake sihlole ukuthi uyaqonda noma cha.

[Umbuzo] 1. Amandla we-30dBm yi

[Umbuzo] 2. Ngokucabangela ukuthi inani eliphelele lokukhishwa kweseli lingu-46dBm, uma kukhona izimpondo ezi-2, amandla othi olulodwa