Nūhou - He Loiloi o nā Antenna Laina Hoʻoili Metamaterial

I. Hoʻolauna
Hiki ke wehewehe maikaʻi ʻia nā Metamaterials ma ke ʻano he mau ʻano hana i hoʻolālā ʻia e hana i kekahi mau waiwai electromagnetic i kū ʻole ma ke ʻano maoli. ʻO nā Metamaterials me ka permittivity maikaʻi ʻole a me ka permeability maikaʻi ʻole ua kapa ʻia he mau metamaterials lima hema (LHMs). Ua aʻo nui ʻia nā LHMs ma nā kaiāulu ʻepekema a me nā ʻenekinia. I ka makahiki 2003, ua kapa ʻia ʻo LHMs kekahi o nā holomua ʻepekema he ʻumi kiʻekiʻe o kēia au e ka makasina Science. Ua hoʻomohala ʻia nā noi hou, nā manaʻo, a me nā mea hana ma ka hoʻohana ʻana i nā waiwai kūikawā o LHMs. ʻO ke ʻano o ka laina hoʻoili (TL) kahi ʻano hoʻolālā kūpono e hiki ai ke kālailai i nā kumumanaʻo o LHMs. Ke hoʻohālikelike ʻia me nā TL kuʻuna, ʻo ka hiʻohiʻona koʻikoʻi o nā metamaterial TL ka hiki ke hoʻokele i nā palena TL (propagation constant) a me ka impedance ʻano. Hāʻawi ka hiki ke hoʻokele i nā palena TL metamaterial i nā manaʻo hou no ka hoʻolālā ʻana i nā ʻano antenna me ka nui compact, ka hana kiʻekiʻe, a me nā hana hou. Hōʻike ka Kiʻi 1 (a), (b), a me (c) i nā hiʻohiʻona kaapuni nalowale ʻole o ka laina hoʻoili lima ʻākau maʻemaʻe (PRH), ka laina hoʻoili lima hema maʻemaʻe (PLH), a me ka laina hoʻoili lima hema-ʻākau i hui pū ʻia (CRLH). E like me ka mea i hōʻike ʻia ma ke Kiʻi 1(a), ʻo ke kumu hoʻohālike kaapuni like PRH TL he hui pū ʻana o ka inductance series a me ka capacitance shunt. E like me ka mea i hōʻike ʻia ma ke Kiʻi 1(b), ʻo ke kumu hoʻohālike kaapuni PLH TL he hui pū ʻana o ka inductance shunt a me ka capacitance series. I nā noi hana, ʻaʻole hiki ke hoʻokō i kahi kaapuni PLH. ʻO kēia ma muli o ka hopena inductance series parasitic a me ka capacitance shunt hiki ʻole ke pale ʻia. No laila, ʻo nā ʻano o ka laina hoʻoili lima hema i hiki ke hoʻomaopopo ʻia i kēia manawa he mau ʻano hana lima hema a me ka lima ʻākau i hui pū ʻia, e like me ka mea i hōʻike ʻia ma ke Kiʻi 1(c).

Kiʻi 1 Nā ʻano hoʻohālike kaapuni laina hoʻoili like ʻole

Ua helu ʻia ke kūpaʻa hoʻolaha (γ) o ka laina hoʻoili (TL) penei: γ=α+jβ=Sqrt(ZY), kahi e hōʻike ai ʻo Y a me Z i ka admittance a me ka impedance. Ke noʻonoʻo nei iā CRLH-TL, hiki ke hōʻike ʻia ʻo Z a me Y penei:

E loaʻa i kahi CRLH TL like ka pilina hoʻopuehu penei:

Hiki i ke kūpaʻa pae β ke lilo i helu maoli maoli a i ʻole he helu hoʻokalakupua maoli. Inā he maoli loa ʻo β i loko o kahi alapine (frequency), aia kahi passband i loko o ka alapine ma muli o ke kūlana γ=jβ. Ma ka ʻaoʻao ʻē aʻe, inā he helu hoʻokalakupua maoli ʻo β i loko o kahi alapine, aia kahi stopband i loko o ka alapine ma muli o ke kūlana γ=α. He kū hoʻokahi kēia stopband iā CRLH-TL a ʻaʻole ia ma PRH-TL a i ʻole PLH-TL. Hōʻike nā Kiʻi 2 (a), (b), a me (c) i nā piʻo hoʻopuehu (ʻo ia hoʻi, ka pilina ω - β) o PRH-TL, PLH-TL, a me CRLH-TL. Ma muli o nā piʻo hoʻopuehu, hiki ke loaʻa a kuhi ʻia ka wikiwiki o ka hui (vg=∂ω/∂β) a me ka wikiwiki pae (vp=ω/β) o ka laina hoʻoili. No PRH-TL, hiki ke hoʻomaopopo ʻia mai ka piʻo he like ʻo vg a me vp (ʻo ia hoʻi, vpvg>0). No PLH-TL, hōʻike ka piʻo ʻaʻole like ʻo vg a me vp (ʻo ia hoʻi, vpvg<0). Hōʻike pū ka piʻo hoʻopuehu o CRLH-TL i ke ola ʻana o ka ʻāpana LH (ʻo ia hoʻi, vpvg < 0) a me ka ʻāpana RH (ʻo ia hoʻi, vpvg > 0). E like me ka mea i ʻike ʻia mai ke Kiʻi 2(c), no CRLH-TL, inā he helu maoli maʻemaʻe ʻo γ, aia kahi hui kū.

Kiʻi 2 Nā piʻo hoʻopuehu o nā laina hoʻoili like ʻole

ʻO ka maʻamau, ʻokoʻa nā resonances moʻo a me nā parallel o kahi CRLH-TL, kahi i kapa ʻia he kūlana kaulike ʻole. Eia nō naʻe, i ka wā like ai nā alapine resonance moʻo a me nā parallel, ua kapa ʻia ʻo ia he kūlana kaulike, a ua hōʻike ʻia ke kumu hoʻohālike kaapuni like maʻalahi ma ka Kiʻi 3(a).

Kiʻi 3 Kumu hoʻohālike kaapuni a me ke piʻo hoʻopuehu o ka laina hoʻoili lima hema i hui pū ʻia

I ka piʻi ʻana o ke alapine (frequency), piʻi mālie nā ʻano hoʻopuehu o CRLH-TL. ʻO kēia no ka mea, ʻo ka wikiwiki o ka pae (ʻo ia hoʻi, vp=ω/β) e hilinaʻi nui ʻia ana i ke alapine (frequency). Ma nā alapine haʻahaʻa, ua noho aliʻi ʻia ʻo CRLH-TL e LH, ʻoiai ma nā alapine kiʻekiʻe, ua noho aliʻi ʻia ʻo CRLH-TL e RH. Hōʻike kēia i ke ʻano pālua o CRLH-TL. Hōʻike ʻia ke kiʻikuhi hoʻopuehu kaulike CRLH-TL ma ke Kiʻi 3(b). E like me ka mea i hōʻike ʻia ma ke Kiʻi 3(b), ʻo ka hoʻololi ʻana mai LH a i RH e hana ʻia ma:

Ma kahi ʻo ω0 ke alapine hoʻololi. No laila, i ke kūlana kaulike, hana ʻia kahi hoʻololi mālie mai LH a i RH no ka mea he helu hoʻokalakupua wale nō ʻo γ. No laila, ʻaʻohe wahi kū no ka hoʻolaha kaulike ʻana o CRLH-TL. ʻOiai ʻo β he ʻole ma ω0 (palena ʻole e pili ana i ka nalu alakaʻi, ʻo ia hoʻi, λg=2π/|β|), hoʻolaha mau ka nalu no ka mea ʻaʻole ʻo vg ma ω0 he ʻole. Pēlā nō, ma ω0, ʻo ka neʻe ʻana o ka pae he ʻole no kahi TL o ka lōʻihi d (ʻo ia hoʻi, φ= - βd=0). ʻO ka holomua pae (ʻo ia hoʻi, φ>0) e hana ʻia ma ka pae alapine LH (ʻo ia hoʻi, ω<ω0), a ʻo ka lohi pae (ʻo ia hoʻi, φ<0) e hana ʻia ma ka pae alapine RH (ʻo ia hoʻi, ω>ω0). No kahi CRLH TL, ua wehewehe ʻia ka impedance ʻano penei:

Ma kahi o ZL a me ZR nā impedances PLH a me PRH, kēlā me kēia. No ka hihia kaulike ʻole, pili ka impedance hiʻohiʻona i ke alapine (frequency). Hōʻike ka hoohalike ma luna nei ua kūʻokoʻa ka hihia kaulike mai ke alapine (frequency), no laila hiki iā ia ke loaʻa kahi kūlike bandwidth ākea. Ua like ka hoohalike TL i loaʻa ma luna me nā palena constitutive e wehewehe ana i ka mea CRLH. ʻO ke kūpaʻa hoʻolaha o TL ʻo γ=jβ=Sqrt(ZY). Hāʻawi ʻia i ke kūpaʻa hoʻolaha o ka mea (β=ω x Sqrt(εμ)), hiki ke loaʻa ka hoohalike ma lalo nei:

Pēlā nō, ʻo ke ʻano o ka impedance o TL, ʻo ia hoʻi, Z0=Sqrt(ZY), ua like ia me ke ʻano o ka impedance o ka mea, ʻo ia hoʻi, η=Sqrt(μ/ε), i hōʻike ʻia penei:

Ua hōʻike ʻia ka helu kuhi o ka CRLH-TL kaulike a kaulike ʻole (ʻo ia hoʻi, n = cβ/ω) ma ke Kiʻi 4. Ma ke Kiʻi 4, he maikaʻi ʻole ka helu kuhi o ka CRLH-TL ma kona pae LH a he maikaʻi ka helu kuhi o ka CRLH-TL ma kona pae RH.

Kiʻi 4 Nā ʻōkuhi refractive maʻamau o nā CRLH TL kaulike a kaulike ʻole.

1. Pūnaewele LC
Ma ka hoʻopili ʻana i nā pūnaewele LC bandpass i hōʻike ʻia ma ke Kiʻi 5(a), hiki ke kūkulu ʻia kahi CRLH-TL maʻamau me ke ʻano like o ka lōʻihi d i kēlā me kēia manawa a i ʻole ʻaʻole i kēlā me kēia manawa. Ma keʻano laulā, i mea e hōʻoia ai i ka maʻalahi o ka helu ʻana a me ka hana ʻana o CRLH-TL, pono ke kaapuni e hana i kēlā me kēia manawa. Ke hoʻohālikelike ʻia me ke kumu hoʻohālike o ke Kiʻi 1(c), ʻaʻohe nui o ke kelepona kaapuni o ke Kiʻi 5(a) a he liʻiliʻi loa ka lōʻihi kino (ʻo ia hoʻi, Δz i nā mika). Ke noʻonoʻo nei i kona lōʻihi uila θ=Δφ (rad), hiki ke hōʻike ʻia ke ʻano o ke kelepona LC. Eia naʻe, i mea e ʻike maoli ai i ka inductance a me ka capacitance i hoʻopili ʻia, pono e hoʻokumu ʻia kahi lōʻihi kino p. ʻO ke koho ʻana o ka ʻenehana noi (e like me ka microstrip, coplanar waveguide, nā ʻāpana hoʻopaʻa ʻili, a me nā mea ʻē aʻe) e hoʻopilikia i ka nui kino o ke kelepona LC. Ua like ke kelepona LC o ke Kiʻi 5(a) me ke kumu hoʻohālike hoʻonui o ke Kiʻi 1(c), a ʻo kona palena p=Δz→0. Wahi a ke kūlana like p→0 ma ke Kiʻi 5(b), hiki ke kūkulu ʻia kahi TL (ma o ka hoʻopili ʻana i nā pūnaewele LC) e like me kahi CRLH-TL like kūpono me ka lōʻihi d, i ʻike ʻia ai ka TL e like me nā nalu electromagnetic.

Kiʻi 5 CRLH TL ma muli o ka pūnaewele LC.

No ke kelepona LC, e noʻonoʻo ana i nā kūlana palena manawa (PBC) e like me ka theorem Bloch-Floquet, ua hōʻoia ʻia ka pilina hoʻopuehu o ke kelepona LC a ua hōʻike ʻia penei:

Ua hoʻoholo ʻia ka impedance series (Z) a me ka shunt admittance (Y) o ke kelepona LC e nā kaulike aʻe:

ʻOiai he liʻiliʻi loa ka lōʻihi uila o ke kaapuni LC unit, hiki ke hoʻohana ʻia ka hoʻokokoke ʻana o Taylor e loaʻa ai:

2. Hoʻokō Kino
Ma ka ʻāpana i hala, ua kūkākūkā ʻia ka pūnaewele LC e hana iā CRLH-TL. Hiki ke hoʻokō ʻia kēlā mau pūnaewele LC ma o ka hoʻohana ʻana i nā ʻāpana kino e hiki ke hana i ka capacitance i koi ʻia (CR a me CL) a me ka inductance (LR a me LL). I nā makahiki i hala iho nei, ua huki nui ʻia ka hoihoi i ka hoʻohana ʻana i nā ʻāpana chip ʻenehana hoʻopaʻa ʻili (SMT) a i ʻole nā ʻāpana i hoʻolaha ʻia. Hiki ke hoʻohana ʻia ka Microstrip, stripline, coplanar waveguide a i ʻole nā ʻenehana like ʻē aʻe e hoʻokō i nā ʻāpana i hoʻolaha ʻia. Nui nā mea e noʻonoʻo ai i ke koho ʻana i nā chips SMT a i ʻole nā ʻāpana i hoʻolaha ʻia. ʻOi aku ka maʻamau a me ka maʻalahi o ka hoʻokō ʻana i nā ʻōnaehana CRLH e pili ana i ka SMT ma ke ʻano o ka nānā ʻana a me ka hoʻolālā. ʻO kēia ma muli o ka loaʻa ʻana o nā ʻāpana chip SMT ma waho o ka papa, ʻaʻole pono ka hana hou ʻana a me ka hana ʻana i hoʻohālikelike ʻia me nā ʻāpana i hoʻolaha ʻia. Eia nō naʻe, ua hoʻopuehu ʻia ka loaʻa ʻana o nā ʻāpana SMT, a hana pinepine lākou i nā alapine haʻahaʻa (ʻo ia hoʻi, 3-6GHz). No laila, ua kaupalena ʻia nā ʻāpana alapine hana a me nā ʻano pae kikoʻī o nā ʻōnaehana CRLH e pili ana i ka SMT. No ka laʻana, i nā noi radiating, ʻaʻole hiki ke hana ʻia nā ʻāpana chip SMT. Hōʻike ka Kiʻi 6 i kahi ʻano i hoʻolaha ʻia e pili ana iā CRLH-TL. Hoʻomaopopo ʻia ke ʻano e ka capacitance interdigital a me nā laina kaapuni pōkole, e hana ana i ka capacitance series CL a me ka inductance parallel LL o LH. Manaʻo ʻia ka capacitance ma waena o ka laina a me GND ʻo ia ka capacitance RH CR, a ʻo ka inductance i hana ʻia e ka flux magnetic i hoʻokumu ʻia e ke kahe o kēia manawa i loko o ka ʻano interdigital ʻo ia ka inductance RH LR.