Chidziwitso cha RF pa fiber System

Chidziwitso cha RF pa fiber System

RF pa fiberndi imodzi mwazinthu zofunika kwambiri pakugwiritsa ntchito ma microwave photonics ndipo imawonetsa zabwino zosayerekezeka m'magawo apamwamba monga microwave photonic radar, astronomical radio telephoto, ndi kulumikizana kosayendetsedwa ndi ndege zam'mlengalenga.

RF pa fiberChithunzi cha ROFmakamaka amapangidwa ndi ma transmitters owoneka bwino, zolandila ndi zingwe za kuwala. Monga momwe chithunzi 1 chikusonyezera.

Ma transmitters owoneka: ma lasers ogawa mayankho (DFB laser) amagwiritsidwa ntchito popanga phokoso laling'ono komanso lamphamvu kwambiri, pamene ma lasers a FP amagwiritsidwa ntchito pazofunikira zochepa. Ma lasers awa ali ndi kutalika kwa 1310nm kapena 1550nm.

Optical receiver: Kumapeto ena a ulalo wa fiber optical, kuwalako kumadziwika ndi PIN photodiode ya wolandila, yomwe imatembenuza kuwala kukhala komweko.

Zingwe za Optical: Mosiyana ndi ulusi wa multimode, ulusi wamtundu umodzi umagwiritsidwa ntchito pamalumikizidwe amzere chifukwa chakuchepa kwawo komanso kutayika kochepa. Pa kutalika kwa 1310nm, kuchepetsedwa kwa chizindikiro cha kuwala mu fiber fiber ndi osachepera 0.4dB / km. Pa 1550nm, ndi yocheperapo 0.25dB/km.

Ulalo wa ROF ndi njira yotumizira ma linear. Kutengera mawonekedwe a kufalikira kwa mzere komanso kufalikira kwa kuwala, ulalo wa ROF uli ndi izi zabwino mwaukadaulo:

• Kutayika kochepa kwambiri, ndi kuchepa kwa fiber pansi pa 0.4 dB / km

• Kutumiza kwa fiber ultra-bandwidth, kutayika kwa fiber kumadalira pafupipafupi

Ulalowu uli ndi mphamvu yonyamula ma siginolo / bandwidth, mpaka DC mpaka 40GHz

• Anti-electromagnetic interference (EMI) (Palibe chizindikiro chokhudza nyengo yoipa)

• Mtengo wotsika pa mita imodzi • Ulusi wowala ndi wosinthasintha komanso wopepuka, wolemera pafupifupi 1/25 ya ma waveguides ndi 1/10 ya zingwe za coaxial

• Maonekedwe osavuta komanso osinthika (amakakina azachipatala ndi makina ojambulira)

Malinga ndi kapangidwe ka makina opangira magetsi, RF pa fiber system imagawidwa m'mitundu iwiri: kusinthasintha kwachindunji ndi kusinthasintha kwakunja. Ma transmitter opangidwa ndi RF modulated mwachindunji pa fiber system amatengera DFB laser yokhazikika, yomwe ili ndi zabwino zake zotsika mtengo, zazing'ono komanso kuphatikiza kosavuta, ndipo yakhala ikugwiritsidwa ntchito kwambiri. Komabe, mocheperako ndi chipangizo cha DFB laser chip, RF yokhazikika pa fiber ingagwiritsidwe ntchito pa frequency band yomwe ili pansi pa 20GHz. Poyerekeza ndi kusinthasintha kwachindunji, kusintha kwakunja kwa RF pa fiber optical transmitter kumapangidwa ndi laser-frequency DFB laser ndi electro-optic modulator. Chifukwa cha kukhwima kwaukadaulo wa ma electro-optic modulator, RF yosinthira pa fiber system imatha kugwiritsa ntchito ma frequency band kuposa 40GHz. Komabe, chifukwa cha kuwonjezera kwaelectro-optic modulator, dongosololi ndi lovuta kwambiri komanso losavuta kugwiritsa ntchito. Kupindula kwa ulalo wa ROF, chiwonetsero chaphokoso ndi mawonekedwe osinthika ndi magawo ofunikira a maulalo a ROF, ndipo pali kulumikizana kwapakati pakati pa atatuwo. Mwachitsanzo, chiwerengero chochepa cha phokoso chimatanthawuza kusinthasintha kwakukulu, pamene kupindula kwakukulu sikungofunika kokha ndi dongosolo lililonse, komanso kumakhudza kwambiri machitidwe ena a machitidwe.