matua

Ariā Pūihi – Ngā Tawhā Taketake

Ka whakaurua e tēnei upoko ngā tawhā matua o te whakawhitiwhiti kōrero ahokore, e whai ana kia pai ake te māramatanga ki te tūranga o ngā pūihi i roto i ngā pūnaha whakawhitiwhiti kōrero. Ka whakahaerehia te whakawhitiwhiti kōrero ahokore i roto i te āhua o ngā ngaru hikohiko, nō reira he mea nui kia mārama ki ngā āhuatanga horapa o ngā ngaru.

I roto i tēnei upoko, ka matapakihia e mātou ngā tawhā e whai ake nei:

• Auautanga
•Roanga ngaru
•Te Whakataurite Āraitanga
•VSWR me te Mana Whakaata
•Whānuitanga o te arai
•Te Whānuitanga o te Ōrau
•Te Kaha o te Irahiko

Nā, kia tirohia tātou i ēnei āhuatanga.

Auautanga:

E ai ki te whakamāramatanga paerewa, ko te auautanga te maha o ngā whakahokinga o tētahi ngaru mō ia wā. I roto i ngā kupu māmā, e whakaahua ana te auautanga i te auau o te puta o tētahi huihuinga. Ka whakahokinga te ngaru ā-wā i ia T hēkona (kotahi wā), ā, ko tōna auautanga he taurite o te wā T.

Ina tirohia te pāngarau, penei te āhua:

$$f = \frac{1}{T}$$

•E tohu ana a F i te auau o te ngaru ā-wā, ko

•Ko T te wā e hiahiatia ana hei whakaoti i tētahi huringa katoa.

Ka inehia te auau i roto i te hertz, e whakarapopototia ana ko Hz.

ngaohiko

E whakaatu ana te ahua i runga ake nei i tētahi ngaru sine, e whakaatu ana i te ngaohiko (i roto i te mV) hei pānga o te wā (i roto i te ms). Ka tāruarua tēnei āhua ngaru i ia 2t mirihekona; nō reira, ko tōna wā T = 2t ms, me tōna auau f = 1/(2t) kHz.

Roangaru:

E ai ki te whakamāramatanga paerewa, ko te tawhiti i waenganui i ngā tihi e rua karapīpiti, i ngā awaawa e rua karapīpiti rānei ka kiia ko te roanga ngaru.

Ki te kī māmā noa, ko te roanga ngaru te tawhiti i waenganui i ngā tihi pai e rua e tata ana, i ngā tihi kino e rua rānei e tata ana. E whakaatu ana te pikitia i raro nei i tētahi āhua ngaru ā-wā, me te roanga ngaru (λ) me te kaha kua tohua. Ko te teitei ake o te auau, ko te poto ake o te roanga ngaru, ā, ko te ritenga kē.

whānui

Ko te tātai mō te roanga ngaru ko:

$$\lambda = \frac{c}{f}$$

•E tohu ana a λ i te roanga ngaru

•Ko C te tere o te mārama ($3 \x 10^8$ mita ia hekona)

•Ko F te auau

Ko te roangaru λ e whakaatuhia ana i roto i ngā waeine roa, pērā i te mita, te putu, te inihi rānei. Ko te waeine e whakamahia whānuitia ana ko te mita.

Te Whakataurite Āraitanga:

E ai ki te whakamāramatanga paerewa, ka puta te taurite aukati ina tata rite te aukati o te tuku ki te aukati o te kaiwhiwhi.

Me taurite te ātete i waenga i te pūihi me te ara iahiko. Me taurite ngā ātete o te pūihi, te raina tuku, me te ara iahiko kia eke ai te whakawhiti mana mōrahi i waenga i te pūihi me te kaiwhiwhi, te tuku rānei.

Te Hiahia o te Taurite
Ka taea e ngā taputapu orooro te tuku putanga tino pai i roto i ētahi auau whāiti. Hei taputapu orooro, ka taea e te pūihi te whakatutuki i te mahi putanga pai ake ina taurite tika tōna aukati.

•Ina ōrite te aukati o te pūihi ki te aukati o te wāhi wātea, ka tukuna pai te mana e tukuna ana e te pūihi

•Mō te pūihi whiwhi, me ōrite tōna aukati putanga ki te aukati tāuru o te ara iahiko whakakaha whiwhi

•Mō te pūihi tuku, me ōrite tōna ārai whakauru ki te ārai putanga o te whakakaha tuku me te ārai āhuatanga o te raina tuku

Ka inehia te parenga i roto i ngā ohms, e tohuhia ana e te tohu Z.

VSWR me te Mana Whakaata:

E ai ki te whakamāramatanga paerewa, ko te ōwehenga o te ngaohiko mōrahi ki te ngaohiko iti rawa i roto i te ngaru tū ka kiia ko te ōwehenga ngaru tū ngaohiko (VSWR).

Ina kore e ōrite ngā ārai o te pūihi, te raina tuku, me te ara iahiko, kāore e taea te tuku tika i te hiko; engari, ka whakaatahia anō tetahi wāhanga o te hiko.

Ko ngā āhuatanga matua ko —

•Ko te tawhā e tohu ana i te nui o te kore taurite o te aukati ka kiia ko te Tauwehenga Ngaru Tū Ngaohiko (VSWR)

•Ko te VSWR he whakarāpopototanga mō te Voltage Standing Wave Ratio, ā, e mōhiotia whānuitia ana ko te SWR

•Ka nui ake te kore taurite o te aukati, ka teitei ake te uara VSWR

•Hei whakatutuki i te irahiko whai hua, ko te uara VSWR tino pai ko te 1:1

•Ko te mana whakaata e pā ana ki te wāhanga o te mana whakamua e maumauria ana. Ko te mana whakaata me te VSWR e whakaahua ana i te āhuatanga ā-tinana kotahi mai i ngā tirohanga rerekē.

Whānuitanga o te ara:

E ai ki te whakamāramatanga paerewa, ko te roopu auau i roto i tētahi awhe roangaru kua tohua kua tohaina mō tētahi whakawhitiwhiti kōrero ka kiia ko te whānui o te hononga.

Ina tukuna, ina whiwhi rānei i tētahi tohu, ka mahi i roto i tētahi awhe auau kua whakaritea. Ka tohaina tēnei awhe auau motuhake ki tētahi tohu motuhake hei ārai i te pokanoa mai i ētahi atu tohu i te wā e tukuna ana.

•Ko te whānui o te ara iahiko e pā ana ki te awhe auau i waenga i ngā rohe auau-tiketike me ngā rohe auau-iti o te tuku tohu

•Kia tohaina te whānui o te rohe, kāore e taea te whakamahi e ētahi atu

•Kua wehea te whānuitanga katoa ki ngā wāhanga whānui, ia wāhanga kua tohaina ki ngā tuku rerekē

Ka taea hoki te kī ko te whānui o te whānuitanga kua kōrerotia ake nei ko te whānui o te whānuitanga tuturu.

Ōrautanga o te Whānuitanga

E ai ki te whakamāramatanga paerewa, ko te ōwehenga o te whānui whānui tino ki tōna auau pokapū ka kiia ko te ōrau whānui whānui.

Ko te auau i roto i tētahi roopu e eke ai te kaha o te tohu ki tōna taumata teitei ka kiia ko te auau whakakorikori, e mōhiotia ana hoki ko te auau pokapū o te roopu, e tohuhia ana ko fC.

•Ko ngā auau teitei ake me ngā auau iti iho o te roopu ka tohua ko fH me fL, ia

•Ko te whānui whānui tuturu e hoatu ana e fH − fL

•Hei aromatawai i te whānui o te roopu auau, me tatau te whānuitanga haurua, te whānuitanga ōrau rānei

Ka tatauhia te ōrau o te whānui o te raraunga kia mārama ai ki te whānuitanga o ngā rerekētanga auau ka taea e tētahi wāhanga, e tētahi pūnaha rānei te whakahaere.

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•fH​ e tohu ana i te auau teitei ake

•fL​ e tohu ana i te auau iti iho

•fc​ e tohu ana i te auau pokapū

Ko te nui ake o te ōrau o te whānui o te hongere, ko te whānui ake o te whānui o te hongere.

Te Kaha o te Irahiko:

Ko te kaha o te irahiko e tautuhia ana ko te mana e irahikohia ana mō ia wae koki totoka.

Ka kaha ake te whiti o te pūihi ki ētahi ahunga, e rite ana ki tōna kaha mōrahi o te hihi. Ko te whānuitanga mōrahi o te hihi ka tohuhia e te kaha o te hihi.

Te Whakapuakitanga Pāngarau
Ka whiwhihia te kaha o te irahiko mā te whakarea i te kiato mana irahiko mā te tapawhā o te tawhiti irahiko:

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Ko U te kaha o te irahiko, ko r te tawhiti radial, ā, ko (Wrad)​ te mātotoru mana irahiko.

•E tohu ana a U i te kaha o te irahiko

•e tohu ana a r i te tawhiti porowhita

•E tohu ana a Wrad i te mātotoru mana irahiko

E whakaatu ana te whārite i runga ake nei i te kaha o te irahiko o te pūihi. Ko te tawhiti irahiko i ētahi wā ka tohua ki te tohu Φ.

Ko te waeine o te kaha o te irahiko ko te watts ia steradian (W/sr), ko te watts rānei ia radian tapawhā (W/rad²).

Mō ētahi atu kōrero mō ngā antenna, tirohia:


Wā tuku: Maehe-26-2026

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