Gabatarwa ga Tsarin RF akan Fiber

Gabatarwa ga Tsarin RF akan Fiber

RF akan zareyana ɗaya daga cikin mahimman aikace-aikacen microwave photonics kuma yana nuna fa'idodi marasa misaltuwa a fannoni masu ci gaba kamar radar microwave photonic, telephoto na rediyo na sararin samaniya, da sadarwa ta jiragen sama marasa matuƙi.

RF akan fiberHaɗin ROFgalibi ya ƙunshi na'urorin watsawa na gani, masu karɓar haske da kebul na gani. Kamar yadda aka nuna a Hoto na 1.

Masu watsawa na gani: Lasers masu ra'ayin rabawa (Laser DFB) ana amfani da su a aikace-aikacen ƙananan hayaniya da kuma aikace-aikacen kewayon masu ƙarfi, yayin da ake amfani da lasers na FP a aikace-aikace masu ƙarancin buƙatu. Waɗannan lasers suna da tsawon tsayi na 1310nm ko 1550nm.

Mai karɓar haske: A ɗayan ƙarshen hanyar haɗin fiber optical, ana gano hasken ta hanyar amfani da PIN photodiode na mai karɓar, wanda ke mayar da hasken zuwa wutar lantarki.

Kebul na gani: Sabanin zare masu yanayin multimode, ana amfani da zare masu yanayin guda ɗaya a cikin hanyoyin haɗin layi saboda ƙarancin watsawa da ƙarancin asara. A tsawon tsayin 1310nm, raguwar siginar gani a cikin zaren gani bai kai 0.4dB/km ba. A 1550nm, bai kai 0.25dB/km ba.

Haɗin ROF tsarin watsawa ne na layi. Dangane da halayen watsawa na layi da watsawa na gani, haɗin ROF yana da fa'idodi masu zuwa na fasaha:

• Rage asara sosai, tare da raguwar zare ƙasa da 0.4 dB/km

• Watsawa ta hanyar amfani da fiber na gani, asarar fiber na gani ba ta dogara da mita ba.

Haɗin yana da mafi girman siginar ɗaukar ƙarfin/bandwidth, har zuwa DC zuwa 40GHz

• Tsangwama daga hana lantarki (EMI) (Babu tasirin sigina a cikin mummunan yanayi)

• Ƙarancin farashi a kowace mita • Zaren gani sun fi sassauƙa da sauƙi, suna da nauyin kusan 1/25 na jagororin raƙuman ruwa da 1/10 na kebul na coaxial

• Tsarin da ya dace kuma mai sassauƙa (don tsarin daukar hoto na likita da na inji)

Dangane da abun da ke cikin na'urar watsawa ta gani, tsarin RF over fiber ya kasu kashi biyu: daidaitawa kai tsaye da daidaitawa ta waje. Mai watsawa ta gani na tsarin RF over fiber kai tsaye yana amfani da laser DFB kai tsaye, wanda ke da fa'idodin ƙarancin farashi, ƙaramin girma da sauƙin haɗawa, kuma an yi amfani da shi sosai. Duk da haka, an iyakance shi da guntu na laser DFB kai tsaye, ana iya amfani da RF mai daidaitawa kai tsaye akan fiber ne kawai a cikin mitar da ke ƙasa da 20GHz. Idan aka kwatanta da daidaitawa kai tsaye, mai watsawa ta waje RF akan fiber na gani ya ƙunshi laser DFB mai mita ɗaya da mai daidaitawa ta lantarki. Saboda balagar fasahar mai daidaitawa ta lantarki, tsarin daidaitawa na waje RF akan fiber na iya cimma aikace-aikace a cikin mitar da ta fi 40GHz girma. Duk da haka, saboda ƙarinna'urar sarrafa na'urar lantarki (electro-optical modulator), tsarin ya fi rikitarwa kuma ba ya da amfani ga aikace-aikace. Ribar haɗin ROF, siffar hayaniya da kewayon motsi muhimman sigogi ne na hanyoyin haɗin ROF, kuma akwai haɗin kai tsakanin ukun. Misali, ƙaramin adadi na hayaniya yana nufin babban kewayon motsi, yayin da babban riba ba wai kawai ake buƙata ta kowace tsarin ba, har ma yana da babban tasiri ga sauran fannoni na aikin tsarin.