ʻO ka bandwidth kekahi ʻano antenna kumu. Hōʻike ka bandwidth i ka laulā o nā alapine (frequencies) e hiki ai i ka antenna ke hoʻolaha pololei a loaʻa paha ka ikehu. ʻO ka maʻamau, ʻo ka bandwidth i koi ʻia kekahi o nā ʻano i hoʻohana ʻia e koho i ke ʻano antenna. No ka laʻana, he nui nā ʻano antenna me nā bandwidths liʻiliʻi loa. ʻAʻole hiki ke hoʻohana ʻia kēia mau antenna i nā noi broadband.
ʻO ka maʻamau, ua ʻōlelo ʻia ka bandwidth ma ke ʻano o ka lakio nalu kū voltage (VSWR). No ka laʻana, hiki ke wehewehe ʻia kahi antenna he VSWR <1.5 ma luna o 100-400 MHz. Ua ʻōlelo ka ʻōlelo he emi ka coefficient reflection ma mua o 0.2 ma waena o ka laulā alapine i ʻōlelo ʻia. No laila, o ka mana i hāʻawi ʻia i ka antenna, ʻo 4% wale nō o ka mana i hōʻike ʻia i ka transmitter. Eia kekahi, ʻo ka pohō hoʻihoʻi S11 =20* LOG10 (0.2) = 13.98 decibels.
E ʻoluʻolu e hoʻomaopopo ʻaʻole manaʻo ka mea i luna nei ua hāʻawi ʻia ka 96% o ka mana i ka antenna ma ke ʻano o ka radiation electromagnetic i hoʻolaha ʻia. Pono e noʻonoʻo ʻia ka pohō mana.
Eia kekahi, e loli ke ʻano o ka radiation me ka alapine (frequency). Ma keʻano laulā, ʻaʻole e hoʻololi nui ke ʻano o ke ʻano radiation i ke alapine (frequency).
Aia paha kekahi mau kūlana ʻē aʻe i hoʻohana ʻia e wehewehe i ka bandwidth. Hiki i kēia ke polarizing i loko o kahi laulā. No ka laʻana, hiki ke wehewehe ʻia kahi antenna polarized circular me ka ratio axial o <3 dB mai 1.4-1.6 GHz (emi ma mua o 3 dB). ʻO kēia laulā hoʻonohonoho bandwidth polarization ma kahi o nā antenna polarized circular.
Hoʻākāka pinepine ʻia ka bandwidth i loko o kāna Fractional Bandwidth (FBW). ʻO FBW ka lakio o ka laulā alapine i puʻunaue ʻia e ke alapine waena (alapine kiʻekiʻe loa me ka alapine haʻahaʻa loa). Pili pū ka "Q" o kahi antenna i ka bandwidth (ʻo ke kiʻekiʻe o Q ke ʻano o ka bandwidth haʻahaʻa a me ka vice versa).
No ka hāʻawi ʻana i kekahi mau laʻana paʻa o ka bandwidth, eia kahi papa o nā bandwidth no nā ʻano antenna maʻamau. E pane kēia i nā nīnau, "He aha ka bandwidth o kahi antenna dipole?" a "ʻO wai ka antenna i loaʻa ka bandwidth kiʻekiʻe - he patch a he antenna helix paha?". No ka hoʻohālikelike ʻana, loaʻa iā mākou nā antenna me kahi alapine waena o 1 GHz (gigahertz) kēlā me kēia.
Nā bandwidth o kekahi mau antennas maʻamau.
E like me kāu e ʻike ai mai ka papa ʻaina, hiki ke ʻokoʻa loa ka bandwidth o ka antenna. He haʻahaʻa loa ka bandwidth o nā antenna Patch (microstrip), ʻoiai he nui loa ka bandwidth o nā antenna helical.
Ka manawa hoʻouna: Nov-24-2023
