Nzira yekutsanangura uye kuverenga sei dB, dBm, dBw ... ndeupi musiyano uripo pakati pazvo?

Nzira yekutsanangura uye kuverenga sei dB, dBm, dBw ... ndeupi musiyano uripo pakati pazvo?

dB inofanirwa kunge iri iyo yakanyanya kukosha pfungwa mukutaurirana isina waya.tinowanzo kuti "kutapurira kurasikirwa ndeye xx dB," "simba rekutapurirana iri xx dBm," "antenna kuwana ndeye xx dBi" ...

Dzimwe nguva, iyi dB X inogona kuvhiringika uye kutokonzera zvikanganiso zvekuverenga.Saka, ndeupi musiyano pakati pavo?

Nyaya yacho inofanira kutanga nedB.

Kana zvasvika kune dB, pfungwa yakajairika ndeye 3dB!

3dB inowanzoonekwa mudhayagiramu yemagetsi kana BER (Bit Error Rate).Asi, chaizvoizvo, hapana chakavanzika.

Kudonha kwe3dB kunoreva kuti simba rakaderedzwa nehafu, uye 3dB poindi inoreva hafu-simba poindi.

+3dB zvinoreva simba rakapetwa kaviri, -3Db zvinoreva kudzikira i½.Izvi zvakabva sei?

Zviri chaizvo nyore.Ngatitarisei iyo yekuverenga formula ye dB:

dB inomiririra hukama pakati pesimba P1 uye rereferensi simba P0.Kana P1 iri kaviri P0, saka:

kana P1 iri hafu yeP0, saka,

nezve ekutanga pfungwa uye mashandiro ezvivakwa zvelogarithms, unogona kuongorora masvomhu elogarithms.

[Mubvunzo]: Simba rinowedzerwa negumi nguva.Ingani dB ipapo?

Ndapota rangarira fomula pano.

+3 *2

+10*10

-3 / 2

-10 / 10

+3dB zvinoreva kuti simba rinowedzerwa nekaviri;

+10dB zvinoreva kuti simba rinowedzerwa nekagumi.

-3 dB zvinoreva kuti simba rakaderedzwa kusvika 1/2;

-10dB zvinoreva kuti simba rakaderedzwa kusvika 1/10.

Zvinogona kuonekwa kuti dB inokosha, uye chinangwa chayo ndechekuratidza nhamba huru kana duku muchidimbu.

Iyi fomula inogona kufambisa zvakanyanya kuverenga kwedu uye tsananguro.Kunyanya pakudhirowa fomu, unogona kurizadza nehuropi hwako.

Kana iwe uchinzwisisa dB, ikozvino, ngatitaure nezve nhamba dzemhuri dzedB:

Ngatitangei neinonyanya kushandiswa dBm uye dBw.

dBm uye dBw ndezvekutsiva simba rereferenzi P0 mu dB formula ne 1 mW, 1W.

1mw uye 1w ndiwo makoshero chaiwo, saka dBm nedBw zvinogona kumiririra kukosha kwesimba.

Inotevera ndiyo tafura yekushandura simba rereferensi yako.

Tinofanira kuyeuka:

1w = 30dBm

30 ndiyo bhenji, iyo yakaenzana ne1w.

Rangarira izvi, uye sanganisa yapfuura "+3 *2, +10*10, -3/2, -10/10" unogona kuita akawanda masvomhu:

[Mubvunzo] 44dBm = ?w

Pano, tinofanira kuziva kuti:

Kunze kwe30dBm kudivi rekurudyi reequation, zvimwe zvinhu zvakapatsanurwa zvinofanira kuratidzwa mudB.

[Muenzaniso] Kana simba reA rinobuda riri 46dBm uye simba rekubuda reB iri 40dBm, zvinogona kunzi A i6dB yakakura kupfuura B.

[Muenzaniso] Kana antenna A iri 12 dBd, iyo antenna B iri 14dBd, zvinogona kunzi A idiki 2dB pane B.

Semuenzaniso, 46dB zvinoreva kuti P1 imakumi mana ezviuru zveP0, uye 46dBm zvinoreva kuti kukosha kweP1 i40w.Pane musiyano weM mumwe chete, asi zvinoreva zvinogona kunge zvakasiyana zvachose.

Mhuri yedB yakajairika zvakare ine dBi, dBd, uye dBc.Nzira yavo yekuverenga yakafanana neye dB yekuverenga nzira, uye inomiririra kukosha kwesimba.

Musiyano ndewekuti mareferensi maitiro akasiyana.Ndiko kuti, chirevo chereferensi simba P0 pane dhinominata zvakasiyana.

Kazhinji, kuratidza pfuma imwe chete, inoratidzwa mudBi, yakakura 2.15 pane inoratidzwa mudBd.Musiyano uyu unokonzerwa nemaitiro akasiyana eaya maviri antenna.

Pamusoro pezvo, iyo mhuri yedB haingomiriri kuwana uye kurasikirwa kwesimba chete asi zvakare inomiririra voltage, yazvino, uye odhiyo, nezvimwe.

Zvinofanira kucherechedzwa kuti kuti tiwane simba, tinoshandisa 10lg (Po/Pi), uye nokuda kwemhepo uye ikozvino, tinoshandisa 20lg (Vo/Vi) uye 20lg (Lo/Li)

Ko izvi zvakapetwa ka2 zvabva sei?

Iyi 2 nguva inotorwa kubva kune square yemagetsi emagetsi ekushandura formula.Iyo n-simba riri mulogarithm rinoenderana nen nguva mushure mekuverenga.

Iwe unogona kudzokorora kosi yako yechikoro chepamusoro chefizikisi nezve hukama hwekushandura pakati pesimba, voltage, uye zvazvino.

Pakupedzisira, ndakateerera dzimwe nhengo dzemhuri huru dzedB kune yako referensi.

Hukoshi hunoenderana

Mhedziso kukosha:

Uye, ngatitarisei kuti unonzwisisa here kana kuti kwete.

[Mubvunzo] 1. Simba re30dBm ndiro

[Mubvunzo] 2. Tichifunga kuti huwandu hwesero hunobuda hwesero i46dBm, kana paine 2 antennas, simba reimwe antenna