Loaʻa i ka puka ma loko iho ka mana parasitic i ka lepo. Inā ʻike ʻia ke anawaena o ka puka hoʻokaʻawale ma ka papahele papahele o ka puka puka ʻo D2, ʻo D1 ke anawaena o ka pā ma waena o ka puka, ʻo ka mānoanoa o ka papa PCB ʻo T, a ʻo ka dielectric mau o ka papa substrate. ʻO ε, ʻO ka mana parasitic o ka via ma kahi o C=1.41 ε TD1/(D2-D1)
ʻO ka hopena nui o ka capacitance parasitic ma ke kaapuni i hana ʻia e vias ʻo ia ka mea e hoʻolōʻihi i ka manawa hōʻailona a hoʻemi i ka wikiwiki o ke kaapuni. No ka laʻana, no ka papa PCB me ka mānoanoa o 50 Mil, inā hoʻohana ʻia kahi vias me ke anawaena o loko o 10 Mil a me ke anawaena pad o 20 Mil, a ʻo ka mamao ma waena o ka pā a me ka ʻāpana keleawe ma ka honua he 32 Mil. , hiki iā mākou ke helu i ka capacitance parasitic o nā vias me ka hoʻohana ʻana i ke ʻano o luna e like me kēia: C=1.41 x 4.4x 0.050 x 0.020/(0.032-0.020)=0.517pF, ʻO ka hoʻololi ʻana o ka manawa piʻi i hana ʻia e kēia capacitance: T10-90 =2.2C (Z0/2)=2.2x0.517x (55/2)=31.28ps. Mai kēia mau waiwai, hiki ke ʻike ʻia ʻoiai ʻaʻole nui ka hopena o ka capacitance parasitic o kahi via hoʻokahi i ka hoʻolohi ʻana i ka piʻi ʻana, pono e mālama ʻia inā hoʻohana ʻia nā vias i nā manawa he nui i ka uwea no ka hoʻololi ʻana i ka interlayer.
Me ka capacitance parasitic i loko o ke ala, aia kekahi inductance parasitic. Hoʻonāwaliwali ka inductance inductance i ka hāʻawi ʻana o ka capacitance bypass a hoʻonāwaliwali i ka pono kānana o ka ʻōnaehana mana holoʻokoʻa. Hiki ke hoʻohana ʻia ke ʻano ma lalo nei no ka helu ʻana i kahi inductance parasitic kokoke i ke ala:
L=5.08h [ln (4h/d)+1], kahi L e pili ana i ka inductance o ka puka ma, h ka loa o ka puka ma, a o d ke anawaena o ka lua wili waena. Mai ka hoʻohālikelike, hiki ke ʻike ʻia he hopena liʻiliʻi ke anawaena o ka via i ka inductance, ʻoiai ʻo ka lōʻihi o ka via ka hopena nui loa i ka inductance. Me ka hoʻohana ʻana i ka laʻana i luna, hiki ke helu ʻia ka inductance o ka via e like me L=5.08x0.050 [ln (4x0.050/0.010)+1]=1.015nH. Inā he 1ns ka manawa piʻi o ka hōʻailona, a laila ʻo kona nui impedance like: XL=π L/T10-90=3.19 Ω.
I ka hōʻuluʻulu ʻana:
ʻO ke koho ʻana i kahi PCB ʻoi aku ka maikaʻi no ka hōʻemi ʻana i nā ʻāpana parasitic
E ho'āʻo e hoʻololi i nā papa a i ʻole e hoʻohana i nā vias pono ʻole no ka hoʻokele hōʻailona
E wili i nā lua ma kahi kokoke i ka lako mana a me ka lepo, a ʻo ka pōkole a me ka mānoanoa o nā wili o nā lua a me nā pine, ʻoi aku ka maikaʻi.
E kau i nā lua honua hou aʻe ma kahi o ka papa hoʻololi hōʻailona e hāʻawi i ke kaapuni kokoke loa no ka hōʻailona
I ka hana ʻana i nā huahana fiber optical, e like me ka module optical,ONU, module fiber optical,OLTmodule, etc., pono ʻoe e noʻonoʻo i ka hopena o ka vias ma ka bosa, ka hoʻouna ʻana i ke kiʻikuhi maka, ka ratio extinction, etc., a i ʻole ka hopena i ka loaʻa ʻana o ka naʻau.
ʻO ka mea i luna nei kahi ʻike pōkole o "Introduction to Key Parameters of BOSA - ma o ka nui (II)", hiki ke hoʻohana ʻia ma ke ʻano he kuhikuhi. He hui ʻenehana ikaika loa kā mākou hui a hiki ke hāʻawi i nā lawelawe ʻenehana loea i nā mea kūʻai aku. I kēia manawa, loaʻa i kā mākou hui nā huahana like ʻole: naʻauaoonu.oltmea lako, Ethernethoʻololia me nā lako pūnaewele ʻē aʻe. Inā makemake ʻoe, hiki iā ʻoe ke aʻo hou e pili ana iā lākou.
