Kana wakashanda muindasitiri yekutepfenyura kweredhiyo kwenguva yakati, unofanira kunge wakaona zvikamu izvi zvakaiswa pamamwe mabhuku ezvimwe midziyo yekutepfenyura seFM antenna kana RF amplifier: dB, dBi, dBm. Vanotaridzika zvakafanana, asi unoziva zvavanoreva uye kuti ungazvisiyanisa sei? Mushure mekuverenga chinyorwa ichi, iwe uchaziva zvazvinoreva uye maitiro ekuzvisiyanisa.
gutsikana
Tsanangudzo Yekuwana
Tisati tasvika padanho, ngatipindure mibvunzo miviri: chii chinowanikwa ne FM nhepfenyuro antenna zvinorevei?
Zvichienderana neWikipedia, mune inotapurirana antenna, iyo inowanikwa inotsanangura kuti antenna inoshandura sei simba rekupinza kuita masaisai eredhiyo anotungamirwa munzira yakatarwa. Mune antenna inogashira, mubairo unotsanangura kuti antenna inoshandura sei masaisai eredhiyo achisvika kubva kune yakatemwa nzira kuita simba remagetsi. Kana pasina gwara rinotsanangurwa, bhenefiti inonzwisiswa inoreva kukosha kwepamusoro kwemubairo, kuwana kwakanangana neiyo huru lobe yeantenna.
Muchidimbu, antenna yeFM haigone kuvandudza simba remudziyo wekutepfenyura kana mudziyo unogashira pachawo, asi antenna inogona kutarisisa aya emagetsi kana masaisai eredhiyo munzira yakatarwa. Nenzira iyi, iyo radio wave intensity inoburitswa neantenna munzira ino ichave yakasimba kupfuura yekutanga, izvo zvinoreva zvakare kuti kusimba kweredhiyo kune mamwe mativi kuchave kushoma pane yekutanga. Saka bhenefiti ireshiyo yeredhiyo wave intensity munzira ine simba remwaranzi ine simba kune yekutanga radio wave intensity.
Yakasiyana Kuwana kweIsotropic Antenna uye Yakakwira Gain Antenna
Tsanangudzo uye Kusiyana kwe dB, dBi uye dBm
Mushure mekuva nekunzwisisa kwekutanga kweiyo pfungwa yekuwana, zviri nyore kunzwisisa zvikamu zvitatu zvedB, dBi, uye dBm.
Tsanangudzo yedB
Takadzidza kuchikoro kuti dB inomiririra ruzha rweruzha. Nekudaro, zvakasiyana mumunda weRF. Chimiro chayo dB = 10log (x/y) (apo x uye Y inomiririra kusimba kwemwaranzi yemaantenna maviri) uye inomiririra mutsauko uripo pakati pemazinga emagetsi emaantenna maviri (kuwana kana kurasikirwa)
Kuburikidza nekuverenga, tinogona kuziva kuti kana x asina simba pane y, dB haina kunaka; Kana x na y vakaenzana, dB inoenzana na0; Kana x = 2y, dB yakaenzana na 3. Zvimwechetezvo, 6dB zvinoreva x akaenzana ne4 nguva y uye 12dB zvinoreva x akaenzana ne16 nguva y. Izvo zvinofanirwa kucherechedzwa kuti kana iwe uchida kuyera iyo chaiyo kuwana kana chaiyo simba musiyano weiyo wired antenna, ndapota funga kurasikirwa kweRF tambo pachayo.
Tsanangudzo yedBi
Kana iwe uchida kuenzanisa kusimba kwemwaranzi yekuwana inotungamira antenna uye omnidirectional antenna, iwe unofanirwa kutora dBi sechikamu, apo "i" inomiririra isotopic, uye iyo yekuverenga formula yedBi yakafanana neiyo yedBi.
Nekuti iyo omnidirectional antenna ichapenya redhiyo siginecha ne "sphere" yakakwana, ndiko kuti, ine kusimba kwakafanana kweredhiyo munzira imwe neimwe. Kana iyo antenna ikawana mune yakatsanangurwa gwara, lobe yayo inotetepa, ndiko kuti, iyo FM radio chiteshi antenna inotora imwe kona seyakanyanya nzira yemwaranzi, uye kusimba kwemwaranzi kwakasimba kupfuura kusimba kwemwaranzi yekutanga. Huyero hwekusimba kwemwaranzi yeiyi main radiation angle kune yekutanga radiation intensity ndiko kuwana kweino kutungamira antenna. Naizvozvo, kana dBi yakakura kupfuura 0, inoratidza kuti antenna ine directivity.
Iyo Radiation Pateni yeIsotropic Antenna
Tsanangudzo yedBm
Kunyangwe dBm ichiita senge dBi, haimiriri kusimba kwemwaranzi. Iyo "m" mu dBm inomiririra milliwatts (MW), iyo yakafanana nedBi, iriwo kukosha kwayo, asi inomiririra kukosha kwesimba rekutapurirana ne1MW sekukosha kwereferensi. Chimiro chacho ndeichi: dBm = 10 log (P1/1MW)
Kunyangwe dBm iri kukosha kwayo, inogona kushandurwa kuita iro chairo simba remidziyo mushure mekushandurwa kweyuniti. Semuenzaniso, 0dbm = 1MW, 1dbm = 1.3MW, 10dBm = 1W, 60dbm = 1000W ... Inogona kuonekwa kuti inogona kushandisa maitiro akareruka kumiririra simba duku zvikuru kana simba guru. Naizvozvo, iro chairo simba rezvishandiso zvakasiyana richaratidzwa mudBm.
| Watt kune dBm Shanduko Tafura |
| Simba (watt) |
Simba (dBm) |
| 0.00001 W |
-20 dBm |
| 0.0001 W |
-10 d Bm |
| 0.001 W |
0dBm |
| 0.01 W |
10dBm |
| 0.1 W |
20dBm |
| 1 W |
30dBm |
| 10 W |
40dBm |
| 100 W |
50dBm |
| 1000 W |
60dBm |
Iwo Musiyano pakati pe dB, dBi uye dBm
Muchidimbu, dB, dBm, uye dBm ese ane hukama, asi ane maviri anotevera akasiyana:
- Iyo dB nedBi inoshandiswa kumiririra kusimba kwehukama (kuwana kana kurasikirwa) kweredhiyo radiation yeantenna, nepo dBm ichishandiswa kumiririra iro chairo simba remudziyo.
- Iyo dB kukosha kwehukama hweiyo radiation intensity musiyano pakati pemaantenna maviri, uye dBi ndiyo redhiyo chiratidzo chesimba rekuenzanisa yeantenna isati yasvika uye mushure mekuwana (kana kutaridzika).
Mibvunzo Inonyanya Kubvunzwa
1. Q: Chii chinonzi dB Kuwana kweFM Broadcast Antenna?
A: Iko kugona kupenya zvakanyanya kana zvishoma munzira yeFM Broadcast Antennas.
Iyo dB inoyerwa nereshiyo yesimba, ikozvino kana voltage yezviratidzo zviviri. Iyo ndiyo inonyanya kushandiswa unit kuti uwane.
2. Mubvunzo: Nei Simba reSigironi richiyerwa nedB?
A: Nekuti simba rechiratidzo rinosiyana logarithmically asi kwete mutsetse.
Isu tinoshandisa dB kuyera simba rechiratidzo nekuti simba rechiratidzo rinosiyana logarithmically, kwete mutsara. Chikero chelogarithmic chinobvumira nhamba dzakareruka kumiririra shanduko huru mumatanho echiratidzo.
3. Q: Ko -3 dB Gain Inorevei kune Antenna?
A: -3dB kuwana inoreva kuti iyo inobuda inowanikwa yakaderedzwa kusvika 70.71% yehupamhi hwayo.
Iyo -3dB kuwana poindi inotsanangura iyo yekubuda nhanho yakaderedzwa kusvika 70.71% yehupamhi hwayo. Kana isu tinogona kutaura kuti iyo -3dB poindi zvakare iyo frequency iyo iyo inowanikwa yehurongwa yakaderedzwa kusvika 0.707 yehukuru hwayo.
4. Q: Yakakwirira dBi Iri Nani pane Iyo Yakaderera?
A: Kwete, mari yese ine mativi maviri. Yepamusoro dBi inoreva kupenya mberi asi kudiki.
Iyo yakakwira iyo dBi nhamba yeantenna, iyo yakakwira purofiti yainayo, asi shoma yeyakafara munda pateni. Zvinoreva kuti simba rechiratidzo richaenda mberi asi munzira yakamanikana. Kana iwe uchida kupenya nzira yakafara, unofanirwa kuwedzera mamwe antenna.
mhedziso
Isu tinodzidza tsananguro uye mutsauko wedB, dBi, uye dBm kuburikidza nezviri pamusoro. Zvinonyanya kubatsira kuti iwe uzive iyo antenna theory zviri nani usati wapinda muRF ndima. Kana uchida kuziva zvakawanda pamusoro pekutepfenyura, kana kuti uchida chero midziyo yekutepfenyura yeredhiyo inotengeswa, ndapota sununguka bata timu yedu yeRF nyanzvi, iwe uchapindurwa nekukurumidza sezvinobvira. Uye usakanganwa kugovera iyi blog kana ichikubatsira iwe!
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