Mehlala ea Lipotso tsa Puisano ea Microwave
Maqhubu a microwave ke karolo ea sephara sa motlakase se nang le maqhubu a bolelele ba limithara tse 1 ho isa ho limithara tse 1. Maqhubu ana a sebelisoa khafetsa mahlaleng a fapaneng a sejoale-joale, joalo ka puisano ea waelese, radar, bolepi ba linaleli le lisebelisoa tsa ntlo joalo ka lionto tsa microwave. Ka lebaka la bohlokoa ba lits'ebetso tsa microwave, ho bohlokoa hore baithuti, haholo-holo ba ithutang fisiks kapa boenjiniere, ba utloisise metheo ea li-microwave, ho kenyeletsoa le mokhoa oa ho rarolla mathata a amanang le tsona. Sengoloa sena se tla tšohla mehlala e 'maloa ea mathata le ho tšohla li-microwave.
Potso ea 1: Bolelele ba maqhubu le maqhubu
Potso:
Kaha microwave e na le maqhubu a 10 GHz, bala bolelele ba leqhubu la microwave. (Sebelisa lebelo la khanya c = 3 x 10^8 m/s)
Puisano:
Sa pele, re hopola kamano pakeng tsa bolelele ba wavelength (λ), maqhubu (f), le lebelo la khanya (c):
\[ c = \lambda \cdot f \]
Re ka kgona kapa ra pheta foromo ena ho fumana bolelele ba wavelength (λ):
\[ \lambda = \frac{c}{f} \]
Ka lebaka la maqhubu (f) = 10 GHz = 10 x 10^9 Hz, le lebelo la khanya (c) = 3 x 10^8 m/s, re hokela boleng bona bo bobeli foromong:
\[ \lambda = \frac{3 \times 10^8 \, \text{m/s}}{10 \times 10^9 \, \text{Hz}} \]
\[ \lambda = 0.03 \, \mongolo{m} \]
Kahoo, bolelele ba maqhubu a microwave ke limithara tse 0,03 kapa 3 cm.
Potso ea 2: Matla a Fetisang le Sebaka
Potso:
Sesebediswa sa ho fetisa motlakase ka microwave se ntsha matla a 50 W. Bala matla a microwave bohole ba dimithara tse 2 ho tloha mohloding wa sesebediswa, o nahana ka ho ata ha isotropic.
Puisano:
Ho bala matla, re sebelisa equation ea sebaka sa matla ka yuniti:
\[ I = \frac{P}{A} \]
P ke matla (50 W) mme A ke sebaka sa bokaholimo ba selikalikoe se nang le radius ea limithara tse 2:
\[ A = 4 \pi r^2 \]
Kenya boleng ba r = limithara tse 2 foromong ea sebaka:
\[ A = 4 \pi (2 \, \text{m})^2 \]
\[ A = 16 \pi \, \text{m}^2 \]
Ebe o bala matla:
\[ I = \frac{50 \, \text{W}}{16 \pi \, \text{m}^2} \]
Ho bala boleng ba linomoro:
\[ I \hoo e ka bang \frac{50}{50.265} \]
\[ I \hoo e ka bang 0.995 \, \mongolo{W/m}^2 \]
Kahoo, matla a microwave bohōle ba limithara tse 2 ho tloha mohloling oa phetisetso ke hoo e ka bang 0.995 W/m².
Potso ea 3: Tšusumetso ea Doppler ho Maekrofono
Potso:
Koloi e tsamayang ka lebelo la 108 km/h (30 m/s) e atamela di-microwave tse fetisang radar ka lebelo la 5 GHz. Bala maqhubu a amohelwang ke radar haeba lebelo la microwave e le lebelo la lesedi.
Puisano:
Sebelisa phello ea Doppler bakeng sa maqhubu a amohetsoeng (f'):
\[ f' = f \left(\frac{c + v}{c}\right) \]
Di mana:
– f' = makhetlo a amohetsoeng
– f = maqhubu a mohloli = 5 GHz = 5 x 10^9 Hz
– c = lebelo la khanya = 3 x 10^8 m/s
– v = lebelo la koloi = 30 m/s
Kenya boleng ka mokhoa o latelang:
\[ f' = 5 \ka makhetlo a 10^9 \ka ho le letšehali(\frac{3 \ka makhetlo a 10^8 + 30}{3 \ka makhetlo a 10^8}\ka ho le letona) \]
\[ f' \hoo e ka bang 5 \ka makhetlo a 10^9 \ka ho le letšehali(1 + \ka ho le letona{30}{3 \ka makhetlo a 10^8}\ka ho le letona) \]
\[ f' \hoo e ka bang 5 \ka makhetlo a 10^9 \ka ho le letšehali(1 + 1 \ka makhetlo a 10^{-7}\ka ho le letona) \]
\[ f' \hoo e ka bang 5 \ka makhetlo a 10^9 \ka makhetlo a 1.0000001 \]
\[ f' \hoo e ka bang 5.0000005 \makgetlo a 10^9 \]
\[ f' \hoo e ka bang 5.0000005 \, \mongolo{GHz} \]
Kahoo, maqhubu a amoheloang ke radar ke hoo e ka bang 5.0000005 GHz.
Potso ea 4: Ho Monya Matla ka Lintho
Potso:
Thepa e itseng e monya matla a microwave a 2 W ha matla a leqhubu la ketsahalo e le 10 W/m². Bala sebaka sa bokaholimo ba thepa.
Puisano:
Sebelisa kamano pakeng tsa matla a ho monya le sebaka sa bokaholimo le matla:
\[ P = I \cdot A \]
Kenya mekhoa e tsebahalang sebakeng sa eona:
\[ 2 \, \mongolo{W} = 10 \, \mongolo{W/m}^2 \cdot A \]
Tharollo bakeng sa A:
\[ A = \frac{2 \, \text{W}}{10 \, \text{W/m}^2} \]
\[ A = 0.2 \, \mongolo{m}^2 \]
Kahoo, sebaka se ka holimo sa thepa ke 0,2 m².
Potso ea 5: Mekhoa ea ho Thuisa le ho Itšunya-tšunya
Potso:
Li-antenna tse peli tsa microwave li ntša maqhubu a bolelele ba 6 cm ka lehlakoreng le le leng. Haeba sebaka se pakeng tsa li-antenna e le 12 cm, tšitiso e hahang e qala ho etsahala neng?
Puisano:
Tšitiso e hahang e etsahala ha phapang ea tsela lipakeng tsa mehloli e 'meli e le k = ±nλ (n ke palo e se nang lefela ho kenyeletsoa 0). Ka lekhetlo la pele tšitiso e hahang (n=1):
\[d = n \lambda/2 \]
Kaha sebaka sa antenna ke 12 cm mme bolelele ba maqhubu ke 6 cm, phapang ea tsela bakeng sa tšitiso ea pele ea kaho e etsahala ho:
\[d = n (\lambda/2) \]
Kahoo:
\[ 12 = 1 \makgetlo (6/2) \]
Kahoo sebaka se fumanehang ke:
\[ 12 = 1 \makgetlo a 3 \]
Hobane equation ena e amana le ho thehwa ha dipaterone tsa tshitiso ho seo e leng kakaretso, ho tloha khopolo-tabang re rala moleng o bohareng wa sebaka ho tloha mohloding kapa tseleng ho itshetlehile hodima tsela e seng ya tsela, e leng boemo bo sa fetoheng ba polar ba moleng wa mohlala o sa amaneng le paterone ya boemo bo tsitsitseng bo nkuwang.
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Tsena ke mehlala e meng ea mathata a microwave le mokhoa oa ho a rarolla. Ka ho utloisisa le ho tloaela ho rarolla mathata a kang ana, ho tšeptjoa hore ho tla ba bonolo hore u utloisise le ho sebelisa likhopolo tsa microwave mafapheng a fapaneng a saense le theknoloji.
