1. He aha ka Antenna?
E like me kā kākou ʻike, aia nā ʻano wnā mea kamaʻilio irelessi ko mākou ola, e like me ka drone wikiō downlink,loulou uila no ka lopako, ʻōnaehana mesh kikohoʻea ke hoʻohana nei kēia ʻōnaehana hoʻolele lekiō i nā nalu lekiō e hoʻouna i nā ʻike e like me ke wikiō, leo a me ka ʻikepili.ʻO ka antenna kahi mea i hoʻohana ʻia no ka hoʻomālamalama ʻana a me ka loaʻa ʻana o nā hawewe lekiō.
2.Antenna bandwidth
Ke hoʻololi ke alapine hana o ka antenna, ʻo ka degere o ka hoʻololi ʻana o nā ʻāpana uila pili o ka antenna aia i loko o ka pae i ʻae ʻia.ʻO ka laulā alapine hiki ke ʻae ʻia i kēia manawa ʻo ka antenna frequency band width, ka mea maʻamau i kapa ʻia he bandwidth.Loaʻa i kēlā me kēia antenna kahi bandwidth hana, a ʻaʻohe hopena kūpono ma waho o kēia band frequency.
Ka bandwidth piha: ABW=fmax - fmin
Ka bandwidth pili: FBW=(fmax - fmin)/f0×100%
f0=1/2(fmax + fmin) ʻo ia ke alapine waena
Ke hana ka antenna ma ke alapine waena, ʻo ka lākiō hawewe kū ka mea liʻiliʻi loa a ʻo ka pono ke kiʻekiʻe loa.
No laila, hōʻike pinepine ʻia ke ʻano o ka bandwidth pili penei: FBW=2(fmax-fmin)/(fmax+ fmin)
No ka mea, ʻo ka bandwidth antenna ka laina alapine hana kahi e hoʻokō ai kekahi a i ʻole kekahi o nā ʻāpana hana uila o ka antenna i nā koi, hiki ke hoʻohana ʻia nā ʻāpana uila like ʻole e ana i ka laulā o ka band frequency.No ka laʻana, ʻo ka laulā alapine e pili ana i ka laula lobe 3dB (ʻo ka laula lobe e pili ana i ke kihi ma waena o ʻelua mau kiko kahi i emi ai ka ikaika o ka radiation e 3dB, ʻo ia hoʻi, e emi ana ka mana o ka mana ma ka hapalua, ma nā ʻaoʻao ʻelua o ke kuhikuhi radiation kiʻekiʻe. o ka lobe nui), a me ka laulā alapine (frequency band width) kahi e kū ai ka lākiō hawewe kū i kekahi mau koi.I waena o lākou, ʻo ka mea maʻamau i hoʻohana ʻia ʻo ia ka bandwidth i ana ʻia e ka lākiō hawewe kū.
3. ʻO ka pilina ma waena o ka hana pinepine a me ka nui antenna
Ma ke ala like, ʻike maopopo ka wikiwiki o ka hoʻolaha ʻana o nā hawewe electromagnetic (e like me ka wikiwiki o ka mālamalama i loko o kahi ʻōpala, i hoʻopaʻa ʻia c≈3×108m/s).Wahi a c=λf, hiki ke ʻike ʻia he ʻano like ʻole ka lōʻihi o ka nalu me ke alapine, a ʻo nā mea ʻelua wale nō ka pilina pili.
ʻO ka lōʻihi o ka antenna e pili pono i ka nalu a me ka hoʻohālikelike ʻana i ke alapine.ʻO ia hoʻi, ʻoi aku ka kiʻekiʻe o ke alapine, ʻoi aku ka pōkole o ka nalu, a me ka pōkole o ka antenna hiki ke hana.ʻOiaʻiʻo, ʻaʻole like ka lōʻihi o ka antenna i hoʻokahi nalu nalu, akā ʻo ka 1/4 ka lōʻihi o ka hawewe a i ʻole 1/2 ka lōʻihi o ka hawewe (ʻo ka nui o ka nalu e pili ana i ke alapine hana waena).No ka mea, ke lilo ka lōʻihi o ka mea hoʻokele i ka helu helu o ka hawewe 1/4, hōʻike ka mea lawe i nā ʻano resonance ma ke alapine o kēlā nalu.Inā he 1/4 ka lōʻihi o ka hawewe, loaʻa iā ia nā hiʻohiʻona resonance, a ʻo ka lōʻihi o ka conductor he 1/2 ka lōʻihi o ka nalu, aia nā ʻano resonance like.Ma kēia kūlana resonance, e hoʻomālamalama ikaika ka antenna a ʻoi aku ka kiʻekiʻe o ka hoʻololi ʻana a me ka hoʻokipa ʻana.ʻOiai ʻoi aku ka nui o ka radiation o ka oscillator ma mua o 1/2 o ka lōʻihi o ka nalu, e hoʻomau ʻia ka hoʻonui ʻia ʻana o ka radiation, akā ʻo ka radiation anti-phase o ka hapa nui e hoʻopuka i kahi hopena hoʻopau, no laila ua hoʻohālikelike ʻia ka hopena radiation holoʻokoʻa.No laila, hoʻohana nā antenna maʻamau i ka ʻāpana oscillator lōʻihi o ka hawewe 1/4 a i ʻole ka lōʻihi hawewe 1/2.Ma waena o lākou, hoʻohana nui ka antenna 1/4-wavelength i ka honua ma ke aniani ma kahi o ka antenna hapalua hawewe.
Hiki i ka antenna hawewe 1/4 ke hoʻokō i ka lākiō hawewe kū kūpono a me ka hopena hoʻohana ma o ka hoʻoponopono ʻana i ke ʻano, a i ka manawa like, hiki iā ia ke mālama i ka wahi hoʻonohonoho.Eia nō naʻe, ʻo nā antenna o kēia lōʻihi he haʻahaʻa haʻahaʻa a ʻaʻole hiki ke hoʻokō i nā pono o kekahi mau hiʻohiʻona hoʻoili kiʻekiʻe.I kēia hihia, hoʻohana mau ʻia nā antenna 1/2-lōʻihi hawewe.
Eia kekahi, ua hōʻoia ʻia ma ke kumumanaʻo a me ka hoʻomaʻamaʻa ʻana ʻo ka 5/8 wavelength array (ua kokoke kēia lōʻihi i ka 1/2 wavelength akā ʻoi aku ka ikaika o ka radiation ma mua o ka 1/2 wavelength) a i ʻole ka 5/8 wavelength loading shortening array (aia aia. hiki ke hoʻolālā ʻia a koho ʻia paha e kiʻi i kahi antenna loaʻa i ke kumu kūʻai a ʻoi aku ka kiʻekiʻe.
Hiki ke ʻike ʻia i ka wā e ʻike ai mākou i ke alapine hana o ka antenna, hiki iā mākou ke helu i ka lōʻihi o ka nalu, a laila hui pū ʻia me ka manaʻo laina laina, nā kūlana hoʻonohonoho hoʻonohonoho a me nā koi loaʻa lawe, hiki iā mākou ke ʻike i ka lōʻihi kūpono o ka antenna i koi ʻia. .
Ka manawa hoʻouna: ʻOkakopa-13-2023
