He tawhā matua te aronga o te pūihi. He ine tēnei mō te āhua o te tauira irahiko o te pūihi aronga. Ko te pūihi e horapa ōrite ana ki ngā taha katoa, ka rite tōna aronga ki te 1. (He ōrite tēnei ki te kore tiēpere -0 dB).
Ka taea te tuhi i te mahi a ngā taunga porowhita hei tauira irahiko kua whakatauritea:
[Whārite 1]
He rite te āhua o te tauira irahiko kua whakatauritea ki te tauira irahiko taketake. Ka whakaitihia te rahi o te tauira irahiko kua whakatauritea kia rite te uara mōrahi o te tauira irahiko ki te 1. (Ko te mea nui rawa ko te whārite [1] o "F"). Mā te pāngarau, ka tuhia te tātai mō te ahunga (momo "D") penei:
Tērā pea he whārite ahunga uaua tēnei. Heoi, ko ngā tauira irahiko o ngā ngota te mea nui rawa atu. Ko te tauwehenga te tohu o te mana toharite e irahikohia ana i ngā taha katoa. Ko te whārite he ine i te mana tihi irahikohia i wehea ki te toharite. Mā tēnei ka puta te aronga o te pūihi.
Tauira aronga
Hei tauira, whakaarohia ngā whārite e rua e whai ake nei mō te tauira irahiko o ngā pūihi e rua.
Pūihi 1
Pūihi 2
Kei te Pikitia 1 ēnei tauira irahiko. Kia mōhio koe ko te aratau irahiko he mahi noa iho o te koki porotaka theta(θ). Ehara te tauira irahiko i te mahi o te azimuth. (Kāore anō kia rerekē te tauira irahiko azimuthal). He iti ake te ahunga o te tauira irahiko o te pūihi tuatahi, i tērā o te tauira irahiko o te pūihi tuarua. Nō reira, e matapaetia ana ka iti ake te ahunga mō te pūihi tuatahi.
ahua 1. Te hoahoa tauira irahiko o te pūihi. He teitei te ahunga?
Mā te whakamahi i te tātai [1], ka taea e tātou te tatau he teitei ake te aronga o te pūihi. Hei tirotiro i tō māramatanga, whakaarohia te Pikitia 1 me te aha te aronga. Kātahi ka whakatau ko tēhea pūihi he teitei ake te aronga me te kore e whakamahi i tētahi pāngarau.
Ngā hua tātai aronga, whakamahia te tātai [1]:
Tātaitanga antenna ahunga 1, 1.273 (1.05 dB).
Te tātaitanga o te pūihi ahunga 2, 2.707 (4.32 dB).
Ko te pikinga o te aronga tika he tikanga kia arotahi ake, kia anga whakamua ake rānei te pūihi. Ko te tikanga o tēnei, he 2.707 ngā wā o te kaha ahunga o te pūihi whiwhi-rua i tōna tihi i te pūihi ahunga-katoa. Ka whiwhi te pūihi 1 i te 1.273 ngā wā o te kaha o te pūihi ahunga-katoa. Ka whakamahia ngā pūihi ahunga-katoa hei tohutoro noa ahakoa kāore he pūihi isotropic.
Me iti te ahunga o ngā pūihi waea pūkoro nā te mea ka taea e ngā tohu te puta mai i ngā taha katoa. He rerekē, he nui te ahunga o ngā rihi amiorangi. Ka whiwhi tohu te rihi amiorangi mai i tētahi ahunga pumau. Hei tauira, ki te whiwhi koe i tētahi rihi pouaka whakaata amiorangi, ka kī atu te kamupene ki a koe me pēhea te tohu, ā, ka whiwhi te rihi i te tohu e hiahiatia ana.
Ka mutu tā mātou me te rārangi o ngā momo pūihi me ō rātou ahunga. Mā tēnei ka hoatu he whakaaro ki a koe mō te ahunga e kitea whānuitia ana.
Momo pūihi Te ahunga noa Te ahunga noa [decibel] (dB)
Pūihi poto-rua 1.5 1.76
Pūihi haurua-ngaru 1.64 2.15
Pātaki (pūihi miro-whiri) 3.2-6.3 5-8
Pūnaha haona 10-100 10-20
Pūihi rihi 10-10,000 10-40
E whakaatu ana ngā raraunga i runga ake nei he rerekē rawa te ahunga o te pūihi. Nō reira, he mea nui kia mārama ki te ahunga i te wā e whiriwhiri ana i te pūihi pai rawa atu mō tō tono motuhake. Mena me tuku, me whiwhi rānei koe i te pūngao mai i ngā ahunga maha i te ahunga kotahi, me hoahoa e koe he pūihi he ahunga iti. Ko ngā tauira o ngā tono mō ngā pūihi ahunga iti ko ngā reo irirangi motuka, ngā waea pūkoro, me te urunga Ipurangi ahokore rorohiko. I tetahi atu taha, ki te mea kei te mahi koe i te tirotiro mamao, i te whakawhiti hiko kua arotahi rānei, ka hiahiatia he pūihi ahunga tino teitei. Ka whakanuia e ngā pūihi ahunga tino teitei te whakawhiti hiko mai i te ahunga e hiahiatia ana, ā, ka whakaitihia ngā tohu mai i ngā ahunga kāore e hiahiatia.
Me pēhea tātou e hiahia ana ki tētahi pūihi aronga iti?
Ko te ture whānui o te ariā pūihi, me iti te hiko o te pūihi hei whakaputa i te ahunga iti. Arā, ki te whakamahi koe i te pūihi me te rahi katoa o te roangaru 0.25 - 0.5, ka whakaitihia te ahunga. Ko ngā pūihi haurua-ngaru rua-ngaru, ngā pūihi mokowā haurua-roa-ngaru rānei, he iti iho i te 3 dB te ahunga. He iti rawa tēnei i te ahunga ka taea e koe te whiwhi i roto i te mahi.
Hei whakamutunga, kāore e taea te hanga i ngā pūihi kia iti iho i te hauwhā ngaru me te kore e whakaiti i te whai huatanga o te pūihi me te whānui o te pūihi. Ka matapakihia te whai huatanga o te pūihi me te whānui o te pūihi i ngā upoko o muri mai.
Mō tētahi pūihi he nui te ahunga, ka hiahiatia he pūihi o ngā rahi roangaru maha. He nui te ahunga o ngā pūihi rihi amiorangi me ngā pūihi haona. Nā te mea he maha ngā roangaru o ēnei pūihi.
He aha rā te take? Hei whakamutunga, ko te take e pā ana ki ngā āhuatanga o te panoni Fourier. Ina tangohia e koe te panoni Fourier o tētahi pāoro poto, ka whiwhi koe i tētahi whānuitanga whānui. Kāore tēnei kupu whakarite i roto i te whakatau i te tauira irahiko o tētahi pūihi. Ka taea te whakaaro ko te tauira irahiko te panoni Fourier o te tohatoha o te iahiko, te ngaohiko rānei i te taha o te pūihi. Nō reira, he whānui ngā tauira irahiko o ngā pūihi iti (me te iti o te ahunga). Ngā pūihi me te tohatoha ngaohiko, iahiko rānei ōrite nui He tauira tino ahunga (me te ahunga teitei).
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Wā tuku: Whiringa-ā-rangi-07-2023
