2. Kev siv MTM-TL hauv Antenna Systems
Tshooj no yuav tsom mus rau cov khoom siv metamaterial TLs thiab qee qhov ntawm lawv cov ntawv thov feem ntau thiab cuam tshuam rau kev ua tiav ntau yam qauv antenna nrog tus nqi qis, yooj yim tsim khoom, miniaturization, dav bandwidth, siab nce thiab ua haujlwm tau zoo, muaj peev xwm scanning dav thiab qis profile. Lawv tau tham hauv qab no.
1. Broadband thiab ntau zaus antennas
Hauv ib qho TL ib txwm muaj nrog qhov ntev ntawm l, thaum muab lub zaus angular ω0, qhov ntev hluav taws xob (lossis theem) ntawm txoj kab kis tau tuaj yeem suav raws li hauv qab no:
Qhov twg vp sawv cev rau qhov ceev ntawm theem ntawm txoj kab xa xov. Raws li pom tau los ntawm saum toj no, qhov bandwidth sib raug zoo rau pawg qeeb, uas yog qhov derivative ntawm φ nrog rau zaus. Yog li ntawd, thaum qhov ntev ntawm txoj kab xa xov luv dua, qhov bandwidth kuj dav dua. Hauv lwm lo lus, muaj kev sib raug zoo rov qab ntawm qhov bandwidth thiab theem tseem ceeb ntawm txoj kab xa xov, uas yog tsim tshwj xeeb. Qhov no qhia tau hais tias hauv cov voj voog faib tawm ib txwm muaj, qhov bandwidth ua haujlwm tsis yooj yim rau kev tswj hwm. Qhov no tuaj yeem raug suav hais tias yog qhov txwv ntawm cov kab xa xov ib txwm muaj nyob rau hauv cov degrees ntawm kev ywj pheej. Txawm li cas los xij, cov ntsiab lus thauj khoom tso cai rau cov kev ntsuas ntxiv kom siv tau hauv metamaterial TLs, thiab qhov teb theem tuaj yeem tswj tau rau qee qhov. Yuav kom nce qhov bandwidth, nws yog qhov tsim nyog kom muaj qhov nqes hav zoo sib xws ze rau qhov zaus ua haujlwm ntawm cov yam ntxwv dispersion. Artificial metamaterial TL tuaj yeem ua tiav lub hom phiaj no. Raws li txoj hauv kev no, ntau txoj hauv kev rau kev txhim kho qhov bandwidth ntawm antennas tau muab tso rau hauv daim ntawv. Cov kws tshawb fawb tau tsim thiab tsim ob lub antennas broadband uas muaj cov resonators sib cais (saib Daim Duab 7). Cov txiaj ntsig tau pom hauv Daim Duab 7 qhia tau tias tom qab thauj lub nplhaib sib cais resonator nrog lub kav hlau txais xov monopole ib txwm muaj, hom zaus resonant qis yog excited. Qhov loj ntawm lub nplhaib sib cais resonator yog optimized kom ua tiav qhov resonance ze rau ntawm lub kav hlau txais xov monopole. Cov txiaj ntsig qhia tau tias thaum ob lub resonances sib xws, qhov bandwidth thiab cov yam ntxwv ntawm lub kav hlau txais xov tau nce. Qhov ntev thiab dav ntawm lub kav hlau txais xov monopole yog 0.25λ0 × 0.11λ0 thiab 0.25λ0 × 0.21λ0 (4GHz), feem, thiab qhov ntev thiab dav ntawm lub kav hlau txais xov monopole uas thauj nrog lub nplhaib sib cais resonator yog 0.29λ0 × 0.21λ0 (2.9GHz), feem. Rau lub kav hlau txais xov F-puab ib txwm muaj thiab lub kav hlau txais xov T-puab tsis muaj lub nplhaib sib cais resonator, qhov nce siab tshaj plaws thiab kev ua haujlwm ntawm lub zog hluav taws xob ntsuas hauv 5GHz band yog 3.6dBi - 78.5% thiab 3.9dBi - 80.2%, feem. Rau lub antenna uas muaj lub split ring resonator, cov kev ntsuas no yog 4dBi - 81.2% thiab 4.4dBi - 83%, feem, hauv 6GHz band. Los ntawm kev siv lub split ring resonator ua lub load sib phim ntawm lub monopole antenna, 2.9GHz ~ 6.41GHz thiab 2.6GHz ~ 6.6GHz bands tuaj yeem txhawb nqa, sib raug rau fractional bandwidths ntawm 75.4% thiab ~ 87%, feem. Cov txiaj ntsig no qhia tau tias qhov ntsuas bandwidth tau txhim kho los ntawm kwv yees li 2.4 zaug thiab 2.11 zaug piv rau cov monopole antennas ib txwm muaj ntawm qhov loj me me.
Daim Duab 7. Ob lub antennas broadband uas muaj cov resonators split-ring.
Raws li pom hauv Daim Duab 8, cov txiaj ntsig sim ntawm lub kav hlau txais xov monopole compact tau pom. Thaum S11≤- 10 dB, qhov bandwidth ua haujlwm yog 185% (0.115-2.90 GHz), thiab ntawm 1.45 GHz, qhov nce siab tshaj plaws thiab kev ua haujlwm hluav taws xob yog 2.35 dBi thiab 78.8%, feem. Qhov layout ntawm lub kav hlau txais xov zoo ib yam li cov qauv ntawv triangular rov qab-rau-rov qab, uas tau pub los ntawm lub zog faib curvilinear. Lub GND luv luv muaj lub hauv paus stub tso rau hauv qab lub feeder, thiab plaub lub nplhaib qhib resonant tau faib nyob ib puag ncig nws, uas ua rau qhov bandwidth ntawm lub kav hlau txais xov dav dua. Lub kav hlau txais xov hluav taws xob yuav luag omnidirectional, npog feem ntau ntawm VHF thiab S bands, thiab tag nrho cov UHF thiab L bands. Qhov loj me ntawm lub kav hlau txais xov yog 48.32 × 43.72 × 0.8 mm3, thiab qhov loj me hluav taws xob yog 0.235λ0 × 0.211λ0 × 0.003λ0. Nws muaj qhov zoo ntawm qhov me me thiab tus nqi qis, thiab muaj peev xwm thov tau hauv cov kab ke sib txuas lus wireless broadband.
Daim Duab 8: Lub kav hlau txais xov Monopole uas muaj lub resonator sib cais.
Daim Duab 9 qhia txog lub antenna planar uas muaj ob khub ntawm cov xov hlau meander sib txuas ua ke uas tau sib txuas rau lub dav hlau hauv av uas zoo li T luv luv los ntawm ob lub vias. Lub antenna loj yog 38.5 × 36.6 mm2 (0.070λ0 × 0.067λ0), qhov twg λ0 yog qhov wavelength ntawm qhov chaw dawb ntawm 0.55 GHz. Lub antenna tawm omnidirectional hauv E-plane hauv qhov zaus ua haujlwm ntawm 0.55 ~ 3.85 GHz, nrog rau qhov siab tshaj plaws ntawm 5.5dBi ntawm 2.35GHz thiab kev ua haujlwm ntawm 90.1%. Cov yam ntxwv no ua rau lub antenna tsim nyog rau ntau yam kev siv, suav nrog UHF RFID, GSM 900, GPS, KPCS, DCS, IMT-2000, WiMAX, WiFi thiab Bluetooth.
Daim Duab 9 Cov qauv antenna planar uas tau npaj tseg.
2. Lub Kav Hlau Xaim (LWA)
Lub kav hlau txais xov hluav taws xob tshiab yog ib qho ntawm cov ntawv thov tseem ceeb rau kev ua tiav cov khoom siv metamaterial TL. Rau cov kav hlau txais xov hluav taws xob, qhov cuam tshuam ntawm theem tas mus li β ntawm lub kaum sab xis (θm) thiab qhov dav tshaj plaws ntawm lub teeb (Δθ) yog raws li nram no:
L yog qhov ntev ntawm lub kav hlau txais xov, k0 yog tus lej nthwv dej hauv qhov chaw dawb, thiab λ0 yog qhov nthwv dej hauv qhov chaw dawb. Nco ntsoov tias kev tawg tsuas yog tshwm sim thaum |β|
3. Lub kav hlau txais xov xoom-txiav txim siab
Ib qho tshwj xeeb ntawm CRLH metamaterial yog tias β tuaj yeem yog 0 thaum zaus tsis sib npaug rau xoom. Raws li cov khoom no, tus resonator xoom-order tshiab (ZOR) tuaj yeem tsim tau. Thaum β yog xoom, tsis muaj kev hloov pauv theem tshwm sim hauv tag nrho resonator. Qhov no yog vim tias qhov hloov pauv theem tas mus li φ = - βd = 0. Tsis tas li ntawd, qhov resonance tsuas yog nyob ntawm qhov kev thauj khoom reactive thiab yog ywj pheej ntawm qhov ntev ntawm cov qauv. Daim duab 10 qhia tau hais tias lub antenna tau tsim los ntawm kev siv ob thiab peb chav nrog E-puab, thiab tag nrho qhov loj me yog 0.017λ0 × 0.006λ0 × 0.001λ0 thiab 0.028λ0 × 0.008λ0 × 0.001λ0, feem, qhov twg λ0 sawv cev rau qhov wavelength ntawm qhov chaw dawb ntawm cov zaus ua haujlwm ntawm 500 MHz thiab 650 MHz, feem. Lub kav hlau txais xov ua haujlwm ntawm qhov zaus ntawm 0.5-1.35 GHz (0.85 GHz) thiab 0.65-1.85 GHz (1.2 GHz), nrog rau cov bandwidths sib piv ntawm 91.9% thiab 96.0%. Ntxiv rau cov yam ntxwv ntawm qhov me me thiab bandwidth dav, qhov nce thiab ua haujlwm ntawm thawj thiab thib ob antennas yog 5.3dBi thiab 85% (1GHz) thiab 5.7dBi thiab 90% (1.4GHz), feem.
Daim Duab 10 Cov qauv kav hlau txais xov ob-E thiab peb-E uas tau npaj tseg.
4. Qhov Antenna
Muaj ib txoj kev yooj yim uas tau muab los ua kom lub qhov ntawm lub kav hlau txais xov CRLH-MTM loj dua, tab sis nws qhov loj ntawm lub kav hlau txais xov yuav luag tsis hloov pauv. Raws li pom hauv Daim Duab 11, lub kav hlau txais xov suav nrog cov chav CRLH uas tau teeb tsa ntsug rau ib leeg, uas muaj cov kab sib dhos thiab cov kab meander, thiab muaj qhov S-zoo li ntawm daim kab sib dhos. Lub kav hlau txais xov tau pub los ntawm CPW qhov sib phim, thiab nws qhov loj yog 17.5 hli × 32.15 hli × 1.6 hli, sib raug rau 0.204λ0 × 0.375λ0 × 0.018λ0, qhov twg λ0 (3.5GHz) sawv cev rau qhov ntev ntawm qhov chaw dawb. Cov txiaj ntsig qhia tau tias lub kav hlau txais xov ua haujlwm hauv qhov zaus ntawm 0.85-7.90GHz, thiab nws cov bandwidth ua haujlwm yog 161.14%. Qhov nce hluav taws xob siab tshaj plaws thiab kev ua haujlwm ntawm lub kav hlau txais xov tshwm sim ntawm 3.5GHz, uas yog 5.12dBi thiab ~ 80%, feem.
Daim Duab 11 Lub kav hlau txais xov CRLH MTM uas tau npaj tseg.
Yog xav paub ntxiv txog antennas, thov mus saib:
Lub sijhawm tshaj tawm: Lub Yim Hli-30-2024
