Hoʻomaka i ka RF ma luna o ka ʻōnaehana fiber

Hoʻomaka i ka RF ma luna o ka ʻōnaehana fiber

RF ma luna o ka fiberʻO ia kekahi o nā noi koʻikoʻi o nā kiʻi kiʻi microwave a hōʻike i nā mea maikaʻi ʻole i nā kula kiʻekiʻe e like me ka microwave photonic radar, telephoto radio astronomical, a me ke kamaʻilio kaʻa kaʻa ʻole.

ʻO ka RF ma luna o ka fiberloulou ROFʻO ka mea nui i haku ʻia me nā transmitters optical, nā mea hoʻokipa optical a me nā uwea optical. E like me ka mea i hōʻike ʻia ma ke Kiʻi 1.

ʻO nā mea hoʻolele Optical: Hoʻolaha ʻia nā laser manaʻo (DFB laser) ua hoʻohana ʻia i nā noi haʻahaʻa haʻahaʻa a me nā haʻahaʻa haʻahaʻa, ʻoiai hoʻohana ʻia nā lasers FP i nā noi me nā koi haʻahaʻa. ʻO kēia mau lasers he mau nalu o 1310nm a i ʻole 1550nm.

Optical receiver: Ma ka ʻaoʻao ʻē aʻe o ka loulou fiber optical, ʻike ʻia ke kukui e ka PIN photodiode o ka mea hoʻokipa, nāna e hoʻohuli i ke kukui i kēia manawa.

ʻO nā uwea Optical: He ʻokoʻa i nā fibers multimode, hoʻohana ʻia nā fiber mode hoʻokahi i nā loulou laina ma muli o ko lākou haʻahaʻa haʻahaʻa a me ka haʻahaʻa haʻahaʻa. Ma kahi hawewe nalu o 1310nm, ʻo ka attenuation o ka hōʻailona optical i ka fiber optical he emi iho ma mua o 0.4dB / km. Ma ka 1550nm, emi iho ia ma mua o 0.25dB/km.

ʻO ka loulou ROF kahi ʻōnaehana hoʻouna laina. Ma muli o nā hiʻohiʻona o ka linear transmission a me ka optical transmission, loaʻa i ka loulou ROF nā pono ʻenehana penei:

• Pohō haʻahaʻa loa, me ka attenuation fiber ma lalo o 0.4 dB/km

• ʻO ka fiber optical fiber ultra-bandwidth transmission, kūʻokoʻa ka nalowale o ka fiber optical i ke alapine

Loaʻa i ka loulou kahi hōʻailona kiʻekiʻe e lawe ana i ka mana/bandwidth, a hiki i DC a 40GHz

• ʻAi-electromagnetic interference (EMI) (ʻAʻohe hopena hōʻailona i ka wā ʻino)

• ʻO ke kumu kūʻai haʻahaʻa no kēlā me kēia mika • ʻOi aku ka maʻalahi a me ke kaumaha o nā fiber Optical, ma kahi o 1/25 o nā alakaʻi nalu a me 1/10 o nā kaula coaxial.

• Hoʻolālā maʻalahi a maʻalahi (no nā ʻōnaehana kiʻi olakino a me nā mīkini)

Wahi a ka hoʻokumu ʻana o ka transmitter optical, ua māhele ʻia ka RF ma luna o ka ʻōnaehana fiber i ʻelua ʻano: modulation pololei a me ka modulation waho. ʻO ka transmitter optical o ka RF i hoʻololi pololei ʻia ma luna o ka ʻōnaehana fiber e hoʻohana i ka laser DFB i hoʻololi ʻia, loaʻa nā mea maikaʻi o ke kumukūʻai haʻahaʻa, ka liʻiliʻi liʻiliʻi a me ka hoʻohui maʻalahi, a ua hoʻohana nui ʻia. Eia nō naʻe, kaupalena ʻia e ka chip laser DFB i hoʻololi ʻia, hiki ke hoʻohana ʻia ka RF i hoʻololi ʻia ma luna o ka fiber ma ke alapine ma lalo o 20GHz. Hoʻohālikelike ʻia me ka modulation pololei, ʻo ka modulation waho RF ma luna o ka fiber optical transmitter i haku ʻia me kahi laser DFB hoʻokahi-frequency a me kahi modulator electro-optic. Ma muli o ke oʻo ʻana o ka ʻenehana modulator electro-optic, hiki i ka modulation waho RF ma luna o ka ʻōnaehana fiber ke hoʻokō i nā noi i ka band frequency ʻoi aku ma mua o 40GHz. Eia naʻe, ma muli o ka hoʻohui ʻia o kaelectro-optic modulator, ʻoi aku ka paʻakikī o ka ʻōnaehana a ʻaʻole kūpono i ka noi. ʻO ka loaʻa ʻana o ka loulou ROF, ke kiʻi walaʻau a me ke ʻano ikaika he mau palena koʻikoʻi o nā loulou ROF, a aia kahi pilina pili i waena o nā mea ʻekolu. No ka laʻana, ʻo ka haʻahaʻa haʻahaʻa haʻahaʻa ke ʻano o ka laulā dynamic nui, ʻoiai ʻaʻole koi ʻia ka loaʻa kiʻekiʻe e kēlā me kēia ʻōnaehana, akā ʻoi aku ka hopena i nā ʻano hana ʻē aʻe o ka ʻōnaehana.