Mokhoa oa ho hlalosa le ho bala dB, dBm, dBw… phapang ke efe lipakeng tsa tsona?
dB e lokela ho ba mohopolo oa mantlha oa puisano ka waelese.hangata re re "tahlehelo ea phetisetso ke xx dB," "matla a phetiso ke xx dBm," "antenna e fumanehe ke xx dBi" ...
Ka linako tse ling, dB X ena e ka ferekanngoa mme ea baka liphoso tsa lipalo.Joale, phapang ke efe pakeng tsa bona?
Taba e tlameha ho qala ka dB.
Ha ho tluoa ho dB, mohopolo o tloaelehileng haholo ke 3dB!
Hangata 3dB e hlaha setšoantšong sa matla kapa BER (Bit Error Rate).Empa, ha e le hantle, ha ho na sephiri.
Ho theoha ha 3dB ho bolela hore matla a fokotsehile ka halofo, 'me ntlha ea 3dB e bolela ntlha ea halofo ea matla.
+3dB e bolela matla a habeli, -3Db e bolela hore phokotso ke ½.See se hlahile joang?
Ha e le hantle e bonolo haholo.Ha re shebeng mokhoa oa ho bala oa dB:
dB e emela kamano lipakeng tsa matla P1 le matla a referense P0.Haeba P1 e habeli P0, joale:
haeba P1 ke halofo ea P0, joale,
mabapi le mehopolo ea mantlha le thepa ea ts'ebetso ea logarithms, o ka hlahloba lipalo tsa logarithms.
[Potso]: Matla a eketsoa ka nako ea 10.Ke dB e kae moo?
Ka kopo hopola foromo mona.
+3 *2
+10*10
-3 / 2
-10 / 10
+ 3dB e bolela hore matla a eketseha ka makhetlo a 2;
+10dB e bolela hore matla a eketseha ka makhetlo a 10.
-3 dB e bolela hore matla a fokotsehile ho 1/2;
-10dB e bolela hore matla a fokotsehile ho 1/10.
Ho ka bonoa hore dB ke boleng bo lekanyelitsoeng, mme sepheo sa eona ke ho hlahisa palo e kholo kapa e nyane ka mokhoa o khuts'oane.
Foromo ena e ka re thusa haholo lipalo le tlhaloso.Haholo-holo ha u taka foromo, u ka e tlatsa ka boko ba hau.
Haeba u utloisisa dB, joale, ha re bue ka linomoro tsa malapa a dB:
Ha re qaleng ka dBm le dBw tse sebelisoang haholo.
dBm le dBw li lokela ho nkela matla a referense P0 ka foromo ea dB ka 1 mW, 1W.
1mw le 1w ke litekanyetso tse hlakileng, kahoo dBm le dBw li ka emela boleng bo felletseng ba matla.
Latelang ke tafole ea ho fetola matla bakeng sa referense ea hau.
| Watt | dBm | dBw |
| 0.1 pW | -100 dBm | -130 dBw |
| 1 pw | -90 dBm | -120 dBw |
| 10 pw | -80 dBm | -110 dBw |
| 100 pW | -70 dBm | -100 dBw |
| 1n W | -60 dBm | -90 dBw |
| 10 nW | -50 dBm | -80 dBw |
| 100 nW | -40 dBm | -70 dBw |
| 1 uW | -30 dBm | -60 dBw |
| 10 uW | -20 dBm | -50 dBw |
| 100 uW | -10 dBm | -40 dBw |
| 794 uW | -1 dBm | -31 dBw |
| 1.000 mW | 0dBm | -30 dBw |
| 1.259 Mw | 1dBm | -29 dBw |
| 10 mW | 10dBm | -20 dBw |
| 100 Mw | 20dBm | -10 dBw |
| 1 W | 30dBm | 0dbw |
| 10 W | 40dBm | 10dbw |
| 100 W | 50dBm | 20dbw |
| 1 kW | 60dBm | 30dbw |
| 10 kW | 70dBm | 40dbw |
| 100 kW | 80dBm | 50dbw |
| 1 MW | 90dBm | 60dbw |
| 10 MW | 100 dBm | 70dbw |
Re lokela ho hopola:
1w = 30dBm
30 ke palo, e lekanang le 1w.
Hopola sena, 'me u kopanye tse fetileng "+3 *2, +10*10, -3/2, -10/10" u ka etsa lipalo tse ngata:
[Potso] 44dBm =?w
Mona, re lokela ho hlokomela hore:
Ntle le 30dBm ka lehlakoreng le letona la equation, likarolo tse ling kaofela li tlameha ho hlahisoa ka dB.
[Mohlala] Haeba matla a tlhahiso ea A e le 46dBm mme matla a tlhahiso ea B ke 40dBm, ho ka boleloa hore A ke 6dB e kholo ho feta B.
[Mohlala] Haeba lenakana A le 12 dBd, lenakana B le 14dBd, ho ka boleloa hore A ke 2dB e nyane ho feta B.
Mohlala, 46dB e bolela hore P1 ke makhetlo a likete tse 40 P0, 'me 46dBm e bolela hore boleng ba P1 ke 40w.Ho na le phapang e le 'ngoe feela ea M, empa moelelo o ka fapana ka ho feletseng.
Lelapa le tloaelehileng la dB le boetse le na le dBi, dBd, le dBc.Mokhoa oa bona oa ho bala o tšoana le mokhoa oa ho bala oa dB, 'me o emela boleng bo lekanyelitsoeng ba matla.
Phapang ke hore litekanyetso tsa bona tsa litšupiso li fapane.Ke hore, moelelo oa matla a referense P0 ho denominator o fapane.
Ka kakaretso, ho hlahisa phaello e tšoanang, e hlalositsoeng ho dBi, ke 2.15 e kholo ho feta e hlalositsoeng ho dBd.Phapang ena e bakoa ke litaelo tse fapaneng tsa li-antenna tse peli.
Ntle le moo, lelapa la dB le ke ke la emela phaello le tahlehelo ea matla feela empa hape le emela voltage, hajoale, le molumo, jj.
Hoa lokela ho hlokomeloa hore bakeng sa ho fumana matla, re sebelisa 10lg (Po / Pi), 'me bakeng sa motlakase le hona joale, re sebelisa 20lg (Vo / Vi) le 20lg (Lo / Li)
Hona makhetlo a 2 ho feta a tsoa joang?
Nako ena ea 2 e tsoa ho sekwere sa foromo ea ho fetola matla a motlakase.N-matla a ho logarithm a lumellana le linako tsa n ka mor'a palo.
U ka lekola thuto ea hau ea fisiks ea sekolo se phahameng mabapi le kamano ea phetoho lipakeng tsa matla, motlakase le hona joale.
Qetellong, ke ile ka latela litho tse ling tse kholo tsa lelapa la dB bakeng sa tšupiso ea hau.
Boleng bo amanang:
| Letšoao | Mabitso a felletseng |
| dB | decibel |
| dBc | sesebelisoa sa decibel |
| dBd | decibel dipole |
| dBi | decibel-isotropic |
| li-dBFs | decibel tekanyo e feletseng |
| dBrn | lerata la decibel |
Boleng bo felletseng:
| Letšoao | Mabitso a felletseng | Reference Standard |
| dBm | decibel milliwatt | 1mW |
| dBW | decibel watt | 1W |
| dBμV | decibel microvolt | 1μVRMS |
| dBmV | decibel millivolt | 1mVRMS |
| dBV | li-volt tsa decibel | 1VRMS |
| dBu | decibel e laotsoeng | 0.775VRMS |
| dBμA | decibel microampere | 1μA |
| dBmA | decibel milliampere | 1mA |
| dBohm | decibel ohms | 1Ω |
| dBHz | decibel hertz | 1Hz |
| dBSPL | boemo ba khatello ea molumo oa decibel | 20μPa |
'Me, ha re hlahlobeng hore na ua utloisisa kapa che.
[Potso] 1. Matla a 30dBm ke
[Potso] 2. Ho nka hore kakaretso ea kakaretso ea sele ke 46dBm, ha ho na le li-antenna tse 2, matla a lenaka le le leng ke
Nako ea poso: Jun-17-2021