Chiyambi cha kugwiritsa ntchito RF optical transmission RF pa CHIKWANGWANI

Chiyambi cha kugwiritsa ntchitoKutumiza kwa RF kuwalaRF pamwamba pa Ulusi

M'zaka zaposachedwa, kulumikizana kwa ma microwave ndi ukadaulo wolumikizirana ndi ma optical telecommunications kwakula mofulumira. Maukadaulo onsewa apita patsogolo kwambiri m'magawo awo, komanso apangitsa kuti ntchito zolumikizirana pafoni ndi kutumiza deta zipite patsogolo kwambiri, zomwe zapangitsa kuti miyoyo ya anthu ikhale yosavuta. Maukadaulo awiriwa a kulumikizana kwa ma microwave ndi kulumikizana kwa ma photoelectric ali ndi zabwino zake, komanso ali ndi zovuta zina zomwe sizingathetsedwe. Kutumiza kwa ma photoelectric kumafuna kulumikizana kwa thupi, ndipo pali zofooka zina pakusinthasintha, kulumikizana mwachangu komanso kuyenda kwa zomangamanga. Kulumikizana kwa ma microwave kuli ndi zofooka zina pakutumiza kwakutali komanso mphamvu yayikulu, ndipo ma microwave amafunika kukulitsidwa pafupipafupi ndikutumizanso, ndipo bandwidth yotumizira imachepetsedwa ndi ma carrier frequency. Izi zidapangitsa kuti microwave ndi optical Fiber transmission technology ziphatikizidwe, kutanthauza, Radio over Fiber (ROF), yomwe nthawi zambiri imatchedwa.RF pamwamba pa Ulusi, kapena ukadaulo wakutali wa ma radio frequency. Gawo lomwe limagwiritsidwa ntchito kwambiri mu ukadaulo wa RF over Fiber ndi gawo la kulumikizana kwa fiber optical, kuphatikiza malo osungira mafoni, makina ogawa, intaneti yopanda zingwe, TV ya chingwe, kulumikizana kwa netiweki yachinsinsi ndi zina zotero. M'zaka zaposachedwa, chifukwa cha kukwera kwa ma microwave photonics, ukadaulo wa RF over Fiber wakhala ukugwiritsidwa ntchito kwambiri mu microwave photon radar, kulumikizana kwa UAV, kafukufuku wa zakuthambo ndi magawo ena. Malinga ndi mitundu yosiyanasiyana ya laser modulation, kulumikizana kwa laser kumatha kugawidwa m'magawo amkati ndi akunja, komwe kumagwiritsidwa ntchito kwambiri ndi external modulation, ndipo RF over Fiber kutengera external laser modulation ikufotokozedwa mu pepalali. Maulalo a RF over Fiber amapangidwa makamaka ndi transceiver ya optical, transmission, ndiMaulalo a ROF, monga momwe zasonyezedwera pachithunzi chotsatirachi:

Chidule cha gawo la kuwala. LD imagwiritsidwa ntchito kwambiriMa laser a DFB(mtundu wa mayankho ogawidwa), omwe amagwiritsidwa ntchito pa phokoso lochepa, mapulogalamu amphamvu kwambiri, ndipo ma laser a FP (mtundu wa Fabry-Perot) amagwiritsidwa ntchito pa mapulogalamu osavuta kugwiritsa ntchito. Ma wavelength omwe amagwiritsidwa ntchito kwambiri ndi 1064nm ndi 1550nm. PD ndichowunikira zithunzi, ndipo kumapeto ena a ulalo wa fiber optic, kuwalako kumazindikirika ndi PIN photodiode ya wolandila, yomwe imasintha kuwalako kukhala chizindikiro chamagetsi kenako n’kupita ku sitepe yodziwika bwino yogwiritsira ntchito magetsi. Ulusi wowala womwe umagwiritsidwa ntchito polumikizira pakati nthawi zambiri umakhala ulusi wowala wa single-mode ndi multi-mode. Ulusi wowala wa single-mode umagwiritsidwa ntchito kwambiri mu netiweki ya msana chifukwa cha kufalikira kwake kochepa komanso kutayika kochepa. Ulusi wowala wa multimode umagwiritsidwa ntchito pa netiweki yapafupi chifukwa ndi wotsika mtengo kupanga ndipo ukhoza kulandira ma transmissions angapo nthawi imodzi. Kuchepa kwa chizindikiro cha kuwala mu ulusi ndi kochepa kwambiri, kokha ~0.25dB/km pa 1550nm.

Kutengera ndi mawonekedwe a ma transmission a linear ndi ma transmission a kuwala, ma ROF link ali ndi ubwino wotsatirawu:

• Kutayika kochepa kwambiri, kuchepa kwa ulusi wochepera 0.4 dB/km

• Kutumiza kwa fiber ultra-bandwidth, kutayika kwa fiber popanda kutengera kuchuluka kwa ma frequency

• Kulumikizana ndi mphamvu yonyamula ma siginolo/bandwidth yokwera mpaka 110GHz • Kukana kwa Electromagnetic Interference (EMI) (nyengo yoipa siikhudza ma siginolo)

• Mtengo wotsika pa mita imodzi • Ulusi ndi wofewa komanso wosinthasintha, wolemera pafupifupi 1/25 ya waveguide ndi 1/10 ya chingwe cha coaxial.

• Kakonzedwe kosavuta komanso kosinthasintha ka ma modulators a electro-optic (a machitidwe ojambulira azachipatala ndi makina)