Isingeniso ku-RF phezu kwesistimu yefayibha

Isingeniso ku-RF phezu kwesistimu yefayibha

I-RF phezu kwefayibhaingenye yezindlela ezibalulekile zokusebenzisa i-microwave photonics futhi ibonisa izinzuzo ezingenakuqhathaniswa emikhakheni ethuthukile njenge-microwave photonic radar, i-astronomical radio telephoto, kanye nokuxhumana kwezimoto zasemoyeni ezingenamuntu.

I-RF phezu kwefayibhaIsixhumanisi se-ROFYakhiwe kakhulu ngama-transmitter e-optical, ama-optical receiver kanye nama-optical cables. Njengoba kuboniswe kuMfanekiso 1.

Ama-transmitter e-Optical: Ama-laser empendulo asakazwayo (I-laser ye-DFB) zisetshenziswa ezinhlotsheni zomsindo ophansi kanye nezinga eliphezulu, kuyilapho ama-laser e-FP esetshenziswa ezinhlotsheni zomsindo ezinezidingo eziphansi. Lawa ma-laser anama-wavelength angu-1310nm noma angu-1550nm.

Umamukeli we-Optical: Ngakolunye uhlangothi lwesixhumanisi se-optical fiber, ukukhanya kutholwa yi-PIN photodiode yomamukeli, eguqula ukukhanya kube ugesi.

Izintambo ze-optical: Ngokungafani nezintambo ze-multimode, izintambo ze-single-mode zisetshenziswa ezixhumanisweni eziqondile ngenxa yokusabalala kwazo okuphansi kanye nokulahleka okuphansi. Kubude be-wavelength obungu-1310nm, ukuncishiswa kwesignali ye-optical ku-optical fiber kungaphansi kuka-0.4dB/km. Ku-1550nm, kungaphansi kuka-0.25dB/km.

Isixhumanisi se-ROF siwuhlelo lokudlulisa oluqondile. Ngokusekelwe ezicini zokudlulisa okuqondile kanye nokudlulisa okubonakalayo, isixhumanisi se-ROF sinezinzuzo zobuchwepheshe ezilandelayo:

• Ukulahlekelwa okuphansi kakhulu, kanye nokuncipha kwefayibha okungaphansi kuka-0.4 dB/km

• Ukudluliselwa kwe-ultra-bandwidth yefayibha ye-optical, ukulahleka kwefayibha ye-optical akuxhomekile emvamisa

Isixhumanisi sinomthamo/ububanzi besignali obuphezulu, kufika ku-DC kuya ku-40GHz

• Ukuphazamiseka kwe-anti-electromagnetic (EMI) (Akukho mthelela wesignali esimweni sezulu esibi)

• Izindleko eziphansi ngemitha • Imicu ye-optical iguquguquka kakhudlwana futhi ilula, inesisindo esingaba yi-1/25 yama-waveguides kanye ne-1/10 yezintambo ze-coaxial

• Ukuhlelwa okulula nokuguquguqukayo (kwezinhlelo zezithombe zezokwelapha nezemishini)

Ngokusho kokwakheka kwe-optical transmitter, uhlelo lwe-RF over fiber luhlukaniswe ngezinhlobo ezimbili: i-direct modulation kanye ne-external modulation. I-optical transmitter ye-direct-modulated RF over fiber system isebenzisa i-direct-modulated DFB laser, enezinzuzo zezindleko eziphansi, usayizi omncane kanye nokuhlanganiswa okulula, futhi isetshenziswe kabanzi. Kodwa-ke, inqunyelwe yi-direct-modulated DFB laser chip, i-direct-modulated RF over fiber ingasetshenziswa kuphela kubhendi yemvamisa engaphansi kwama-20GHz. Uma kuqhathaniswa ne-direct modulation, i-external modulation RF over fiber optical transmitter yakhiwe yi-single-frequency DFB laser kanye ne-electro-optic modulator. Ngenxa yokuvuthwa kobuchwepheshe be-electro-optic modulator, uhlelo lwe-external modulation RF over fiber lungafeza izinhlelo zokusebenza kubhendi yemvamisa engaphezu kwama-40GHz. Kodwa-ke, ngenxa yokwengezwa kwei-electro-optic modulator, uhlelo luyinkimbinkimbi kakhulu futhi alukwazi ukusetshenziswa. Ukwanda kwesixhumanisi se-ROF, isibalo somsindo kanye nobubanzi obuguqukayo kuyimingcele ebalulekile yezixhumanisi ze-ROF, futhi kukhona ukuxhumana okuseduze phakathi kwalokhu okuthathu. Isibonelo, isibalo somsindo ophansi sisho ububanzi obukhulu obuguqukayo, kuyilapho inzuzo ephezulu ingadingeki yiwo wonke uhlelo kuphela, kodwa futhi inomthelela omkhulu kwezinye izici zokusebenza kwesistimu.