Izindaba - Ukubuyekezwa Komugqa Wokudluliswa Kwe-Metamaterial

I. Isingeniso
I-Metamatadium ingachazwa kangcono njengezakhiwo eziklanywe ngokwenziwa ukuze zikhiqize izici ezithile zikagesi ezingekho ngokwemvelo. Ama-Metamatadium anokuvunyelwa okunegethivu kanye nokungeneka okunegethivu abizwa ngokuthi i-left-handed metamataries (LHMs). Ama-LHM afundwe kabanzi emiphakathini yesayensi nobunjiniyela. Ngo-2003, ama-LHM aqanjwa njengenye yempumelelo eyishumi ephezulu yesayensi yenkathi yangaleso sikhathi ngumagazini i-Science. Izinhlelo zokusebenza ezintsha, imiqondo, namadivayisi athuthukiswe ngokusebenzisa izici ezihlukile zama-LHM. Indlela yolayini wokudlulisa (TL) iyindlela yokuklama ephumelelayo engaphinda ihlaziye imigomo yama-LHM. Uma kuqhathaniswa nama-TL endabuko, isici esibaluleke kakhulu sama-metamaterial TL ukulawulwa kwamapharamitha we-TL (ukusabalaliswa okungaguquki) kanye nokuvinjwa kwesici. Ukulawulwa kwamapharamitha we-metamaterial TL kunikeza imibono emisha yokuklama izakhiwo ze-antenna ezinosayizi ohlangene, ukusebenza okuphezulu, nemisebenzi yenoveli. Umfanekiso 1 (a), (b), kanye (c) ubonisa amamodeli esekethe angalahleki wolayini wokudlulisela ongakwesokudla ongakwesokudla (PRH), ulayini wokudlulisela ongakwesokunxele (PLH), kanye nolayini wokudlulisela oyinhlanganisela ongakwesokunxele kwesokudla ( CRLH), ngokulandelana. Njengoba kuboniswe kuMfanekiso 1(a), imodeli yesekethe elinganayo ye-PRH TL ngokuvamile iyinhlanganisela yochungechunge lwe-inductance namandla e-shunt. Njengoba kukhonjisiwe kuMfanekiso 1(b), imodeli yesekethe ye-PLH TL iyinhlanganisela ye-shunt inductance namandla ochungechunge. Ezisetshenziswa ezingokoqobo, akunakwenzeka ukusebenzisa isekethe ye-PLH. Lokhu kungenxa yochungechunge lwe-parasitic inductance engagwemeki kanye nemiphumela ye-shunt capacitance. Ngakho-ke, izici zolayini wokudlulisela wesandla sobunxele ongabonakala njengamanje zonke ziyinhlanganisela yesandla sobunxele nesakwesokudla, njengoba kukhonjisiwe kuMfanekiso 1(c).

Umfanekiso 1 Amamodeli esekethe emigqa yokudlulisa ehlukene

I-propagation constant (γ) yolayini wokudlulisela (TL) ibalwa ngokuthi: γ=α+jβ=Sqrt(ZY), lapho u-Y no-Z bemelela ukungena nokuvinjelwa ngokulandelana. Uma kucatshangelwa i-CRLH-TL, Z kanye no-Y ingavezwa kanje:

Iyunifomu ye-CRLH TL izoba nobudlelwano obulandelayo bokuhlakazeka:

Isigaba esingaguquki esingu-β singaba inombolo yangempela noma inombolo ecatshangelwayo nje kuphela. Uma u-β engokoqobo ngokuphelele phakathi kwebanga lefrikhwensi, kukhona ibhendi yokudlula phakathi kwebanga lefrikhwensi ngenxa yesimo γ=jβ. Ngakolunye uhlangothi, uma u-β kuyinombolo ecatshangwayo ngaphakathi kwebanga lefrikhwensi, kukhona ukumiswa phakathi kwebanga lefrikhwensi ngenxa yesimo γ=α. Lesi sitobha sihlukile ku-CRLH-TL futhi asitholakali ku-PRH-TL noma ku-PLH-TL. Izibalo 2 (a), (b), kanye (c) zibonisa amajika okusabalalisa (okungukuthi, ubudlelwano buka-ω - β) be-PRH-TL, PLH-TL, kanye ne-CRLH-TL, ngokulandelana. Ngokusekelwe kumajika okusabalalisa, isivinini seqembu (vg=∂ω/∂β) kanye nesivinini sesigaba (vp=ω/β) somugqa wokudlulisela singatholwa futhi silinganiswe. Ku-PRH-TL, kungase futhi kuqondiswe ejikeni ukuthi i-vg ne-vp ziyahambisana (okungukuthi, vpvg>0). Ku-PLH-TL, ijika libonisa ukuthi i-vg ne-vp azihambelani (okungukuthi, vpvg<0). Ijika lokuhlakazeka le-CRLH-TL futhi libonisa ukuba khona kwesifunda se-LH (okungukuthi, vpvg < 0) kanye nesifunda se-RH (okungukuthi, vpvg > 0). Njengoba kungabonwa kuMfanekiso 2(c), ku-CRLH-TL, uma u-γ kuyinombolo yangempela emsulwa, kunebhendi yokumisa.

Umfanekiso 2 Amajika okusabalalisa emigqa yokudlulisela ehlukene

Ngokuvamile, uchungechunge nama-resonances afanayo we-CRLH-TL ahlukile, okubizwa ngokuthi isimo esingalingani. Kodwa-ke, uma uchungechunge namafrikhwensi eresonance afanayo, kubizwa ngokuthi isimo esilinganiselwe, futhi umphumela wemodeli yesekethe elinganayo eyenziwe lula iboniswa kuMfanekiso 3(a).

Umfanekiso 3 Imodeli yesiyingi kanye nejika lokusabalalisa lolayini oyinhlanganisela wokudlulisela wesandla sobunxele

Njengoba imvamisa ikhula, izici zokuhlakazeka ze-CRLH-TL ziyakhula kancane kancane. Lokhu kungenxa yokuthi isivinini sesigaba (okungukuthi, vp=ω/β) siya ngokuya sincika kufrikhwensi. Kumafrikhwensi aphansi, i-CRLH-TL ibuswa yi-LH, kuyilapho kumafrikhwensi aphezulu, i-CRLH-TL ibuswa i-RH. Lokhu kukhombisa ubunjalo obumbaxambili be-CRLH-TL. I-equilibrium CRLH-TL dispersion diagram ikhonjisiwe kuMfanekiso 3(b). Njengoba kukhonjisiwe kuMfanekiso 3(b), ukuguquka kusuka ku-LH kuya ku-RH kwenzeka:

Lapho u-ω0 eyimvamisa yoshintsho. Ngakho-ke, esimweni esilinganiselwe, uguquko olushelelayo lwenzeka ukusuka ku-LH ukuya ku-RH ngoba u-γ uyinombolo ecatshangelwayo kuphela. Ngakho-ke, asikho isivimbeli sokuhlakazeka kwe-CRLH-TL esele. Nakuba u-β enguziro kokuthi ω0 (isihlobo esingenamkhawulo kubude begagasi obuqondisiwe, okungukuthi, λg=2π/|β|), igagasi lisasabalala ngenxa yokuthi i-vg kokuthi ω0 ayiyena uziro. Ngokufanayo, ku-ω0, ukushintshwa kwesigaba kunguziro ku-TL yobude buka-d (okungukuthi, φ= - βd=0). Ukuqhubekela phambili kwesigaba (okungukuthi, φ>0) kwenzeka kububanzi bemvamisa ye-LH (okungukuthi, ω<ω0), kanye nokuhlehliswa kwesigaba (okungukuthi, φ<0) kwenzeka kububanzi befrikhwensi ye-RH (okungukuthi, ω>ω0). Ku-CRLH TL, isici esivimbelayo sichazwa kanje:

Lapho i-ZL ne-ZR kuyizithiyo ze-PLH ne-PRH, ngokulandelana. Ngecala elingalingani, i-impedance yesici incike emvamisa. I-equation engenhla ibonisa ukuthi icala elilinganisiwe lizimele ku-frequency, ngakho-ke lingaba nomdlalo obanzi womkhawulokudonsa. Isibalo se-TL esitholwe ngenhla sifana namapharamitha ayisisekelo achaza okokusebenza kwe-CRLH. Ukusabalalisa okungaguquki kwe-TL ngu-γ=jβ=Sqrt(ZY). Uma kubhekwa ukungaguquguquki kokusakazwa kwempahla (β=ω x Sqrt(εμ)), isibalo esilandelayo singatholakala:

Ngokufanayo, isici sokuthikamezeka kwe-TL, okungukuthi, Z0=Sqrt(ZY), sifana nokuvinjwa kwesici sento, okungukuthi, η=Sqrt(μ/ε), evezwa ngokuthi:

Inkomba ye-refractive ye-CRLH-TL ebhalansile nengalingani (okungukuthi, n = cβ/ω) iboniswa kuMfanekiso 4. Kumfanekiso 4, inkomba ye-refractive ye-CRLH-TL kububanzi bayo be-LH iyinegethivu futhi inkomba ye-refractive ku-RH yayo. ububanzi buphozithivu.

I-Fig. 4 Izinkomba ze-refractive ezijwayelekile zama-CRLH TL abhalansile nangalingani.

1. Inethiwekhi ye-LC
Ngokukhipha amaseli e-LC e-bandpass aboniswe kuMfanekiso 5(a), i-CRLH-TL evamile enobude obufanayo obusebenzayo d ingakhiwa ngezikhathi ezithile noma ngezinye izikhathi. Ngokuvamile, ukuze kuqinisekiswe ukuthi kulula ukubala nokwenza i-CRLH-TL, isekethe idinga ukwenziwa ngezikhathi ezithile. Uma kuqhathaniswa nemodeli yoMfanekiso 1(c), iseli yesekethe yoMfanekiso 5(a) ayinabo usayizi futhi ubude bomzimba buncane ngokungenakulinganiswa (okungukuthi, Δz ngamamitha). Uma kucatshangelwa ubude bayo kagesi θ=Δφ (rad), isigaba seseli ye-LC singavezwa. Kodwa-ke, ukuze ukwazi ukubona i-inductance esetshenzisiwe kanye namandla, ubude bomzimba u-p budinga ukusungulwa. Ukukhethwa kobuchwepheshe bokusebenza (okufana ne-microstrip, i-coplanar waveguide, izingxenye zokukhweza phezulu, njll.) kuzothinta usayizi wenyama weseli ye-LC. Iseli ye-LC yoMfanekiso 5(a) ifana nemodeli ekhulayo yoMfanekiso 1(c), kanye nomkhawulo wayo p=Δz→0. Ngokwesimo sokufana p→0 kuMfanekiso 5(b), i-TL ingakhiwa (ngamaseli e-LC aphumayo) elingana neyunifomu efanelekile ye-CRLH-TL enobude d, ukuze i-TL ibonakale ifana namagagasi kagesi.

Umfanekiso 5 CRLH TL osuselwe kunethiwekhi ye-LC.

Kuseli ye-LC, uma kucatshangelwa izimo zemingcele yezikhathi (PBCs) ezifana nethiyori ye-Bloch-Floquet, ubudlelwano bokuhlakazeka kweseli ye-LC bufakazelwa futhi buvezwa ngale ndlela elandelayo:

Uchungechunge lwe-impedance (Z) kanye ne-shunt admittance (Y) yeseli ye-LC kunqunywa izibalo ezilandelayo:

Njengoba ubude bakagesi besekethe yeyunithi ye-LC buncane kakhulu, ukulinganisa kukaTaylor kungasetshenziswa ukuthola:

2. Ukusebenza ngokomzimba
Esigabeni esidlule, inethiwekhi ye-LC yokwenza i-CRLH-TL kuxoxiwe ngayo. Amanethiwekhi anjalo e-LC angenziwa kuphela ngokwamukela izingxenye zomzimba ezingakhiqiza amandla adingekayo (CR kanye ne-CL) kanye ne-inductance (LR ne-LL). Eminyakeni yakamuva, ukusetshenziswa kwezingxenye ze-chip technology (SMT) noma izingxenye ezisabalalisiwe kudonse isasasa elikhulu. I-Microstrip, i-stripline, i-coplanar waveguide noma obunye ubuchwepheshe obufanayo bungasetshenziswa ukuqaphela izingxenye ezisabalalisiwe. Kunezici eziningi okufanele zicatshangelwe lapho ukhetha ama-SMT chips noma izingxenye ezisabalalisiwe. Izakhiwo ze-CRLH ezisekelwe ku-SMT zivame kakhulu futhi kulula ukuzisebenzisa mayelana nokuhlaziya nokuklama. Lokhu kungenxa yokutholakala kwezingxenye ze-chip ye-SMT ezingekho eshalofini, ezingadingi ukulungiswa kabusha nokukhiqizwa uma kuqhathaniswa nezingxenye ezisabalalisiwe. Nokho, ukutholakala kwezingxenye ze-SMT kuhlakazekile, futhi ngokuvamile zisebenza kuphela kumafrikhwensi aphansi (okungukuthi, 3-6GHz). Ngakho-ke, izakhiwo ze-CRLH ezisekelwe ku-SMT zinebanga lemvamisa yokusebenza elinganiselwe kanye nezici ezithile zesigaba. Isibonelo, ezinhlelweni ezikhipha imisebe, izingxenye ze-chip ye-SMT zingase zingenzeki. Umfanekiso 6 ubonisa isakhiwo esabalalisiwe esisekelwe ku-CRLH-TL. Isakhiwo sibonakala nge-interdigital capacitance kanye nemigqa ye-short-circuit, okwenza uchungechunge lwe-capacitance CL kanye ne-parallel inductance LL ye-LH ngokulandelanayo. I-capacitance phakathi komugqa ne-GND ithathwa njenge-RH capacitance CR, futhi i-inductance eyenziwa yi-flux magnetic eyakhiwe ukugeleza kwamanje esakhiweni se-interdigital kucatshangwa ukuthi i-RH inductance LR.