Hoʻolauna kēia mokuna i nā ʻano kumu o ke kamaʻilio uea ʻole, me ka manaʻo e hāʻawi i kahi ʻike maikaʻi aʻe i ke kuleana o nā antennas i nā ʻōnaehana kamaʻilio. Hana ʻia ke kamaʻilio uea ʻole ma ke ʻano o nā nalu electromagnetic, e pono ai ke hoʻomaopopo i nā ʻano hoʻolaha o nā nalu.
Ma kēia mokuna, e kūkākūkā mākou i nā palena aʻe:
•Pono pinepine
•Lōʻihi o ka nalu
•Hoʻohālikelike Impedance
•VSWR & Mana Hoʻohuli ʻia
•Ka laulā o ka bandwidth
•Pakeneka Bandwidth
•Ka ikaika o ka pāhawewe
I kēia manawa, e nānā pono kākou iā lākou.
Alapine (frequency)
Wahi a ka wehewehe maʻamau, ʻo ke alapine (frequency) ka helu o nā hana hou ʻana o kahi nalu i kēlā me kēia manawa. Ma nā huaʻōlelo maʻalahi, wehewehe ke alapine (frequency) i ka pinepine o kahi hanana. Hana hou ʻia kahi nalu periodic i kēlā me kēia T kekona (hoʻokahi wā), a ʻo kona alapine (frequency) ka reciprocal o ka manawa T.
Ma ke ʻano makemakika, penei ka ʻike ʻia:
$$f = \frac{1}{T}$$
•Hōʻike ʻo F i ke alapine (frequency) o kahi nalu periodic, ʻoiai
•ʻO T ka manawa e pono ai e hoʻopau i hoʻokahi pōʻaiapuni piha.
Ua ana ʻia ke alapine (frequency) ma hertz, i hoʻopōkole ʻia ʻo Hz.
Hōʻike ke kiʻi ma luna i kahi nalu sine, e hoʻolālā ana i ka voltage (ma mV) ma ke ʻano he hana o ka manawa (ma ms). Hana hou kēia ʻano nalu i kēlā me kēia 2t milliseconds; no laila, ʻo kona wā T = 2t ms, a ʻo kona alapine (frequency) f = 1/(2t) kHz.
Ka lōʻihi o ka nalu
Wahi a ka wehewehena maʻamau, ua kapa ʻia ka mamao ma waena o ʻelua mau piko i ka lālani a i ʻole ʻelua mau ʻauwai i ka lālani ka nalu.
I ka ʻōlelo maʻalahi, ʻo ka nalu ka mamao ma waena o ʻelua mau piko maikaʻi e pili kokoke ana a i ʻole ʻelua mau piko maikaʻi ʻole e pili kokoke ana. Hōʻike ke kiʻi ma lalo nei i kahi nalu manawa, me ka nalu (λ) a me ka amplitude i hōʻailona ʻia. ʻO ke kiʻekiʻe o ke alapine (frequency), ʻo ka pōkole o ka nalu, a ʻo ka hope.
ʻO ke ʻano hana no ka nalu:
$$\lambda = \frac{c}{f}$$
•Hōʻike ʻo λ i ka nalu
ʻO C ka wikiwiki o ka mālamalama ($3 \times 10^8$ mika i kekona)
•ʻO F ke alapine (frequency)
Hōʻike ʻia ka nalu λ ma nā anakahi o ka lōʻihi, e like me nā mika, nā kapuaʻi, a i ʻole nā ʻīniha. ʻO ke anakahi i hoʻohana pinepine ʻia ʻo ia ka mika.
Hoʻohālikelike Impedance:
Wahi a ka wehewehe maʻamau, hana ʻia ka hoʻohālikelike impedance ke like ka impedance o ka transmitter me ka impedance o ka mea loaʻa.
Pono ka hoʻohālikelike ʻana o ka impedance ma waena o ka antenna a me ke kaapuni. Pono e hoʻohālikelike ʻia nā impedances o ka antenna, ka laina hoʻoili, a me ke kaapuni e hoʻokō ai i ka hoʻoili mana kiʻekiʻe loa ma waena o ka antenna a me ka mea loaʻa a i ʻole ka mea hoʻoili.
Ka Pono o ke Kūlike ʻana
Hiki i nā mea hana resonant ke hāʻawi i ka hoʻopuka kūpono i loko o kekahi mau alapine narrowband. Ma ke ʻano he mea hana resonant, hiki i kahi antenna ke hoʻokō i ka hana hoʻopuka maikaʻi aʻe ke hoʻohālikelike pono ʻia kona impedance.
•Ke kūlike ka impedance antenna me ka impedance o ka hakahaka manuahi, e hoʻoili pono ʻia ka mana i hoʻopuka ʻia e ka antenna
•No kahi antenna hoʻokipa, pono e kūlike kona impedance hoʻopuka me ka impedance hoʻokomo o ke kaapuni amplifier hoʻokipa
•No kahi antenna hoʻoili, pono e kūlike kona impedance hoʻokomo me ka impedance hoʻopuka o ka amplifier hoʻoili a me ka impedance ʻano o ka laina hoʻoili.
Ua ana ʻia ka impedance ma ohms, i hōʻike ʻia e ka hōʻailona Z.
VSWR & Mana i Hōʻike ʻia：
Wahi a ka wehewehe maʻamau, ua kapa ʻia ka lakio o ke ana wela kiʻekiʻe loa i ke ana wela haʻahaʻa loa i loko o kahi nalu kū ʻo ia ka lakio nalu kū voltage (VSWR).
Ke kūlike ʻole nā impedances o ka antenna, ka laina hoʻouna, a me ke kaapuni, ʻaʻole hiki ke hoʻolaha pono ʻia ka mana; akā, ua hoʻihoʻi ʻia kahi hapa o ka mana.
ʻO nā ʻano nui -
•ʻO ke anakahi e hōʻike ana i ke kekelē o ka impedance mismatch ua kapa ʻia ʻo Voltage Standing Wave Ratio (VSWR)
•ʻO VSWR ke kū nei no Voltage Standing Wave Ratio a ua kapa pinepine ʻia hoʻi ʻo SWR
•ʻO ka nui o ka impedance mismatch, ʻo ke kiʻekiʻe o ka waiwai VSWR
•No ka hoʻokō ʻana i ka radiation kūpono, ʻo ka waiwai VSWR kūpono he 1:1
•ʻO ka mana i hōʻike ʻia e pili ana i ka hapa o ka mana i mua i hoʻonele ʻia. ʻO ka mana i hōʻike ʻia a me VSWR e wehewehe ana i ka hanana kino like mai nā manaʻo like ʻole
Ka laulā o ka bandwidth:
Wahi a ka wehewehe maʻamau, ʻo ke kaula alapine (frequency band) i loko o kahi pae nalu i kuhikuhi ʻia no kahi kamaʻilio kikoʻī ua kapa ʻia ʻo bandwidth.
Ke hoʻouna ʻia a loaʻa paha kahi hōʻailona, hana ia i loko o kahi laulā alapine (frequency). Hoʻokaʻawale ʻia kēia laulā alapine (frequency) kikoʻī i kahi hōʻailona kikoʻī e pale aku i ka hoʻopilikia ʻia mai nā hōʻailona ʻē aʻe i ka wā o ka hoʻouna ʻana.
•ʻO ka bandwidth e pili ana i ka laulā alapine (frequency) ma waena o nā palena alapine kiʻekiʻe a me ke alapine haʻahaʻa o kahi hoʻoili hōʻailona
•Ke hoʻokaʻawale ʻia ka bandwidth, ʻaʻole hiki ke hoʻohana ʻia e kekahi poʻe ʻē aʻe
•Ua māhele ʻia ke ʻano holoʻokoʻa i nā ʻāpana bandwidth, i hāʻawi ʻia kēlā me kēia i nā mea hoʻoili like ʻole
Hiki ke kapa ʻia ka bandwidth a mākou i kūkākūkā ai he bandwidth absolute.
Pākēneka Bandwidth：
Wahi a ka wehewehe maʻamau, ua kapa ʻia ka lakio o ka bandwidth paʻa i kona alapine waena ʻo ka bandwidth pakeneka.
ʻO ke alapine (frequency) i loko o kahi hui kahi i hiki ai ka ikaika o ka hōʻailona i kona kiʻekiʻe loa ua kapa ʻia ʻo ke alapine resonant, i ʻike ʻia hoʻi ʻo ke alapine waena o ke hui, i hōʻike ʻia ʻo fC.
•Ua hōʻike ʻia nā alapine kiʻekiʻe a me nā alapine haʻahaʻa o ke kāʻei he fH a me fL, kēlā me kēia
•Hāʻawi ʻia ka bandwidth piha e fH − fL
•No ka loiloi ʻana i ka laulā o kahi hui alapine (frequency band), pono e helu i kona bandwidth hapa a i ʻole ka bandwidth pakeneka
Ua helu ʻia ka pakeneka o ka bandwidth e hoʻomaopopo i ka laulā o nā loli alapine (frequency) e hiki ai i kahi ʻāpana a ʻōnaehana paha ke lawelawe.
•H hōʻike i ke alapine kiʻekiʻe
•Hōʻike ʻo fL i ke alapine haʻahaʻa
•fc hōʻike i ke alapine waena
ʻO ka nui o ka pakeneka o ka bandwidth, ʻo ka laulā o ka bandwidth o ke kahawai.
Ka ikaika o ka pāhawewe：
Ua wehewehe ʻia ka ikaika o ka pāhawewe ʻo ia ka mana i pāhawewe ʻia no kēlā me kēia anakahi kihi paʻa.
Hoʻolaha ikaika aku kahi antenna i kekahi mau kuhikuhi, e kūlike ana i kona ikaika radiation kiʻekiʻe loa. Hōʻike ʻia ka laulā radiation kiʻekiʻe loa e ka ikaika radiation.
Hōʻike Makemakika
Loaʻa ka ikaika o ka radiation ma ka hoʻonui ʻana i ka nui o ka mana i hoʻomālamalama ʻia e ka huinahā o ka mamao radial:
Ma kahi ʻo U ka ikaika o ka radiation, ʻo r ka mamao radial, a ʻo （Wrad） ka nui o ka mana i hoʻoheheʻe ʻia.
•Hōʻike ʻo U i ka ikaika o ka radiation
•hōʻike ʻo r i ka mamao radial
•Hōʻike ʻo Wrad i ka nui o ka mana i hoʻopuehu ʻia
Hōʻike ka hoʻohālikelike ma luna nei i ka ikaika o ka radiation o ka antenna. I kekahi manawa ua hōʻike ʻia ka mamao radial e ka hōʻailona Φ.
ʻO ke anakahi o ka ikaika o ka pāhawewe he watts no steradian (W/sr), a i ʻole watts no ka radian kuea (W/rad²).
No ka ʻike hou aku e pili ana i nā antennas, e kipa i ka pūnaewele:
Ka manawa hoʻouna: Malaki-26-2026
