Uma usebenze embonini yokusakaza emsakazweni isikhathi esithile, kufanele ngabe usuwabonile lawa mayunithi amakwe kwamanye amamanyuwali wemishini ethile yokusakaza yomsakazo njenge-FM antenna noma i-RF amplifier: dB, dBi, dBm. Zibukeka zifana, kodwa uyazi ukuthi zisho ukuthini nokuthi ungazihlukanisa kanjani? Ngemva kokufunda lesi sihloko, uzokwazi incazelo yabo nokuthi ungawahlukanisa kanjani.
Okuqukethwe
Incazelo Yenzuzo
Ngaphambi kokufika ephuzwini, ake siphendule imibuzo emibili: iyini inzuzo ye- I-antenna yokusakaza ye-FM kusho?
Ngokusekelwe ku-Wikipedia, ku-antenna yokudlulisa, inzuzo ichaza ukuthi i-antenna iwaguqula kahle kanjani amandla okufaka abe amaza omsakazo aqondiswe ohlangothini oluthile. Ku-antenna eyamukelayo, inzuzo ichaza ukuthi i-antenna iwaguqula kahle kanjani amaza omsakazo afika esuka endaweni ethile abe amandla kagesi. Uma kungekho siqondiso esishiwo, inzuzo iqondwa njengokubhekisela enanini eliphakeme lenzuzo, inzuzo eqonde endaweni eyinhloko ye-antenna.
Ngamafuphi, uthi lwe-FM alukwazi ukuthuthukisa amandla edivayisi yokudlulisa noma idivayisi eyamukelayo ngokwayo, kodwa uthi lungakwazi ukugxilisa lawa maza amandla noma omsakazo ohlangothini oluthile. Ngale ndlela, umfutho wegagasi lomsakazo okhishwa i-antenna kuleli cala lizoba namandla kunelokuqala, okusho futhi ukuthi umfutho wamaza omsakazo kwezinye izinkomba uzoba buthaka kunewokuqala. Ngakho-ke inzuzo isilinganiso sokushuba kwegagasi lomsakazo ngalapho kuya khona ngamandla emisebe anamandla kuya kumfutho wegagasi lomsakazo lokuqala.
Inzuzo Ehlukile Ye-Isotropic Antenna kanye Ne-High Gain Antenna
Incazelo kanye Nomehluko we dB, dBi kanye ne-dBm
Ngemva kokuba nokuqonda okuyisisekelo komqondo wokuzuza, kulula kakhulu ukuqonda amayunithi amathathu e-dB, dBi, kanye ne-dBm.
Incazelo ye-dB
Sifunde esikoleni ukuthi i-dB imele ukuzwakala komsindo. Nokho, kwehlukile emkhakheni we-RF. Ifomula yayo ithi dB=10log(x/y)(lapho u-x kanye no-Y bemelela ukushuba kwemisebe kwezimpondo ezimbili) futhi imelela umehluko phakathi kwamazinga wamandla ezinti ezimbili(inzuzo noma ukulahlekelwa)
Ngokubala, singakwazi ukwazi ukuthi uma u-x ebuthaka kuno-y, i-dB inegethivu; Uma u-x no-y belingana, i-dB ilingana no-0; Uma x = 2y, i-dB ilingana no-3. Ngokufanayo, u-6dB usho ukuthi u-x ulingana no-4 izikhathi y futhi 12dB usho ukuthi x ulingana no-16 izikhathi y. Kufanele kuqashelwe ukuthi uma ufuna ukukala inzuzo yangempela noma umehluko wangempela wamandla we-antenna enezintambo, sicela ucabangele ukulahleka kwentambo ye-RF ngokwayo.
Incazelo ye-dBi
Uma ufuna ukuqhathanisa ubukhulu bemisebe ye-antenna eqondisayo kanye ne-omnidirectional antenna, kufanele uthathe i-dBi njengeyunithi, lapho u-"i" umele isotopic, kanye nefomula yokubala ye-dBi ifana neye-dBi.
Ngoba i-antenna ye-omnidirectional izokhipha isignali yomsakazo "nge-sphere", okungukuthi, inomfutho ofanayo womsakazo ohlangothini ngalunye. Lapho i-antenna inenzuzo endaweni ethile, i-lobe yayo izoba mncane, okungukuthi, i-antenna yesiteshi somsakazo we-FM ithatha i-engeli ethile njengendlela eyinhloko yemisebe, futhi umfutho wemisebe unamandla ukwedlula ukuqina kwemisebe yasekuqaleni. Isilinganiso sobukhulu bemisebe yale engeli yemisebe eyinhloko kumfutho wangempela wemisebe yinzuzo yale antenna eqondisayo. Ngakho-ke, uma i-dBi inkulu kuno-0, ikhombisa ukuthi i-antenna inokuqondisa.
Iphethini Yemisebe Ye-Antenna Ye-Isotropic
Incazelo ye-dBm
Nakuba i-dBm ibukeka njenge-dBi, ayimeli amandla emisebe. I-"m" ku-dBm imele ama-milliwatts (MW), afana ne-dBi, futhi iyinani elihlobene, kodwa imele inani elihlobene lamandla okudlulisela no-1MW njengenani eliyireferensi. Ifomula ithi: dBm = 10 log (P1/1MW)
Nakuba i-dBm iyinani elihlobene, ingaguqulelwa amandla angempela emishini ngemva kokuguqulwa kweyunithi. Isibonelo, i-0dbm = 1MW, 1dbm = 1.3MW, 10dBm = 1W, 60dbm = 1000W... Kungabonakala ukuthi ingasebenzisa amanani alula kakhulu ukumela amandla amancane kakhulu noma amandla amakhulu kakhulu. Ngakho-ke, amandla wangempela wamadivayisi ahlukahlukene azovezwa nge-dBm.
| I-Watt kuya ku-dBm Conversion Table |
| Amandla (watt) |
Amandla (dBm) |
| 0.00001 W |
-20 dBm |
| 0.0001 W |
-10 d Bm |
| 0.001 W |
I-0 dBm |
| 0.01 W |
I-10 dBm |
| 0.1 W |
I-20 dBm |
| 1 W |
I-30 dBm |
| 10 W |
I-40 dBm |
| 100 W |
I-50 dBm |
| 1000 W |
I-60 dBm |
Umehluko phakathi kwe-dB, dBi kanye ne-dBm
Kafushane, i-dB, i-dBm, ne-dBm wonke amanani ahlobene, kodwa anomehluko o-2 olandelayo:
- I-dB ne-dBi zisetshenziselwa ukumelela amandla ahlobene (inzuzo noma ukulahlekelwa) kwemisebe yomsakazo wothi, kuyilapho i-dBm isetshenziselwa ukumela amandla angempela ezinto zokusebenza.
- I-dB iyinani elihlobene lomehluko wamandla emisebe phakathi kwezimpondo ezimbili, futhi i-dBi iyisiqhathaniso samandla esignali yomsakazo we-antenna ngaphambi nangemuva kwenzuzo (noma umumo).
imibuzo ejwayelekile ukubuzwa
1. Q: Iyini Inzuzo ye-dB Ye-Antenna Yokusakaza Ye-FM?
A: Kuyikhono lokukhanyisa kakhulu noma ngaphansi lapho uqonde khona kuma-FM Broadcast Antennas.
I-dB ikalwa ngenani lamandla, lamanje noma i-voltage yamasignali amabili. Iyunithi esetshenziswa kakhulu ukuze kuzuze.
2. Q: Kungani Amandla Esiginali Akalwa nge-dB?
A: Ngoba amandla esiginali ayahluka ngokwe-logarithm kodwa hhayi ngokomugqa.
Sisebenzisa i-dB ukukala amandla esiginali ngoba amandla esiginali ayahluka ngokwe-logarithmically, hhayi ngokomugqa. Isikali se-logarithmic sivumela izinombolo ezilula ukuthi zimele izinguquko ezinkulu kumazinga esignali.
3. Q: Isho ukuthini i--3 dB Gain ku-Antenna?
A: Ukuzuza -3dB kusho ukuthi inzuzo yokukhipha yehliselwe ku-70.71% wezinga layo eliphezulu.
Iphoyinti lokuzuza -3dB lichaza izinga lokuzuza lokukhiphayo lehliselwe ku-70.71% wezinga layo eliphezulu. Noma singasho ukuthi iphuzu -3dB liphinde libe imvamisa lapho ukuzuza kwesistimu kuye kwehliselwe ku-0.707 yenani layo eliphezulu.
4. Q: Ingabe I-dBi Ephakeme Ingcono kune-Lower One?
A: Akunjalo, yonke into yemali inezinhlangothi ezimbili. I-dBi ephezulu isho ukukhazimula ngokuqhubekayo kodwa kuncane.
Uma iphezulu inombolo ye-dBi ye-antenna, iyanda inzuzo enayo, kodwa ingaphansi kwephethini yenkundla ebanzi. Kusho ukuthi amandla esignali azoqhubekela phambili kodwa ngendlela ewumngcingo. Uma ufuna ukukhanyisa indawo ebanzi, udinga ukungeza izinti ezengeziwe.
Isiphetho
Sifunda izincazelo nomehluko we-dB, dBi, ne-dBm ngokuqukethwe okungenhla. Kuwusizo kakhulu kuwe ukwazi ithiyori ye-antenna kangcono ngaphambi kokungena emkhakheni we-RF. Uma ufuna ukwazi okwengeziwe mayelana nokusakaza, noma udinga noma iyiphi imishini yokusakaza yomsakazo ethengiswayo, sicela ukhululeke xhumana nethimba lethu lochwepheshe be-RF, uzophendulwa ngokushesha ngangokunokwenzeka. Futhi ungakhohlwa ukwabelana ngale bhulogi uma iwusizo kuwe!
Funda futhi
