huahelu 1
1. ʻO ke kukui kukui
ʻO kekahi mea maʻamau no ka loiloi ʻana i ka maikaʻi o ka hoʻouna ʻana a me ka loaʻa ʻana o nā antenna ʻo ia ka beam efficiency. No ka antenna me ka lobe nui ma ka z-axis kuhikuhi e like me ka mea i hoikeia ma ke Kii 1, ua hoakakaia ka beam efficiency (BE) penei:
ʻO ia ka ratio o ka mana i hoʻouna ʻia a i loaʻa paha i loko o ka huina cone θ1 i ka nui o ka mana i lawe ʻia a loaʻa paha e ka antenna. Hiki ke kākau ʻia ke ʻano o luna penei:
Inā koho ʻia ka huina i hōʻike ʻia ai ka helu mua a i ʻole ka waiwai liʻiliʻi e like me θ1, ʻo ka hoʻokō ʻana o ke kukui e hōʻike ana i ka ratio o ka mana ma ka lobe nui i ka mana holoʻokoʻa. I nā noi e like me ka metrology, astronomy, a me radar, pono e loaʻa i ka antenna kahi hana kiʻekiʻe loa. ʻOi aku ka maʻamau ma mua o 90%, a ʻo ka mana i loaʻa i ka lobe ʻaoʻao e liʻiliʻi e like me ka hiki.
2. Bandwidth
ʻO ka bandwidth o kahi antenna i wehewehe ʻia ʻo "ke alapine e hoʻokō ai ka hana o kekahi mau hiʻohiʻona o ka antenna i nā kūlana kikoʻī". Hiki ke noʻonoʻo ʻia ka bandwidth e like me ke alapine ma nā ʻaoʻao ʻelua o ke alapine waena (e pili ana i ke alapine resonant) kahi i loaʻa ai nā ʻano antenna (e like me ka impedance input, directional pattern, beamwidth, polarization, sidelobe level, gain, beam pointing, radiation. ʻoi aku ka maikaʻi) i loko o ka ʻae ʻia ma hope o ka hoʻohālikelike ʻana i ka waiwai o ke alapine waena.
. No nā antenna broadband, hōʻike pinepine ʻia ka bandwidth e like me ka ratio o nā alapine luna a me lalo no ka hana ʻae ʻia. No ka laʻana, ʻo ka bandwidth o 10:1 ʻo ia hoʻi ʻo ke alapine kiʻekiʻe he 10 mau manawa o ka alapine haʻahaʻa.
. No nā antenna narrowband, hōʻike ʻia ka bandwidth ma ke ʻano he pākēneka o ka ʻokoʻa alapine i ka waiwai waena. No ka la'ana, he 5% bandwidth 'o ia ho'i, 'o ia ka 5% o ka alapine e 'ae 'ia.
No ka mea, ʻokoʻa nā ʻano o ka antenna (input impedance, directional pattern, gain, polarization, etc.) me ke alapine, ʻaʻole kū hoʻokahi nā hiʻohiʻona bandwidth. ʻO ka maʻamau, ʻokoʻa nā loli i ke kumu kuhikuhi a me ka impedance hoʻokomo. No laila, pono ka bandwidth kuhikuhi a me ka bandwidth impedance e hoʻohālikelike i kēia ʻokoʻa. ʻO ka bandwidth pattern directional e pili ana i ka loaʻa, sidelobe pae, beamwidth, polarization a me ke kuhikuhi ʻana o ka beam, ʻoiai ʻo ka impedance komo a me ka pono radiation e pili ana i ka bandwidth impedance. Hōʻike pinepine ʻia ka bandwidth ma ke ʻano o ka beamwidth, sidelobe pae, a me nā hiʻohiʻona hiʻohiʻona.
Manaʻo ka kūkākūkā ma luna nei ʻaʻole e loli nā ana o ka pūnaewele hui (transformer, counterpoise, etc.) a / a i ʻole antenna i kekahi ʻano e like me ka loli ʻana o ke alapine. Inā hiki ke hoʻoponopono pono ʻia nā ana koʻikoʻi o ka antenna a me / a i ʻole ka hui hui ʻana e like me ka hoʻololi ʻana o ke alapine, hiki ke hoʻonui ʻia ka bandwidth o kahi antenna narrowband. ʻOiai ʻaʻole ia he hana maʻalahi ma ka laulā, aia nā noi kahi e hiki ai ke hoʻokō. ʻO ka laʻana maʻamau ka antenna lekiō i loko o kahi lekiō kaʻa, kahi maʻamau i hiki ke hoʻololi ʻia ka lōʻihi hiki ke hoʻohana ʻia e hoʻokani i ka antenna no ka hoʻokipa maikaʻi ʻana.
No ka ʻike hou aku e pili ana i nā antenna, e kipa:
Ka manawa hoʻouna: Jul-12-2024
