Nā Laʻana Nīnau Kūkākūkā Microwave
ʻO nā microwave kahi ʻāpana o ka spectrum electromagnetic me nā nalu mai 1 mm a 1 m. Hoʻohana pinepine ʻia kēia mau nalu i nā ʻenehana hou like ʻole, e like me ke kamaʻilio uea ʻole, radar, astronomy, a me nā lako hale e like me nā umu microwave. Ma muli o ke koʻikoʻi o nā noi microwave, he mea nui ia no nā haumāna, ʻoiai ka poʻe e aʻo nui ana i ka physics a i ʻole ka ʻenekinia, e hoʻomaopopo i nā kumu o nā microwave, me ke ʻano o ka hoʻoponopono ʻana i nā pilikia e pili ana iā lākou. E kūkākūkā kēia ʻatikala i kekahi mau pilikia hoʻohālike a kūkākūkā i nā microwave.
Nīnau 1: Ka lōʻihi o ka nalu a me ka alapine (frequency)
Nīnau:
Hāʻawi ʻia he alapine (frequency) o ka microwave he 10 GHz, e helu i ka nalu o ka microwave. (E hoʻohana i ka wikiwiki o ka mālamalama c = 3 x 10^8 m/s)
Kūkākūkā:
ʻO ka mea mua, hoʻomanaʻo mākou i ka pilina ma waena o ka nalu (λ), ke alapine (f), a me ka wikiwiki o ke kukui (c):
\[ c = \lambda \cdot f \]
Hiki iā mākou ke hana hou i kēia ʻano hana e ʻike ai i ka nalu (λ):
\[ \lambda = \frac{c}{f} \]
Hāʻawi ʻia kahi alapine (f) = 10 GHz = 10 x 10^9 Hz, a me ka wikiwiki o ka mālamalama (c) = 3 x 10^8 m/s, hoʻokomo mākou i kēia mau waiwai ʻelua i loko o ke ʻano:
\[ \lambda = \frac{3 \times 10^8 \, \text{m/s}}{10 \times 10^9 \, \text{Hz}} \]
\[ \lambda = 0.03 \, \text{m} \]
No laila, ʻo ka nalu o ka microwave he 0,03 mika a i ʻole 3 kenimika.
Nīnau 2: Ka Hoʻoili ʻana i ka Mana a me ka Mamao
Nīnau:
Hoʻopuka kahi mea hoʻoili microwave i ka mana o 50 W. E helu i ka ikaika o ka microwave ma kahi mamao o 2 mika mai ke kumu mea hoʻoili, me ka manaʻo he isotropic propagation.
Kūkākūkā:
No ka helu ʻana i ka ikaika, hoʻohana mākou i ka hoohalike mana no kēlā me kēia ʻāpana wahi:
\[ I = \frac{P}{A} \]
ʻO P ka mana (50 W) a ʻo A ka ʻili o kahi poepoe me ka radius o 2 mika:
\[ A = 4 \pi r^2 \]
E hoʻokomo i ka waiwai r = 2 mika i loko o ke ʻano hana wahi:
\[ A = 4 \pi (2 \, \text{m})^2 \]
\[ A = 16 \pi \, \text{m}^2 \]
A laila e helu i ka ikaika:
\[ I = \frac{50 \, \text{W}}{16 \pi \, \text{m}^2} \]
Ke helu nei i nā waiwai helu:
\[ I \approx \frac{50}{50.265} \]
\[ I \approx 0.995 \, \text{W/m}^2 \]
No laila, ʻo ka ikaika o ka microwave ma kahi mamao o 2 mika mai ke kumu hoʻoili ma kahi o 0.995 W/m².
Nīnau 3: Ka hopena Doppler i loko o nā Microwaves
Nīnau:
Ke hoʻokokoke aku nei kahi kaʻa e neʻe ana ma 108 km/h (30 m/s) i kahi radar e hoʻouna ana i nā microwave ma ke alapine (frequency) o 5 GHz. E helu i ke alapine (frequency) i loaʻa i ka radar inā ʻo ka wikiwiki o ka microwave ka wikiwiki o ka mālamalama.
Kūkākūkā:
E hoʻohana i ka hopena Doppler no ke alapine i loaʻa (f'):
\[ f' = f \left(\frac{c + v}{c}\right) \]
Ma hea:
– f' = alapine i loaʻa
– f = alapine kumu = 5 GHz = 5 x 10^9 Hz
– c = ka wikiwiki o ka mālamalama = 3 x 10^8 m/s
– v = ka wikiwiki o ke kaʻa = 30 m/s
E hoʻololi i nā waiwai i loko o ke ʻano:
\[ f' = 5 \times 10^9 \left(\frac{3 \times 10^8 + 30}{3 \times 10^8}\right) \]
\[ f' \approx 5 \times 10^9 \left(1 + \frac{30}{3 \times 10^8}\right) \]
\[ f' \approx 5 \times 10^9 \left(1 + 1 \times 10^{-7}\right) \]
\[ f' \approx 5 \times 10^9 \times 1.0000001 \]
\[ f' \approx 5.0000005 \times 10^9 \]
\[ f' \approx 5.0000005 \, \text{GHz} \]
No laila, ʻo ke alapine (frequency) i loaʻa e ka radar ma kahi o 5.0000005 GHz.
Nīnau 4: Ka Hoʻopili Mana e nā Mea Hana
Nīnau:
Hoʻopili kekahi mea i 2 W o ka mana microwave ke 10 W/m² ka ikaika o ka nalu i komo mai. E helu i ka ʻili o ka mea.
Kūkākūkā:
E hoʻohana i ka pilina ma waena o ka mana omo a me ka ʻili a me ka ikaika:
\[ P = I \cdot A \]
E pani i nā waiwai i ʻike ʻia:
\[ 2 \, \text{W} = 10 \, \text{W/m}^2 \cdot A \]
Ke hoʻoponopono nei no A:
\[ A = \frac{2 \, \text{W}}{10 \, \text{W/m}^2} \]
\[ A = 0.2 \, \text{m}^2 \]
No laila, ʻo ka ʻili o ka mea he 0,2 m².
Nīnau 5: Nā ʻAno Hoʻohālikelike a me ke Kūʻē
Nīnau:
Hoʻopuka nā antenna microwave ʻelua i nā nalu o ka nalu he 6 cm ma ke kuhikuhi like. Inā he 12 cm ka mamao ma waena o nā antenna, i ka manawa hea e hana mua ʻia ai ka hoʻopilikia kūkulu?
Kūkākūkā:
Hana ʻia ka hoʻopilikia kūkulu i ka wā e like ai ka ʻokoʻa o ke ala ma waena o nā kumu ʻelua me k = ±nλ (he helu helu ʻole ʻo n me 0). No ka manawa mua, ʻo ka hoʻopilikia kūkulu (n=1):
\[ d = n \lambda/2 \]
ʻOiai ʻo ka mamao o ka antenna he 12 cm a ʻo ka nalu he 6 cm, ʻo ka ʻokoʻa o ke ala no ka hoʻopilikia kūkulu mua e hana ʻia ma:
\[ d = n (\lambda/2) \]
No laila:
\[ 12 = 1 \times (6/2) \]
No laila, ʻo ka mamao i loaʻa:
\[ 12 = 1 \times 3 \]
No ka mea, pili kēia kaulike i ka hoʻokumu ʻia ʻana o nā ʻano hoʻopilikia ma luna o ka mea maʻamau, a laila mai ke kuhi ʻana ua hoʻolālā mākou ma ka laina waena o ka mamao mai ke kumu a i ʻole ke ala e pili ana i ka non-track, ʻo ia hoʻi ke kūlana polar mau o ka laina trace i pili ʻole i ke ʻano kūlana paʻa i manaʻo ʻia.
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Eia kekahi mau laʻana o nā pilikia microwave a pehea e hoʻoponopono ai iā lākou. Ma ka hoʻomaopopo ʻana a me ka maʻa ʻana i ka hoʻoponopono ʻana i nā pilikia e like me kēia, ke manaʻolana nei e maʻalahi iā ʻoe ke hoʻomaopopo a hoʻopili i nā manaʻo microwave ma nā ʻano ʻepekema a me ka ʻenehana like ʻole.
