Ko te pōraihana tētahi o ngā āhuatanga matua o ngā pūihi. Me mārama tuatahi tātou ki te pōraihana o ngā ngaru papatahi. Kātahi ka taea e tātou te matapaki i ngā momo matua o te pōraihana o te pūihi.
te whakapōreareatanga rārangi
Ka tīmata tātou ki te mārama ki te whakapororaru o te ngaru hikohiko papatahi.
He maha ngā āhuatanga o te ngaru hiko papatahi (EM). Ko te tuatahi, ka haere te mana i te taha kotahi (kāore he āpure e rerekē ana i ngā taha e rua). Tuarua, he poutū te āpure hiko me te āpure aukume tetahi ki tetahi, ā, he poutū hoki tetahi ki tetahi. He poutū te āpure hiko me te āpure aukume ki te taha o te horapa o te ngaru papatahi. Hei tauira, whakaarohia he āpure hiko auau-kotahi (āpure E) e homai ana e te whārite (1). Kei te haere te āpure aukume i te taha +z. Kei te taha +x te taha. Kei te taha +y te taha aukume.
I roto i te whārite (1), tirohia te tuhipoka: . He ira kotahi tēnei (he ira roa), e kī ana kei te ahunga x te pūwāhi o te papa hiko. Kei te whakaatuhia te ngaru papatahi i te Pikitia 1.
ahua 1. He whakaaturanga whakairoiro o te papa hiko e haere ana i te ahunga +z.
Ko te pōraihana te āhua o te tohu me te horapa (contour) o tētahi papa hiko. Hei tauira, whakaarohia te whārite papa hiko ngaru papa (1). Ka tirohia e tātou te tūranga kei reira te papa hiko (X,Y,Z) = (0,0,0) hei mahi a te wā. Ko te kaha o tēnei papa kua tuhia ki te Pikitia 2, i ētahi wā o te wā. Kei te wiri te papa i te auau "F".
ahua 2. Tirohia te papa hiko (X, Y, Z) = (0,0,0) i ngā wā rerekē.
Ka kitea te mara hiko i te pūtake, e hurihuri ana i te kaha whakamuri, whakamuri. Kei te taha tonu o te tuaka-x kua tohua te mara hiko. Nā te mea kei te taha kotahi te rārangi o te mara hiko, ka taea te kī he porowhita rārangi tēnei mara. Hei tāpiri, ki te mea he whakarara te tuaka-X ki te whenua, ka whakaahuahia hoki tēnei mara he porowhita whakapae. Ki te mea kei te taha o te tuaka-Y te aronga o te mara, ka taea te kī he porowhita poutū te ngaru.
Kāore e hiahiatia kia anga whakarara ngā ngaru porotaka rārangi i runga i te tuaka whakapae, poutū rānei. Hei tauira, ko te ngaru hiko me te here e takoto ana i te rārangi e whakaaturia ana i te Pikitia 3 ka porotaka rārangi anō hoki.
ahua 3. Ko te kaha o te papa hiko o tētahi ngaru porotaka rārangi ko tōna ara he koki.
Ka taea te whakaahua i te papa hiko i te Pikitia 3 mā te whārite (2). Inaianei he wāhanga x me y o te papa hiko. He rite te rahi o ngā wāhanga e rua.
Kotahi te mea hei mōhio māu mō te whārite (2) ko te wāhanga-xy me ngā mara hiko i te wāhanga tuarua. Ko te tikanga he rite tonu te kaha o ngā wāhanga e rua i ngā wā katoa.
te porowhita porowhita
Inaianei, me kī ko te papa hiko o te ngaru papatahi e hoatu ana e te whārite (3):
I tēnei take, e 90 nekehanga te rerekētanga o ngā huānga-X me Y. Mēnā ka kitea anō te mara (X, Y, Z) = (0,0,0) pērā i mua, ka puta te pihi mara hiko ki te wā e whakaaturia ana i raro nei i te Pikitia 4.
Pikitia 4. Te kaha o te mara hiko (X, Y, Z) = (0,0,0) rohe EQ. (3).
Ka huri te papa hiko i te Pikitia 4 i roto i te porowhita. Ka whakaahuatia tēnei momo papa hei ngaru porowhita-polarized. Mō te polarization porowhita, me tutuki ngā paearu e whai ake nei:
- Paerewa mō te porowhita porowhita
- Me rua ngā wāhanga poutū (tūhonohono) o te papa hiko.
- Me ōrite te kaha o ngā wāhanga orthogonal o te mara hiko.
- Me 90 nekehanga te koki o ngā wāhanga tapawhā.
Ki te haere i runga i te mata o te Wave Figure 4, ka kiia te hurihanga o te mara he porowhita matau-karaka, he porowhita matau-ringa-polarized (RHCP). Ki te hurihia te mara ki te taha matau-karaka, ka porowhita maui-ringa-polarization te mara (LHCP).
Te porowhita porowhita
Mena e rua ngā wāhanga poutū o te papa hiko, he 90 nekehanga te tawhiti engari he ōrite te rahi, ka porowhita te papa. Ina whakaarohia te papa hiko o te ngaru rererangi e haere ana i te ahunga +z, e whakaahuatia ana e te Whārite (4):
Kei te Pikitia 5 te wāhi noho o te pūwāhi e whakaarohia ai te pito o te whārite hiko.
Pikitia 5. Te mara hiko o te ngaru porowhita porowhita. (4).
Ko te mara i te Pikitia 5, e haere ana i te taha whakamuri, ka rite ki te porowhita matau mēnā ka haere ki waho o te mata. Mēnā ka huri te ira o te mara hiko ki te taha whakamuri, ka porowhita maui te mara.
Hei tāpiri atu, ko te porowhita porowhita e pā ana ki tōna āhua porowhita. Ko te ōwehenga o te āhua porowhita ki te kaha o ngā tuaka matua me ngā tuaka iti. Hei tauira, ko te āhua porowhita o te ngaru mai i te whārite (4) ko 1/0.3= 3.33. Ko ngā ngaru porowhita porowhita ka whakaahuahia anō e te ahunga o te tuaka matua. Ko te whārite ngaru (4) he tuaka kei roto ko te tuaka-x. Kia mahara ka taea te noho o te tuaka matua i tētahi koki papatahi. Kāore e hiahiatia te koki kia uru ki te tuaka X, Y, Z rānei. Hei whakamutunga, he mea nui kia mōhio ko te porowhita porowhita me te porowhita raina he take motuhake o te porowhita porowhita. 1.0 he ngaru porowhita porowhita porowhita porowhita te ngaru porowhita porowhita. Ngā ngaru porowhita porowhita me te āhua porowhita mutunga kore. Ngā ngaru porowhita raina.
Te whakapolarisasi o te pūihi
Nā te mea kua mōhio tātou ki ngā mara hikohiko o te ngaru papa porowhita, kua māmā noa iho te tautuhi i te porowhita o te pūihi.
Te Whakapūtanga o te Pūihi He aromatawai i te mara tawhiti o te pūihi, te whakapūtanga o te mara irahikohia. Nō reira, he maha ngā wā ka whakarārangihia ngā pūihi hei "pūihi whakapūtanga raina" "pūihi whakapūtanga porowhita matau rānei".
He mea nui tēnei ariā māmā mō ngā whakawhitiwhitinga antenna. Tuatahi, kāore te antenna whakapae-polarized e whakawhitiwhiti kōrero ki te antenna whakapae-polarized poutū. Nā te ariā tauutuutu, ka tuku me te whiwhi te antenna i te ara kotahi. Nō reira, ka tuku me te whiwhi ngā antenna whakapae-polarized poutū i ngā mara whakapae-polarized poutū. Nō reira, ki te ngana koe ki te tuku i tētahi antenna whakapae-polarized poutū, kāore he whiwhinga.
I te nuinga o te wā, mō ngā pūihi porowhita rārangi e rua e hurihia ana tetahi ki tetahi mā te koki ( ), ka whakaahuahia te ngaronga mana nā tēnei koretake o te porowhita e te tauwehenga ngaronga porowhita (PLF):
Nō reira, ki te rite te pōraihana o ngā pūihi e rua, ko te koki i waenganui i ō rāua mara irahiko e whiti ana he kore, ā, kāore he ngaronga mana nā te kore ōrite o te pōraihana. Ki te pōraihana poutū tētahi pūihi, ā, pōraihana whakapae tētahi, ko te koki he 90 nekehanga, ā, kāore he mana e whakawhitia.
TUHI: Mā te neke i te waea ki runga ake i tō mahunga ki ngā koki rerekē ka taea te whakanui ake i te whiwhinga i ētahi wā. Ko ngā pūihi waea pūkoro he mea porotaka te nuinga, nō reira ko te hurihuri i te waea ka taea te whakataurite i te porotaka o te waea, ā, ka pai ake te whiwhinga.
He āhuatanga e hiahiatia ana te porowhita porowhita o te nuinga o ngā pūihi. He porowhita te porowhita o ngā pūihi e rua, ā, kāore e pāngia e te ngaronga tohu nā te kore ōrite o te porowhita. Ko ngā pūihi e whakamahia ana i roto i ngā pūnaha GPS he porowhita te porowhita matau.
Inaianei, me kī ka whiwhi te pūihi porowhita porowhita i ngā ngaru porowhita porowhita. Waihoki, me kī ka ngana te pūihi porowhita porowhita ki te whiwhi i ngā ngaru porowhita porowhita. He aha te tauwehenga ngaronga porowhita e hua mai ana?
Kia maumahara ko te porowhita porowhita he rua ngā ngaru porowhita-rārangi, he 90 nekehanga te tawhiti. Nō reira, ko te pūihi porowhita-rārangi (LP) ka whiwhi noa i te wāhanga wāhanga ngaru porowhita-rārangi (CP). Nō reira, ko te ngaronga kore-rārangi o te pūihi LP he 0.5 (-3dB). He pono tēnei ahakoa te koki e hurihia ana te pūihi LP. Nō reira:
Ko te tauwehenga ngaronga pōraritanga e kiia ana i ētahi wā ko te pai o te pōraritanga, te tauwehenga kore taurite o te pūihi, te tauwehenga whiwhinga pūihi rānei. E pā ana ēnei ingoa katoa ki te ariā kotahi.
Wā tuku: Hakihea-22-2023
