I. Chiyambi
Metamatadium imatha kufotokozedwa bwino ngati zida zopangidwira kuti zipange zinthu zina zamagetsi zomwe kulibe mwachilengedwe. Zipangizo zokhala ndi chilolezo chololeza komanso kusokoneza koyipa zimatchedwa ma metamatadium amanzere (LHMs). Ma LHM adaphunziridwa kwambiri m'magulu asayansi ndi mainjiniya. Mu 2003, ma LHM adatchulidwa kuti ndi imodzi mwazinthu khumi zapamwamba zasayansi zomwe zachitika masiku ano ndi magazini ya Science. Ntchito zatsopano, malingaliro, ndi zida zapangidwa pogwiritsa ntchito mawonekedwe apadera a LHM. Njira yotumizira (TL) ndi njira yabwino yopangira yomwe ingathenso kusanthula mfundo za LHM. Poyerekeza ndi ma TL achikhalidwe, gawo lofunikira kwambiri la ma TL a metamaterial ndikuwongolera kwa magawo a TL (kufalikira kosalekeza) ndi kusokoneza kwapakhalidwe. Kuwongolera kwa magawo a metamaterial TL kumapereka malingaliro atsopano pakupanga mapangidwe a tinyanga okhala ndi kukula kophatikizika, magwiridwe antchito apamwamba, ndi ntchito zaposachedwa. Chithunzi 1 (a), (b), ndi (c) chikuwonetsa njira zosataya zoyendera za mzere wakumanja wakumanja (PRH), chingwe chopatsira kumanzere (PLH), ndi chingwe chophatikizira kumanzere kumanja ( CRLH), motero. Monga momwe tawonetsera pa Chithunzi 1 (a), PRH TL yofanana ndi dera lachitsanzo nthawi zambiri imakhala yosakanikirana ndi ma inductance ndi shunt capacitance. Monga tawonetsera pa Chithunzi 1(b), mtundu wozungulira wa PLH TL ndikuphatikiza kwa shunt inductance ndi capacitance ya mndandanda. Pakugwiritsa ntchito, sikutheka kukhazikitsa dera la PLH. Ichi ndi chifukwa chosalephereka parasitic mndandanda inductance ndi shunt capacitance zotsatira. Choncho, zizindikiro za mzere wotumizira kumanzere zomwe zingathe kuzindikirika pakali pano ndizopangidwa ndi dzanja lamanzere ndi lamanja, monga momwe tawonetsera pa Chithunzi 1 (c).
Chithunzi 1 Mitundu yosiyanasiyana yoyendera mizere yopatsirana
Kuchulukirachulukira (γ) kwa mzere wopatsira (TL) kumawerengedwa motere: γ=α+jβ=Sqrt(ZY), pomwe Y ndi Z zimayimira kuvomereza ndi kulepheretsa motsatana. Poganizira za CRLH-TL, Z ndi Y zitha kufotokozedwa motere:
yunifolomu CRLH TL idzakhala ndi ubale wobalalika wotsatira:
Gawo lokhazikika β litha kukhala nambala yeniyeni kapena nambala yongoyerekeza. Ngati β ndi yeniyeni mkati mwa ma frequency angapo, pali passband mkati mwa ma frequency osiyanasiyana chifukwa cha chikhalidwe γ=jβ. Kumbali ina, ngati β ndi nambala yongoyerekeza mkati mwa ma frequency angapo, pali kuyimitsidwa mkati mwa kuchuluka kwa ma frequency chifukwa cha chikhalidwe γ=α. Kuyimitsa uku ndikosiyana ndi CRLH-TL ndipo kulibe PRH-TL kapena PLH-TL. Zithunzi 2 (a), (b), ndi (c) zikuwonetsa mipiringidzo yobalalika (ie, ubale wa ω - β) wa PRH-TL, PLH-TL, ndi CRLH-TL, motsatana. Malingana ndi ma curve obalalika, kuthamanga kwa gulu (vg = ∂ω / ∂β) ndi liwiro la gawo (vp = ω / β) la mzere wotumizira amatha kutengedwa ndikuyesedwa. Kwa PRH-TL, imathanso kuganiziridwa kuchokera pamapindikira kuti vg ndi vp zikufanana (ie, vpvg>0). Kwa PLH-TL, mapindikira akuwonetsa kuti vg ndi vp sizikufanana (ie, vpvg<0). Mapiritsi amtundu wa CRLH-TL akuwonetsanso kukhalapo kwa dera la LH (ie, vpvg <0) ndi dera la RH (ie, vpvg> 0). Monga momwe tikuonera pa Chithunzi 2(c), kwa CRLH-TL, ngati γ ndi nambala yeniyeni yeniyeni, pali gulu loyimitsa.
Chithunzi 2 Mapiritsi obalalika a mizere yopatsirana yosiyana
Kawirikawiri, mndandanda ndi ma resonances ofanana a CRLH-TL ndi osiyana, omwe amatchedwa dziko losalinganika. Komabe, ma frequency a resonance ndi ofanana ndi ofanana, amatchedwa dziko loyenera, ndipo chotsatira chosavuta chofananira chofananira chikuwonetsedwa mu Chithunzi 3(a).
Chithunzi 3 Mtundu wozungulira ndi mayendedwe obalalika a chingwe chophatikizira chamanzere
Kuchulukirachulukira kumawonjezeka, mawonekedwe amtundu wa CRLH-TL amawonjezeka pang'onopang'ono. Izi zili choncho chifukwa kuthamanga kwa gawo (ie, vp=ω/β) kumatengera pafupipafupi. Pafupipafupi, CRLH-TL imayang'aniridwa ndi LH, pomwe ma frequency apamwamba, CRLH-TL imayang'aniridwa ndi RH. Izi zikuwonetsa zapawiri za CRLH-TL. Chithunzi chobalalika cha CRLH-TL chikuwonetsedwa pa chithunzi 3(b). Monga momwe chithunzi 3(b) chikusonyezera, kusintha kuchokera ku LH kupita ku RH kumachitika pa:
Pomwe ω0 ndi ma frequency osinthira. Chifukwa chake, munjira yoyenera, kusintha kosalala kumachitika kuchokera ku LH kupita ku RH chifukwa γ ndi nambala yongoyerekeza. Chifukwa chake, palibe kuyimitsidwa kwa kubalalitsidwa koyenera kwa CRLH-TL. Ngakhale kuti β ndi ziro pa ω0 (yopanda malire ndi kutalika kwa mawonekedwe otsogolera, mwachitsanzo, λg=2π/|β|), mafundewa amafalikirabe chifukwa vg pa ω0 si ziro. Mofananamo, pa ω0, kusintha kwa gawo ndi ziro kwa TL ya kutalika d (ie, φ= - βd=0). Kupititsa patsogolo kwa gawo (ie, φ>0) kumachitika mumtundu wa LH (ie, ω<ω0), ndipo kuchedwa kwa gawo (ie, φ<0) kumachitika mu RH frequency range (ie, ω>ω0). Kwa CRLH TL, kusokoneza kwa chikhalidwe kumafotokozedwa motere:
Kumene ZL ndi ZR ndi zolepheretsa za PLH ndi PRH, motsatana. Kwa vuto losalinganizika, chikhalidwe cha impedance chimadalira pafupipafupi. Equation yomwe ili pamwambayi ikuwonetsa kuti vuto lokhazikika limakhala lodziyimira pawokha, kotero limatha kukhala ndi machesi ambiri a bandwidth. Equation ya TL yotengedwa pamwambapa ndi yofanana ndi magawo omwe amatanthauzira zinthu za CRLH. Kuchulukirachulukira kwa TL ndi γ=jβ=Sqrt(ZY). Poganizira kufalikira kosalekeza kwa zinthuzo (β=ω x Sqrt(εμ)), equation yotsatirayi ingapezeke:
Momwemonso, kulepheretsa kwa TL, mwachitsanzo, Z0=Sqrt(ZY), ndikofanana ndi kusakhazikika kwa zinthu, mwachitsanzo, η=Sqrt(μ/ε), zomwe zimafotokozedwa motere:
Mndandanda wa refractive wa CRLH-TL (ie, n = cβ / ω) ukuwonetsedwa mu Chithunzi 4. Chithunzi 4, refractive index ya CRLH-TL mu LH yake ndi yolakwika ndipo refractive index mu RH yake. range ndi positive.
Mkuyu
1. LC network
Potsitsa ma cell a bandpass LC omwe akuwonetsedwa mu Chithunzi 5(a), CRLH-TL yodziwika bwino yautali d imatha kupangidwa nthawi ndi nthawi kapena mosakhazikika. Nthawi zambiri, kuti muwonetsetse kuwerengera komanso kupanga CRLH-TL, dera liyenera kukhala lokhazikika. Poyerekeza ndi chitsanzo cha Chithunzi 1 (c), selo lozungulira la Chithunzi 5 (a) liribe kukula ndipo kutalika kwa thupi ndi kochepa kwambiri (ie, Δz mu mamita). Poganizira kutalika kwake kwamagetsi θ = Δφ (rad), gawo la selo la LC likhoza kuwonetsedwa. Komabe, kuti muzindikire kukhudzidwa kogwiritsidwa ntchito ndi kuthekera, kutalika kwa thupi p kuyenera kukhazikitsidwa. Kusankhidwa kwaukadaulo wogwiritsa ntchito (monga microstrip, coplanar waveguide, zigawo za pamwamba, etc.) zidzakhudza kukula kwa cell ya LC. Selo la LC la Chithunzi 5 (a) likufanana ndi chitsanzo chowonjezereka cha Chithunzi 1 (c), ndi malire ake p = Δz→ 0. Malinga ndi chikhalidwe chofanana p→ 0 mu Chithunzi 5(b), TL ikhoza kupangidwa (ndi ma cell a cascading LC) omwe ali ofanana ndi yunifolomu yabwino ya CRLH-TL yokhala ndi kutalika d, kuti TL iwoneke yofanana ndi mafunde a electromagnetic.
Chithunzi 5 CRLH TL yochokera pa netiweki ya LC.
Kwa selo la LC, poganizira za nthawi ndi nthawi (PBCs) zofanana ndi chiphunzitso cha Bloch-Floquet, ubale wobalalika wa selo la LC umatsimikiziridwa ndikufotokozedwa motere:
Mndandanda wa impedance (Z) ndi shunt admittance (Y) wa cell ya LC zimatsimikiziridwa ndi ma equations awa:
Popeza kutalika kwamagetsi kwa gawo la LC ndi kochepa kwambiri, kuyerekeza kwa Taylor kungagwiritsidwe ntchito kupeza:
2. Kugwiritsa Ntchito Thupi
M'gawo lapitalo, netiweki ya LC yopangira CRLH-TL yakambidwa. Maukonde a LC oterowo amatha kuzindikirika potengera zigawo zakuthupi zomwe zimatha kupanga mphamvu yofunikira (CR ndi CL) ndi inductance (LR ndi LL). M'zaka zaposachedwa, kugwiritsa ntchito zida za chip mount mount technology (SMT) kapena magawo omwe amagawidwa kwakopa chidwi chachikulu. Microstrip, stripline, coplanar waveguide kapena matekinoloje ena ofanana angagwiritsidwe ntchito kuzindikira zigawo zomwe zagawidwa. Pali zinthu zambiri zomwe muyenera kuziganizira posankha tchipisi ta SMT kapena zida zogawidwa. Mapangidwe a CRLH opangidwa ndi SMT ndiwofala kwambiri komanso osavuta kugwiritsa ntchito pofufuza ndi kupanga. Izi ndichifukwa cha kupezeka kwa zida za SMT chip zomwe sizimafunikira kukonzanso ndi kupanga poyerekeza ndi magawo omwe amagawidwa. Komabe, kupezeka kwa zigawo za SMT zimabalalika, ndipo nthawi zambiri zimangogwira ntchito pafupipafupi (ie, 3-6GHz). Chifukwa chake, mapangidwe a CRLH opangidwa ndi SMT ali ndi ma frequency ochepera komanso mawonekedwe enaake. Mwachitsanzo, pakugwiritsa ntchito ma radiation, zida za SMT chip sizingakhale zotheka. Chithunzi 6 chikuwonetsa kapangidwe kake kogawidwa kutengera CRLH-TL. Mapangidwewa amazindikiridwa ndi interdigital capacitance ndi mizere yaifupi yozungulira, kupanga mndandanda wa capacitance CL ndi parallel inductance LL ya LH motsatana. Kuthekera pakati pa mzere ndi GND kumaganiziridwa kuti ndi RH capacitance CR, ndipo inductance yopangidwa ndi maginito othamanga omwe amapangidwa ndi kutuluka kwaposachedwa mu interdigital structure akuganiza kuti ndi RH inductance LR.
Chithunzi 6 One-dimensional microstrip CRLH TL yopangidwa ndi interdigital capacitors ndi short-line inductors.
Kuti mudziwe zambiri za antennas, chonde pitani:
Nthawi yotumiza: Aug-23-2024
