Qhov kev ua haujlwm no nthuav tawm cov kev sib txuas ua ke ntawm ntau qhov kev tawm tswv yim ntau qhov tso tawm (MIMO) metasurface (MS) wideband kav hlau txais xov rau sub-6 GHz thib tsib tiam (5G) kev sib txuas lus wireless. Qhov pom tseeb tshiab ntawm MIMO qhov system tau thov yog nws qhov kev ua haujlwm dav dav, kev nce siab, kev sib tshuam me me, thiab kev sib cais zoo hauv MIMO cov khoom. Lub kav hlau txais xov qhov chaw radiating yog truncated diagonally, ib nrab hauv av, thiab metasurfaces yog siv los txhim kho tus kav hlau txais xov kev ua tau zoo. Lub tswv yim qauv kev sib xyaw ib leeg MS kav hlau txais xov muaj qhov me me ntawm 0.58λ × 0.58λ × 0.02λ. Simulation thiab ntsuas cov txiaj ntsig ua kom pom kev dav dav ntawm 3.11 GHz txog 7.67 GHz, suav nrog qhov nce siab tshaj plaws ntawm 8 dBi. Plaub-txheej MIMO system yog tsim los kom txhua tus kav hlau txais xov yog orthogonal rau ib leeg thaum tswj hwm qhov loj me thiab kev ua haujlwm dav ntawm 3.2 txog 7.6 GHz. Lub tswv yim MIMO qauv yog tsim thiab tsim rau Rogers RT5880 substrate nrog tsawg poob thiab qhov ntev me me ntawm 1.05? 1.05 Nws? 0.02?, thiab nws qhov kev ua tau zoo raug soj ntsuam siv cov lus thov square kaw lub nplhaib resonator array nrog lub nplhaib 10 x 10. Cov khoom siv hauv paus yog tib yam. Cov phiaj xwm rov qab metasurface txo qis cov kav hlau txais xov rov qab hluav taws xob thiab tswj cov khoom siv hluav taws xob, yog li txhim kho cov bandwidth, nce, thiab kev sib cais ntawm MIMO Cheebtsam. Piv nrog cov kav hlau txais xov MIMO uas twb muaj lawm, qhov kev thov 4-chaw nres nkoj MIMO kav hlau txais xov ua tiav qhov nce siab ntawm 8.3 dBi nrog qhov nruab nrab tag nrho kev ua tau zoo txog li 82% hauv 5G sub-6 GHz band thiab pom zoo nrog cov txiaj ntsig ntsuas. Ntxiv mus, tus tsim MIMO kav hlau txais xov qhia tau zoo heev nyob rau hauv cov nqe lus ntawm lub hnab ntawv correlation coefficient (ECC) tsawg dua 0.004, ntau haiv neeg nce (DG) txog 10 dB (> 9.98 dB) thiab siab cais ntawm MIMO Cheebtsam (> 15.5 dB ). yam ntxwv. Yog li, cov lus thov MS-based MIMO kav hlau txais xov lees paub nws qhov kev siv tau rau sub-6 GHz 5G kev sib txuas lus network.
5G thev naus laus zis yog qhov kev vam meej tsis txaus ntseeg hauv kev sib txuas lus wireless uas yuav ua kom muaj kev sib txuas sai thiab ruaj ntseg dua rau ntau lab ntawm cov khoom siv sib txuas, muab cov neeg siv kev paub nrog "zero" latency (latency tsawg dua 1 millisecond), thiab qhia cov thev naus laus zis tshiab, suav nrog cov khoom siv hluav taws xob. Kev kho mob, kev kawm txawj ntse. , cov nroog ntse, tsev ntse, virtual reality (VR), ntse factories thiab Internet of Vehicles (IoV) hloov peb lub neej, zej zog thiab kev lag luam1,2,3. Tsoom Fwv Teb Chaws Kev Sib Txuas Lus (FCC) faib 5G spectrum rau plaub zaus bands4. Cov zaus band hauv qab 6 GHz yog qhov txaus siab rau cov kws tshawb fawb vim nws tso cai rau kev sib txuas lus ntev nrog cov ntaub ntawv siab 5,6. Lub sub-6 GHz 5G spectrum faib rau kev sib txuas lus thoob ntiaj teb 5G yog qhia hauv daim duab 1, qhia tias txhua lub teb chaws tab tom txiav txim siab sub-6 GHz spectrum rau 5G kev sib txuas lus7,8. Kav hlau txais xov yog ib feem tseem ceeb ntawm 5G tes hauj lwm thiab yuav xav tau ntau lub hauv paus chaw nres tsheb thiab cov neeg siv lub davhlau ya nyob twg kav hlau txais xov.
Microstrip patch antennas muaj qhov zoo ntawm qhov nyias nyias thiab cov qauv tiaj tus, tab sis muaj kev txwv hauv bandwidth thiab nce 9,10, ntau qhov kev tshawb fawb tau ua kom nce thiab bandwidth ntawm lub kav hlau txais xov; Nyob rau hauv xyoo tas los no, metasurfaces (MS) tau siv dav hauv cov kav hlau txais xov thev naus laus zis, tshwj xeeb tshaj yog txhawm rau txhim kho qhov nce thiab nce mus txog 11,12, txawm li cas los xij, cov kav hlau txais xov no tau txwv rau ib qho chaw nres nkoj; MIMO thev naus laus zis yog ib qho tseem ceeb ntawm kev sib txuas lus wireless vim tias nws tuaj yeem siv ntau lub kav hlau txais xov ib txhij los xa cov ntaub ntawv, yog li txhim kho cov ntaub ntawv tus nqi, kev ua haujlwm zoo, channel muaj peev xwm, thiab kev ntseeg siab13,14,15. MIMO kav hlau txais xov yog cov muaj peev xwm sib tw rau 5G daim ntawv thov vim tias lawv tuaj yeem xa thiab tau txais cov ntaub ntawv hla ntau txoj hauv kev yam tsis tas yuav muaj lub zog ntxiv 16,17. Qhov kev sib koom ua ke ntawm MIMO cov khoom yog nyob ntawm qhov chaw ntawm MIMO cov ntsiab lus thiab qhov nce ntawm MIMO kav hlau txais xov, uas yog ib qho kev sib tw loj rau cov kws tshawb fawb. Cov duab 18, 19, thiab 20 qhia ntau yam MIMO kav hlau txais xov ua haujlwm hauv 5G sub-6 GHz band, txhua qhov ua tau zoo MIMO cais thiab ua haujlwm tau zoo. Txawm li cas los xij, qhov nce thiab kev khiav hauj lwm bandwidth ntawm cov txheej txheem tau thov no tsawg.
Metamaterials (MMs) yog cov ntaub ntawv tshiab uas tsis muaj nyob hauv cov xwm txheej thiab tuaj yeem tswj cov khoom siv hluav taws xob, yog li kev txhim kho cov kav hlau txais xov 21,22,23,24. MM tam sim no tau siv dav hauv cov kav hlau txais xov tshuab los txhim kho cov qauv hluav taws xob, bandwidth, nce, thiab kev sib cais ntawm cov kav hlau txais xov thiab wireless kev sib txuas lus, raws li tau tham hauv 25, 26, 27, 28. Hauv 2029, plaub lub ntsiab lus MIMO raws li metasurface, nyob rau hauv uas lub kav hlau txais xov seem yog sandwiched ntawm lub metasurface thiab hauv av tsis muaj qhov sib txawv ntawm huab cua, uas txhim kho MIMO kev ua tau zoo. Txawm li cas los xij, qhov kev tsim no muaj qhov loj dua, qis dua kev ua haujlwm zaus thiab cov qauv tsim. Ib qho electromagnetic bandgap (EBG) thiab lub voj hauv av tau suav nrog hauv 2-chaw nres nkoj wideband MIMO kav hlau txais xov los txhim kho qhov kev sib cais ntawm MIMO30 cov khoom. Tus kav hlau txais xov tsim muaj kev ua tau zoo MIMO ntau haiv neeg thiab kev sib cais zoo ntawm ob lub MIMO kav hlau txais xov, tab sis tsuas yog siv ob lub MIMO Cheebtsam, qhov nce yuav tsawg. Tsis tas li ntawd, in31 kuj tau thov kom muaj ultra-wideband (UWB) dual-port MIMO kav hlau txais xov thiab tshawb xyuas nws qhov kev ua tau zoo MIMO siv cov khoom siv metamaterials. Txawm hais tias lub kav hlau txais xov no muaj peev xwm ua haujlwm ntawm UWB, nws qhov nce qis thiab kev sib cais ntawm ob lub kav hlau txais xov tsis zoo. Txoj haujlwm hauv 32 qhia txog 2-chaw nres nkoj MIMO system uas siv electromagnetic bandgap (EBG) reflectors kom nce qhov nce. Txawm hais tias tus tsim kav hlau txais xov array muaj qhov nce siab thiab kev ua tau zoo MIMO ntau haiv neeg, nws qhov loj me ua rau nws nyuaj rau kev siv cov khoom siv sib txuas lus txuas ntxiv mus. Lwm tus kav hlau txais xov hluav taws xob-raws li broadband tau tsim nyob rau hauv 33, qhov twg lub reflector tau koom ua ke hauv qab tus kav hlau txais xov nrog qhov sib txawv loj dua 22 hli, pom qhov nce siab ntawm 4.87 dB. Daim ntawv 34 tsim plaub-chaw nres nkoj MIMO kav hlau txais xov rau mmWave daim ntaub ntawv, uas yog kev koom ua ke nrog MS txheej los txhim kho kev sib cais thiab nce ntawm MIMO system. Txawm li cas los xij, lub kav hlau txais xov no muab kev nce qib zoo thiab kev sib cais, tab sis muaj kev txwv bandwidth thiab cov khoom siv tsis zoo vim qhov sib txawv ntawm huab cua loj. Ib yam li ntawd, nyob rau hauv 2015, peb-pair, 4-chaw nres nkoj bowtie-zoo li tus metasurface-integrated MIMO kav hlau txais xov tau tsim rau mmWave kev sib txuas lus nrog qhov siab tshaj plaws nce ntawm 7.4 dBi. B36 MS yog siv nyob rau sab nraub qaum ntawm 5G kav hlau txais xov kom nce tus kav hlau txais xov nce, qhov twg cov metasurface ua raws li qhov cuam tshuam. Txawm li cas los xij, MS qauv yog asymmetric thiab tsis tshua muaj kev mloog tau them rau cov qauv ntawm tes.
Raws li cov kev soj ntsuam saum toj no, tsis muaj ib qho ntawm cov kav hlau txais xov saum toj no muaj qhov nce siab, kev sib cais zoo heev, MIMO kev ua tau zoo thiab kev pabcuam dav dav. Yog li ntawd, tseem xav tau ib lub kav hlau txais xov metasurface MIMO uas tuaj yeem npog ntau yam ntawm 5G spectrum zaus hauv qab 6 GHz nrog kev nce siab thiab kev sib cais. Xav txog cov kev txwv ntawm cov ntaub ntawv uas tau hais los saum toj no, qhov dav dav plaub lub ntsiab lus MIMO kav hlau txais xov nrog kev nce siab thiab kev ua tau zoo sib txawv yog npaj rau sub-6 GHz wireless kev sib txuas lus. Tsis tas li ntawd, cov kav hlau txais xov MIMO nthuav tawm kev sib cais zoo heev ntawm MIMO cov khoom, cov khoom me me, thiab cov hluav taws xob ua haujlwm siab. Lub kav hlau txais xov thaj yog truncated diagonally thiab muab tso rau sab saum toj ntawm lub metasurface nrog ib tug 12 hli huab cua sib txawv, uas qhia rov qab hluav taws xob los ntawm lub kav hlau txais xov thiab txhim kho kav hlau txais xov nce thiab directivity. Tsis tas li ntawd, cov kav hlau txais xov ib leeg tau siv los tsim plaub lub MIMO kav hlau txais xov nrog kev ua tau zoo MIMO los ntawm kev tso txhua tus kav hlau txais xov orthogonally rau ib leeg. Tus tsim MIMO kav hlau txais xov tau muab tso rau saum toj ntawm 10 × 10 MS array nrog tooj liab rov qab los txhim kho kev ua haujlwm emission. Tus qauv tsim muaj kev ua haujlwm dav dav (3.08-7.75 GHz), siab nce ntawm 8.3 dBi thiab siab nruab nrab tag nrho kev ua tau zoo ntawm 82%, nrog rau kev sib cais zoo ntawm ntau dua -15.5 dB ntawm MIMO kav hlau txais xov. Tus tsim MS-based MIMO kav hlau txais xov yog simulated siv 3D electromagnetic software pob CST Studio 2019 thiab tau lees paub los ntawm kev sim kev tshawb fawb.
Tshooj lus no muab cov ncauj lus qhia ntxaws ntxaws txog cov txheej txheem tsim qauv thiab ib tus kav hlau txais xov tsim qauv. Tsis tas li ntawd, cov txiaj ntsig tau simulated thiab pom tau raug tham hauv kev nthuav dav, suav nrog kev sib faib tsis tau, nce, thiab tag nrho cov txiaj ntsig nrog thiab tsis muaj metasurfaces. Tus qauv kav hlau txais xov yog tsim los ntawm Rogers 5880 tsawg poob dielectric substrate nrog lub thickness ntawm 1.575mm nrog ib tug dielectric tas li ntawm 2.2. Txhawm rau tsim thiab simulate tus tsim, lub tshuab electromagnetic simulator pob CST studio 2019 tau siv.
Daim duab 2 qhia txog cov qauv tsim qauv thiab tsim qauv ntawm ib lub kav hlau txais xov. Raws li kev tsim ua lej zoo sib npaug 37, lub kav hlau txais xov muaj cov kab hluav taws xob sib npaug ntawm cov kab hluav taws xob thiab lub dav hlau hauv av (raws li tau piav qhia hauv kauj ruam 1) thiab resonates nrog ib qho nqaim bandwidth ntawm 10.8 GHz, raws li qhia hauv daim duab 3b. Thawj qhov loj ntawm tus kav hlau txais xov radiator yog txiav txim siab los ntawm cov lej hauv qab no 37:
Qhov twg \(P_{L}\) thiab \(P_{w}\) yog qhov ntev thiab dav ntawm thaj, c sawv cev rau qhov ceev ntawm lub teeb, \(\gamma_{r}\) yog qhov dielectric tas li ntawm lub substrate . , \(\gamma_{reff }\) sawv cev rau qhov zoo dielectric nqi ntawm qhov chaw hluav taws xob, \(\Delta L\) sawv cev qhov kev hloov ntawm qhov ntev. Lub kav hlau txais xov backplane tau ua kom zoo nyob rau theem thib ob, ua kom lub impedance bandwidth txawm tias qhov impedance bandwidth tsawg heev ntawm 10 dB. Nyob rau theem thib peb, txoj hauj lwm feeder yog txav mus rau sab xis, uas txhim kho cov impedance bandwidth thiab impedance txuam ntawm lub tswv yim kav hlau txais xov 38. Nyob rau theem no, tus kav hlau txais xov qhia tau zoo heev ua haujlwm bandwidth ntawm 4 GHz thiab tseem npog cov spectrum hauv qab 6 GHz hauv 5G. Qhov thib plaub thiab zaum kawg theem yuav etching square grooves nyob rau hauv opposite fab ntawm qhov chaw hluav taws xob. Qhov no nthuav dav 4.56 GHz bandwidth kom npog sub-6 GHz 5G spectrum los ntawm 3.11 GHz txog 7.67 GHz, raws li qhia hauv daim duab 3b. Pem hauv ntej thiab hauv qab kev pom ntawm qhov kev tsim qauv tau pom nyob rau hauv daim duab 3a, thiab qhov kawg optimized yuav tsum tau tsim tsis muaj raws li nram no: SL = 40 mm, Pw = 18 mm, PL = 18 mm, gL = 12 mm, fL = 11. mm, fW = 4 .7 mm, c1 = 2 mm, c2 = 9.65 mm, c3 = 1.65 mm.
(a) Sab saum toj thiab nram qab saib ntawm tus tsim ib lub kav hlau txais xov (CST STUDIO SUITE 2019). (b) S-parameter nkhaus.
Metasurface yog ib lo lus uas hais txog ib ntus ntawm chav tsev cell nyob ntawm qhov deb ntawm ib leeg. Metasurfaces yog ib txoj hauv kev zoo los txhim kho cov kav hlau txais xov hluav taws xob, suav nrog bandwidth, nce, thiab kev sib cais ntawm MIMO Cheebtsam. Vim muaj kev cuam tshuam ntawm kev nthuav dav nthwv dej saum npoo av, metasurfaces tsim cov resonances ntxiv uas ua rau kev txhim kho kav hlau txais xov zoo39. Txoj haujlwm no tau tshaj tawm cov epsilon-negative metamaterial (MM) chav ua haujlwm hauv 5G band hauv qab 6 GHz. Lub MM nrog thaj tsam ntawm 8mm × 8mm tau tsim los ntawm qhov poob qis Rogers 5880 substrate nrog dielectric qhov tsis tu ncua ntawm 2.2 thiab lub thickness ntawm 1.575mm. Qhov optimized MM resonator thaj muaj ib lub nplhaib sab hauv lub voj voog txuas nrog rau ob qhov hloov pauv sab nraud, raws li qhia hauv daim duab 4a. Daim duab 4a qhia txog qhov kawg optimized parameters ntawm lub tswv yim MM teeb. Tom qab ntawd, 40 × 40 mm thiab 80 × 80 mm metasurface txheej tau tsim tsis muaj tooj liab backplane thiab nrog ib tug tooj liab backplane siv 5 × 5 thiab 10 × 10 cell arrays, feem. Lub tswv yim MM qauv tau ua qauv siv 3D electromagnetic qauv software "CST studio suite 2019". Ib qho qauv tsim ntawm cov qauv MM array thiab ntsuas kev teeb tsa (dual-port network analyzer PNA thiab waveguide chaw nres nkoj) tau qhia hauv daim duab 4b kom siv tau cov txiaj ntsig CST simulation los ntawm kev tshuaj xyuas cov lus teb tiag. Kev ntsuas kev ntsuas tau siv Agilent PNA series network analyzer ua ke nrog ob lub waveguide coaxial adapters (A-INFOMW, ntu naj npawb: 187WCAS) xa thiab txais cov teeb liab. Tus qauv 5 × 5 array tau muab tso rau ntawm ob lub waveguide coaxial adapters txuas nrog coaxial cable rau ob lub chaw nres nkoj network analyzer (Agilent PNA N5227A). Agilent N4694-60001 calibration kit yog siv los calibrate lub network analyzer nyob rau hauv ib tug pilot cog. Cov kev simulated thiab CST tau pom qhov sib txawv ntawm cov qauv MM array tau pom nyob rau hauv daim duab 5a. Nws tuaj yeem pom tau tias qhov kev thov MM qauv resonates hauv 5G ntau zaus hauv qab 6 GHz. Txawm hais tias qhov sib txawv me me hauv bandwidth ntawm 10 dB, qhov simulated thiab kev sim tau zoo sib xws. Lub resonant zaus, bandwidth, thiab amplitude ntawm qhov pom resonance yog me ntsis txawv ntawm cov simulated sawv daws yuav, raws li qhia nyob rau hauv daim duab 5a. Cov kev sib txawv ntawm kev soj ntsuam thiab simulated cov txiaj ntsig yog vim kev tsim khoom tsis zoo, kev tshem tawm me me ntawm tus qauv thiab cov chaw nres nkoj waveguide, coupling cuam tshuam ntawm waveguide ports thiab array Cheebtsam, thiab kev ntsuas kam rau ua. Tsis tas li ntawd, qhov kev tso kawm kom raug ntawm tus qauv tsim ntawm cov chaw nres nkoj waveguide hauv kev sim teeb tsa yuav ua rau muaj kev hloov pauv hloov. Tsis tas li ntawd, cov suab nrov tsis xav tau raug pom thaum lub sijhawm ntsuas ntsuas, uas ua rau muaj qhov tsis sib xws ntawm cov lej thiab ntsuas ntsuas. Txawm li cas los xij, sib nrug los ntawm cov teeb meem no, qhov kev thov MM array qauv ua tau zoo vim muaj kev sib raug zoo ntawm kev sim thiab kev sim, ua rau nws zoo haum rau sub-6 GHz 5G wireless kev sib txuas lus daim ntawv thov.
(a) Chav cell geometry (S1 = 8 mm, S2 = 7 mm, S3 = 5 mm, f1, f2, f4 = 0.5 mm, f3 = 0.75 mm, h1 = 0.5 mm, h2 = 1.75 mm) (CST STUDIO SUITE) ) 2019) (b) Daim duab ntawm MM ntsuas kev teeb tsa.
(a) Kev sim thiab kev txheeb xyuas ntawm qhov ntsuas qhov ntsuas qhov nkhaus ntawm cov qauv metamaterial. (b) Dielectric qhov nkhaus ntawm MM unit cell.
Cov yam ntxwv muaj txiaj ntsig zoo xws li qhov ua tau zoo dielectric tas li, sib nqus permeability, thiab qhov ntsuas qhov cuam tshuam tau raug kawm siv cov txheej txheem tom qab ua tiav ntawm CST electromagnetic simulator txhawm rau txheeb xyuas tus cwj pwm ntawm MM unit cell. Qhov zoo ntawm MM tsis yog tau los ntawm kev sib faib tsis tau siv txoj kev tsim kho kom zoo. Cov nram qab no transmittance thiab reflection coefficient sib npaug: (3) thiab (4) tuaj yeem siv los txiav txim siab qhov ntsuas qhov cuam tshuam thiab impedance (saib 40).
Qhov tiag thiab xav txog qhov chaw ntawm tus neeg teb xov tooj yog sawv cev los ntawm (.)' thiab (.)” raws li, thiab tus lej tus nqi m sib raug rau qhov ntsuas qhov tseeb. Dielectric qhov tsis tu ncua thiab permeability yog txiav txim los ntawm cov qauv \(\varepsilon { } = { }n/z,\) thiab \(\mu = nz\), uas yog raws li impedance thiab refractive index, feem. Qhov zoo ntawm dielectric qhov nkhaus ntawm MM qauv yog qhia hauv daim duab 5b. Ntawm qhov resonant zaus, qhov ua tau zoo dielectric tas li yog qhov tsis zoo. Daim duab 6a, b qhia cov txiaj ntsig ntawm cov txiaj ntsig zoo permeability (μ) thiab cov txiaj ntsig zoo refractive index (n) ntawm lub tswv yim chav cell. Qhov tseem ceeb, cov ntawv rho tawm tau nthuav tawm cov txiaj ntsig zoo tiag tiag ze rau xoom, uas lees paub cov khoom ntawm epsilon-negative (ENG) ntawm cov qauv MM. Ntxiv mus, raws li pom nyob rau hauv daim duab 6a, lub resonance ntawm permeability zero yog muaj feem xyuam rau lub resonant zaus. Lub tsev cell tsim muaj qhov tsis zoo refractive Performance index (Fig. 6b), uas txhais tau hais tias qhov kev thov MM tuaj yeem siv los txhim kho cov kav hlau txais xov kev ua tau zoo21,41.
Tus qauv tsim ntawm ib lub kav hlau txais xov broadband tau tsim los sim sim cov qauv tsim. Daim duab 7a, b qhia cov duab ntawm cov qauv tsim qauv ib lub kav hlau txais xov, nws cov khoom siv thiab cov teeb tsa nyob ze (SATIMO). Txhawm rau txhim kho lub kav hlau txais xov kev ua tau zoo, qhov tsim metasurface tau muab tso rau hauv cov khaubncaws sab nraud povtseg hauv qab lub kav hlau txais xov, raws li pom hauv daim duab 8a, nrog qhov siab h. Ib qho 40mm x 40mm ob txheej txheej metasurface tau siv rau tom qab ntawm tib lub kav hlau txais xov ntawm 12 hli ntu. Tsis tas li ntawd, ib qho metasurface nrog lub nraub qaum yog muab tso rau sab nraub qaum ntawm ib lub kav hlau txais xov ntawm qhov deb ntawm 12 hli. Tom qab siv cov metasurface, ib lub kav hlau txais xov qhia tau hais tias muaj kev txhim kho tseem ceeb hauv kev ua tau zoo, raws li pom nyob rau hauv daim duab 1 thiab 2. Daim duab 8 thiab 9. Daim duab 8b qhia txog qhov simulated thiab ntsuas qhov xav tau rau ib lub kav hlau txais xov tsis muaj thiab nrog cov metasurfaces. Nws yog ib nqi sau cia hais tias qhov kev pab them nqi band ntawm ib tug kav hlau txais xov nrog ib tug metasurface yog heev zoo ib yam li cov kev pab them nqi band ntawm ib tug kav hlau txais xov tsis muaj ib tug metasurface. Daim duab 9a, b qhia qhov sib piv ntawm qhov simulated thiab pom ib tus kav hlau txais xov nce thiab kev ua haujlwm tag nrho tsis muaj thiab nrog MS hauv kev ua haujlwm spectrum. Nws tuaj yeem pom tau tias, piv nrog cov kav hlau txais xov tsis-metasurface, qhov nce ntawm lub kav hlau txais xov metasurface tau zoo dua, nce ntawm 5.15 dBi mus rau 8 dBi. Qhov nce ntawm ib txheej txheej metasurface, dual-txheej metasurface, thiab ib lub kav hlau txais xov nrog lub nraub qaum metasurface tau nce los ntawm 6 dBi, 6.9 dBi, thiab 8 dBi, feem. Piv nrog rau lwm cov metasurfaces (ib-txheej thiab ob-txheej MCs), qhov nce ntawm ib lub kav hlau txais xov metasurface nrog tooj liab backplane yog txog 8 dBi. Nyob rau hauv cov ntaub ntawv no, lub metasurface ua raws li ib tug reflector, txo tus kav hlau txais xov rov qab hluav taws xob thiab manipulating lub electromagnetic nthwv dej nyob rau hauv-theem, yog li ua kom lub kav hlau txais xov hluav taws xob efficiency thiab li no nce. Kev kawm txog kev ua tau zoo tag nrho ntawm ib lub kav hlau txais xov tsis muaj thiab nrog cov metasurfaces yog qhia hauv daim duab 9b. Nws yog ib qho tsim nyog sau cia tias qhov ua tau zoo ntawm lub kav hlau txais xov nrog thiab tsis muaj qhov metasurface yuav luag zoo ib yam. Nyob rau hauv qis zaus ntau, tus kav hlau txais xov efficiency txo me ntsis. Cov kev sim thiab simulated nce thiab kev ua tau zoo nkhaus yog pom zoo. Txawm li cas los xij, muaj qhov sib txawv me ntsis ntawm qhov simulated thiab kuaj cov txiaj ntsig vim kev tsim khoom tsis xws luag, kev ntsuas qhov siab, SMA qhov chaw nres nkoj kev sib txuas, thiab xaim poob. Tsis tas li ntawd, lub kav hlau txais xov thiab MS reflector nyob nruab nrab ntawm cov nylon spacers, uas yog lwm qhov teeb meem uas cuam tshuam rau cov txiaj ntsig tau pom zoo piv rau cov txiaj ntsig simulation.
Daim duab (a) qhia qhov ua tiav ib lub kav hlau txais xov thiab nws cov khoom sib txuas. (b) Kev ntsuas qhov ze ntawm thaj chaw (SATIMO).
(a) Kav hlau txais xov excitation siv metasurface reflectors (CST STUDIO SUITE 2019). (b) Simulated thiab sim reflectances ntawm ib lub kav hlau txais xov tsis muaj thiab nrog MS.
Kev simulation thiab ntsuas cov txiaj ntsig ntawm (a) qhov ua tiav qhov nce thiab (b) tag nrho cov txiaj ntsig ntawm cov kav hlau txais xov metasurface.
Beam qauv tsom xam siv MS. Kev ntsuas ib leeg nyob ze ntawm thaj chaw tau ua nyob rau hauv SATIMO Near-Field Experimental Ib puag ncig ntawm UKM SATIMO Near-Field Systems Laboratory. Daim duab 10a, b qhia cov simulated thiab soj ntsuam E-dav hlau thiab H-dav hlau hluav taws xob qauv ntawm 5.5 GHz rau lub tswv yim ib lub kav hlau txais xov nrog thiab tsis muaj MS. Tus tsim ib lub kav hlau txais xov (tsis muaj MS) muab cov qauv hluav taws xob zoo ib yam nrog rau sab lobe qhov tseem ceeb. Tom qab siv cov lus pom zoo MS reflector, tus kav hlau txais xov muab cov qauv hluav taws xob unidirectional thiab txo cov theem ntawm lub nraub qaum, raws li pom hauv daim duab 10a, b. Nws yog ib nqi sau cia hais tias lub tswv yim ib tug kav hlau txais xov hluav taws xob qauv yog ruaj khov thiab unidirectional nrog tsawg heev rov qab thiab sab lobes thaum siv ib tug metasurface nrog ib tug tooj liab backplane. Lub tswv yim MM array reflector txo lub nraub qaum thiab sab lobes ntawm tus kav hlau txais xov thaum txhim kho cov hluav taws xob kev ua tau zoo los ntawm kev coj cov tam sim no nyob rau hauv unidirectional cov lus qhia (Fig. 10a, b), yog li ua kom qhov nce thiab ncaj qha. Nws tau pom tias qhov kev sim ntsuas hluav taws xob yuav luag piv rau CST simulations, tab sis sib txawv me ntsis vim qhov tsis sib xws ntawm ntau cov khoom sib dhos, ntsuas qhov siab, thiab kev poob qis. Tsis tas li ntawd, ib lub nylon spacer tau muab tso rau ntawm lub kav hlau txais xov thiab MS reflector, uas yog lwm qhov teeb meem cuam tshuam rau cov txiaj ntsig tau pom zoo piv rau cov txiaj ntsig ntawm cov lej.
Cov qauv hluav taws xob ntawm tus tsim ib lub kav hlau txais xov (tsis muaj MS thiab nrog MS) ntawm qhov zaus ntawm 5.5 GHz tau simulated thiab sim.
Daim ntawv thov MIMO kav hlau txais xov geometry yog qhia hauv daim duab 11 thiab suav nrog plaub tus kav hlau txais xov. Plaub yam ntawm MIMO kav hlau txais xov yog teem rau ib leeg rau ib leeg ntawm ib lub substrate ntawm qhov ntev 80 × 80 × 1.575 mm, raws li qhia nyob rau hauv daim duab 11. Tus tsim MIMO kav hlau txais xov muaj ib tug inter-element nrug ntawm 22 hli, uas yog me dua lub qhov ze tshaj qhov sib cuam tshuam cov ntsiab lus nyob deb ntawm lub kav hlau txais xov. MIMO kav hlau txais xov tsim. Tsis tas li ntawd, ib feem ntawm lub dav hlau hauv av yog nyob rau hauv tib txoj kev raws li ib tug kav hlau txais xov. Qhov kev cuam tshuam qhov tseem ceeb ntawm MIMO kav hlau txais xov (S11, S22, S33, thiab S44) qhia hauv daim duab 12a qhia txog tus cwj pwm zoo ib yam li cov kav hlau txais xov ib leeg resonating hauv 3.2–7.6 GHz band. Yog li, lub impedance bandwidth ntawm MIMO kav hlau txais xov yog raws nraim tib yam li ntawm ib lub kav hlau txais xov. Cov nyhuv coupling ntawm MIMO Cheebtsam yog lub ntsiab yog vim li cas rau qhov me me bandwidth poob ntawm MIMO kav hlau txais xov. Daim duab 12b qhia txog qhov cuam tshuam ntawm kev sib tshuam ntawm MIMO Cheebtsam, qhov twg qhov kev pom zoo ntawm kev sib cais ntawm MIMO Cheebtsam tau txiav txim siab. Qhov kev sib cais ntawm cov kav hlau txais xov 1 thiab 2 yog qhov qis tshaj ntawm -13.6 dB, thiab kev sib cais ntawm cov kav hlau txais xov 1 thiab 4 yog qhov siab tshaj plaws ntawm -30.4 dB. Vim nws qhov me me thiab dav bandwidth, MIMO kav hlau txais xov muaj qhov nce thiab qis dua. Rwb thaiv tsev tsis tshua muaj, yog li yuav tsum tau muaj zog ntxiv thiab rwb thaiv tsev;
Tsim cov txheej txheem ntawm kev thov MIMO kav hlau txais xov (a) sab saum toj saib thiab (b) dav hlau hauv av. (CST Studio Suite 2019).
Geometric kev npaj thiab excitation txoj kev ntawm lub tswv yim metasurface MIMO kav hlau txais xov yog qhia nyob rau hauv daim duab 13a. Lub 10x10mm matrix nrog qhov ntev ntawm 80x80x1.575mm yog tsim rau sab nraub qaum ntawm 12 hli siab MIMO kav hlau txais xov, raws li qhia hauv daim duab 13a. Tsis tas li ntawd, metasurfaces nrog tooj liab backplanes yog tsim los siv hauv MIMO kav hlau txais xov los txhim kho lawv cov kev ua tau zoo. Qhov kev ncua deb ntawm lub metasurface thiab MIMO kav hlau txais xov yog qhov tseem ceeb kom ua tiav qhov kev nce siab thaum tso cai rau kev cuam tshuam ntawm cov nthwv dej uas tsim los ntawm tus kav hlau txais xov thiab cov uas cuam tshuam los ntawm cov metasurface. Kev ua qauv dav dav tau ua los txhawm rau txhim kho qhov siab ntawm tus kav hlau txais xov thiab cov metasurface thaum tswj xyuas lub quarter-yoj qauv rau kev nce siab tshaj plaws thiab kev sib cais ntawm MIMO cov ntsiab lus. Qhov kev txhim kho tseem ceeb hauv MIMO kav hlau txais xov kev ua tau zoo ua tiav los ntawm kev siv metasurfaces nrog backplanes piv rau metasurfaces yam tsis muaj backplanes yuav tshwm sim hauv tshooj tom ntej.
(a) CST simulation teeb tsa ntawm qhov kev thov MIMO kav hlau txais xov siv MS (CST STUDIO SUITE 2019), (b) Reflectance curves ntawm cov tsim MIMO system tsis muaj MS thiab nrog MS.
Qhov kev cuam tshuam ntawm MIMO kav hlau txais xov nrog thiab tsis muaj metasurfaces tau pom hauv daim duab 13b, qhov twg S11 thiab S44 tau nthuav tawm vim tias yuav luag zoo ib yam ntawm txhua tus kav hlau txais xov hauv MIMO system. Nws yog tsim nyog sau cia tias -10 dB impedance bandwidth ntawm MIMO kav hlau txais xov tsis muaj thiab nrog ib qho metasurface yuav luag zoo ib yam. Nyob rau hauv sib piv, lub impedance bandwidth ntawm lub tswv yim MIMO kav hlau txais xov yog txhim kho los ntawm dual-txheej MS thiab backplane MS. Nws yog tsim nyog sau cia tias tsis muaj MS, MIMO kav hlau txais xov muab ib feem ntawm bandwidth ntawm 81.5% (3.2-7.6 GHz) txheeb ze rau qhov nruab nrab zaus. Kev sib koom ua ke ntawm MS nrog lub nraub qaum nce qhov impedance bandwidth ntawm MIMO tus kav hlau txais xov rau 86.3% (3.08-7.75 GHz). Txawm hais tias dual-txheej MS nce dhau los, qhov kev txhim kho tsawg dua li ntawm MS nrog tooj liab backplane. Ntxiv mus, ob txheej MC nce qhov loj ntawm lub kav hlau txais xov, nce nws cov nqi, thiab txwv nws qhov ntau. Tus tsim MIMO kav hlau txais xov thiab metasurface reflector yog tsim thiab ua pov thawj kom siv tau cov txiaj ntsig simulation thiab ntsuas qhov ua tau zoo. Daim duab 14a qhia txog kev tsim MS txheej thiab MIMO kav hlau txais xov nrog ntau yam khoom sib dhos, thaum daim duab 14b qhia ib daim duab ntawm MIMO tsim. MIMO kav hlau txais xov yog mounted rau saum lub metasurface siv plaub nylon spacers, raws li qhia nyob rau hauv daim duab 14b. Daim duab 15a qhia tau hais tias ib daim duab ntawm qhov kev sim nyob ze ntawm qhov tsim MIMO kav hlau txais xov. Lub PNA network analyzer (Agilent Technologies PNA N5227A) tau siv los kwv yees qhov tsis sib xws thiab ntsuas thiab ntsuas cov yam ntxwv ze-tawm emission nyob rau hauv UKM SATIMO Near-Field Systems Laboratory.
(a) Cov duab ntawm SATIMO ze-tsav kev ntsuas (b) Simulated thiab sim nkhaus ntawm S11 MIMO kav hlau txais xov nrog thiab tsis muaj MS.
Tshooj lus no nthuav tawm cov kev tshawb fawb sib piv ntawm cov simulated thiab soj ntsuam S-tsis pom kev ntawm 5G MIMO kav hlau txais xov. Daim duab 15b qhia txog qhov kev sim ua kom pom tseeb ntawm kev sib xyaw 4-ntu MIMO MS kav hlau txais xov thiab muab piv nrog CST simulation cov txiaj ntsig. Cov kev sim ntsuas tau pom tias zoo ib yam li CST suav, tab sis txawv me ntsis vim kev tsim khoom tsis raug thiab kev sim siab. Tsis tas li ntawd, qhov pom kev pom ntawm qhov kev thov MS-based MIMO qauv npog 5G spectrum hauv qab 6 GHz nrog impedance bandwidth ntawm 4.8 GHz, uas txhais tau hais tias 5G daim ntawv thov tuaj yeem ua tau. Txawm li cas los xij, qhov ntsuas resonant zaus, bandwidth, thiab amplitude txawv me ntsis ntawm CST simulation cov txiaj ntsig. Kev tsim khoom tsis xws luag, coax-rau-SMA coupling poob, thiab kev ntsuas sab nraum zoov tuaj yeem ua rau muaj qhov sib txawv ntawm qhov ntsuas thiab simulated. Txawm li cas los xij, txawm hais tias qhov tsis zoo no, qhov kev thov MIMO ua tau zoo, muab kev pom zoo zoo ntawm kev sim thiab kev ntsuas, ua rau nws zoo haum rau sub-6 GHz 5G wireless daim ntawv thov.
Lub simulated thiab soj ntsuam MIMO kav hlau txais xov nce nkhaus yog qhia nyob rau hauv daim duab 2 thiab 2. Raws li pom nyob rau hauv daim duab 16a,b thiab 17a,b, raws li, kev sib nrig sib cuam tshuam ntawm MIMO Cheebtsam yog qhia. Thaum cov metasurfaces tau siv rau MIMO kav hlau txais xov, kev sib cais ntawm MIMO kav hlau txais xov zoo dua. Cov phiaj xwm kev sib cais ntawm cov kav hlau txais xov uas nyob ib sab S12, S14, S23 thiab S34 qhia qhov nkhaus zoo sib xws, thaum kab pheeb ces kaum MIMO kav hlau txais xov S13 thiab S42 qhia qhov sib cais siab zoo sib xws vim qhov kev ncua deb ntawm lawv ntau dua. Cov yam ntxwv sib kis tau zoo ntawm cov kav hlau txais xov uas nyob ib sab tau pom hauv daim duab 16a. Nws yog tsim nyog sau cia tias nyob rau hauv 5G kev khiav hauj lwm spectrum hauv qab 6 GHz, qhov tsawg kawg nkaus kev rho tawm ntawm ib tug MIMO kav hlau txais xov tsis muaj ib tug metasurface yog -13.6 dB, thiab rau ib tug metasurface nrog ib tug backplane - 15.5 dB. Cov phiaj xwm nce (Daim duab 16a) qhia tau hais tias lub backplane metasurface tau txhim kho qhov kev sib cais ntawm MIMO kav hlau txais xov ntsiab piv rau ib leeg- thiab ob txheej txheej metasurfaces. Ntawm cov kav hlau txais xov uas nyob ib sab, ib leeg- thiab ob txheej txheej metasurfaces muab qhov kev sib cais yam tsawg kawg nkaus ntawm kwv yees li -13.68 dB thiab -14.78 dB, thiab tooj liab backplane metasurface muab kwv yees li -15.5 dB.
Simulated rho tawm nkhaus ntawm MIMO ntsiab tsis muaj MS txheej thiab nrog MS txheej: (a) S12, S14, S34 thiab S32 thiab (b) S13 thiab S24.
Kev sim nce nkhaus ntawm cov lus thov MS-based MIMO kav hlau txais xov yam tsis muaj thiab nrog: (a) S12, S14, S34 thiab S32 thiab (b) S13 thiab S24.
MIMO kab pheeb ces kaum kav hlau txais xov nce cov phiaj xwm ua ntej thiab tom qab ntxiv MS txheej yog qhia hauv daim duab 16b. Nws yog tsim nyog sau cia tias qhov tsawg kawg nkaus kev sib cais ntawm kab pheeb ces kaum kav hlau txais xov tsis muaj metasurface (antennas 1 thiab 3) yog - 15.6 dB thoob plaws kev khiav hauj lwm spectrum, thiab ib tug metasurface nrog ib tug backplane yog - 18 dB. Txoj hauv kev metasurface txo qhov cuam tshuam ntawm kev sib txuas ntawm kab pheeb ces kaum MIMO kav hlau txais xov. Qhov siab tshaj plaws rwb thaiv tsev rau ib txheej metasurface yog -37 dB, thaum rau ob txheej txheej metasurface no tus nqi poob rau -47 dB. Qhov siab tshaj plaws ntawm kev sib cais ntawm cov metasurface nrog lub tooj liab backplane yog −36.2 dB, uas txo qis nrog ntau zaus. Piv rau ib leeg- thiab ob-txheej metasurfaces yam tsis muaj backplane, metasurfaces nrog lub backplane muab kev sib cais zoo tshaj plaws nyob rau tag nrho cov kev ua haujlwm zaus, tshwj xeeb tshaj yog nyob rau hauv 5G ntau yam hauv qab 6 GHz, raws li qhia hauv daim duab 16a, b. Hauv qhov nrov tshaj plaws thiab dav siv 5G band hauv qab 6 GHz (3.5 GHz), ib leeg- thiab ob txheej txheej metasurfaces muaj kev sib cais qis dua ntawm MIMO cov khoom dua li cov metasurfaces nrog tooj liab backplanes (yuav luag tsis muaj MS) (saib daim duab 16a), b). Kev ntsuas qhov nce tau pom nyob rau hauv daim duab 17a, b, qhia qhov kev sib cais ntawm cov kav hlau txais xov uas nyob ib sab (S12, S14, S34 thiab S32) thiab kab pheeb ces kaum (S24 thiab S13), raws li. Raws li tuaj yeem pom los ntawm cov duab no (Fig. 17a, b), qhov kev sim cais tawm ntawm MIMO cov khoom pom zoo nrog qhov simulated cais. Txawm hais tias muaj qhov sib txawv me me ntawm qhov simulated thiab ntsuas CST qhov tseem ceeb vim kev tsim khoom tsis xws luag, SMA chaw nres nkoj sib txuas thiab xaim poob. Tsis tas li ntawd, lub kav hlau txais xov thiab MS reflector nyob nruab nrab ntawm cov nylon spacers, uas yog lwm qhov teeb meem uas cuam tshuam rau cov txiaj ntsig tau pom zoo piv rau cov txiaj ntsig simulation.
tau kawm txog qhov chaw tam sim no ntawm 5.5 GHz kom rationalize lub luag hauj lwm ntawm metasurfaces nyob rau hauv txo kev sib nrig sib coupling los ntawm nto yoj suppression42. Qhov kev faib tawm tam sim no ntawm tus kav hlau txais xov MIMO tau pom nyob rau hauv daim duab 18, qhov twg kav hlau txais xov 1 tau tsav thiab tus kav hlau txais xov tas li raug txiav nrog 50 ohm load. Thaum lub kav hlau txais xov 1 muaj zog, qhov tseem ceeb ntawm kev sib txuas txuas tam sim no yuav tshwm sim ntawm cov kav hlau txais xov uas nyob ib sab ntawm 5.5 GHz thaum tsis muaj ib qho metasurface, raws li qhia hauv daim duab 18a. Ntawm qhov tsis sib xws, los ntawm kev siv cov metasurfaces, raws li qhia hauv daim duab 18b–d, kev sib cais ntawm cov kav hlau txais xov uas nyob ib sab tau txhim kho. Nws yuav tsum raug sau tseg tias cov txiaj ntsig ntawm kev sib koom ua ke ntawm cov teb uas nyob ib sab tuaj yeem txo qis los ntawm kev nthuav tawm cov kev sib txuas tam sim no rau cov rings uas nyob ib sab ntawm chav tsev thiab cov cell uas nyob ib sab MS nyob rau hauv MS txheej hauv cov lus qhia antiparallel. Txhaj tam sim no los ntawm cov kav hlau txais xov xa mus rau MS units yog ib txoj hauv kev los txhim kho kev sib cais ntawm MIMO cov khoom. Yog li ntawd, qhov sib txuas tam sim no ntawm MIMO cov khoom raug txo qis heev, thiab kev sib cais kuj tseem txhim kho zoo heev. Vim hais tias cov coupling teb yog dav faib nyob rau hauv lub caij, lub tooj liab backplane metasurface cais lub MIMO kav hlau txais xov los ua ke ho ntau tshaj ib- thiab ob-txheej metasurfaces (Daim duab 18d). Ntxiv mus, tus tsim MIMO kav hlau txais xov muaj tsawg heev backpropagation thiab sab propagation, ua ib tug unidirectional hluav taws xob qauv, yog li ua rau kom qhov nce ntawm lub tswv yim MIMO kav hlau txais xov.
Nto cov qauv tam sim no ntawm lub tswv yim MIMO kav hlau txais xov ntawm 5.5 GHz (a) tsis muaj MC, (b) ib txheej MC, (c) ob txheej MC, thiab (d) ib txheej MC nrog tooj liab backplane. (CST Studio Suite 2019).
Tsis pub dhau lub sijhawm ua haujlwm, Daim duab 19a qhia txog kev simulated thiab pom tau zoo ntawm tus tsim MIMO kav hlau txais xov yam tsis muaj thiab nrog metasurfaces. Lub simulated tiav nce ntawm MIMO kav hlau txais xov yam tsis muaj metasurface yog 5.4 dBi, raws li qhia hauv daim duab 19a. Vim muaj kev sib koom ua ke ntawm MIMO Cheebtsam, qhov kev thov MIMO kav hlau txais xov yeej ua tiav 0.25 dBi siab dua li ib lub kav hlau txais xov. Qhov sib ntxiv ntawm cov metasurfaces tuaj yeem muab cov txiaj ntsig tseem ceeb thiab kev sib cais ntawm MIMO Cheebtsam. Yog li, lub tswv yim metasurface MIMO kav hlau txais xov tuaj yeem ua tiav qhov pom tau zoo nce txog 8.3 dBi. Raws li pom nyob rau hauv daim duab 19a, thaum ib qho metasurface siv nyob rau tom qab ntawm MIMO kav hlau txais xov, qhov nce ntawm 1.4 dBi. Thaum cov metasurface yog ob npaug, qhov nce ntxiv los ntawm 2.1 dBi, raws li pom hauv daim duab 19a. Txawm li cas los xij, qhov kev xav tau siab tshaj plaws ntawm 8.3 dBi tau ua tiav thaum siv cov metasurface nrog lub dav hlau tooj liab. Qhov tseem ceeb, qhov siab tshaj plaws tau nce rau ib txheej thiab ob txheej txheej metasurfaces yog 6.8 dBi thiab 7.5 dBi, raws li, thaum qhov siab tshaj plaws tau nce rau hauv qab-txheej metasurface yog 8.3 dBi. Cov txheej txheem metasurface nyob rau sab nraub qaum ntawm tus kav hlau txais xov ua haujlwm raws li qhov cuam tshuam, cuam tshuam cov hluav taws xob los ntawm sab nraub qaum ntawm tus kav hlau txais xov thiab txhim kho qhov sib piv ntawm pem hauv ntej mus rau sab nraub qaum (F / B) ntawm tus tsim MIMO kav hlau txais xov. Tsis tas li ntawd, lub high-impedance MS reflector manipulates electromagnetic vuag nyob rau hauv-theem, yog li tsim ntxiv resonance thiab txhim kho cov hluav taws xob kev ua tau zoo ntawm lub tswv yim MIMO kav hlau txais xov. Lub MS reflector ntsia tom qab MIMO kav hlau txais xov tuaj yeem ua kom qhov kev ua tiav tau zoo, uas tau lees paub los ntawm kev sim cov txiaj ntsig. Qhov kev pom thiab simulated tau txais txiaj ntsig ntawm tus qauv tsim MIMO kav hlau txais xov yuav luag zoo ib yam, txawm li cas los xij, ntawm qee zaus qhov ntsuas tau nce siab dua qhov kev simulated nce, tshwj xeeb tshaj yog rau MIMO tsis muaj MS; Cov kev hloov pauv hauv kev sim nce no yog vim kev ntsuas qhov siab ntawm cov nylon ncoo, cable poob, thiab txuas txuas hauv lub kav hlau txais xov. Lub ncov ntsuas qhov nce ntawm MIMO kav hlau txais xov yam tsis muaj qhov metasurface yog 5.8 dBi, thaum lub metasurface nrog tooj liab backplane yog 8.5 dBi. Nws yog ib qho tsim nyog sau cia tias qhov kev thov ua tiav 4-chaw nres nkoj MIMO kav hlau txais xov nrog MS reflector nthuav tawm qhov nce siab hauv kev sim thiab cov lej.
Kev simulation thiab kev sim cov txiaj ntsig ntawm (a) qhov ua tiav qhov nce thiab (b) tag nrho kev ua tau zoo ntawm MIMO kav hlau txais xov nrog cov nyhuv metasurface.
Daim duab 19b qhia tag nrho cov kev ua tau zoo ntawm kev thov MIMO system yam tsis muaj thiab nrog metasurface reflectors. Hauv daim duab 19b, qhov ua tau zoo tshaj plaws uas siv MS nrog rov qab yog tshaj 73% (txog 84%). Tag nrho cov kev ua tau zoo ntawm cov tsim MIMO kav hlau txais xov tsis muaj MC thiab nrog MC yog yuav luag zoo ib yam nrog me me sib txawv piv rau cov nqi simulated. Yog vim li cas rau qhov no yog kev ntsuas siab thiab kev siv spacers ntawm tus kav hlau txais xov thiab MS reflector. Qhov ntsuas tau ua tiav thiab kev ua tau zoo tag nrho thoob plaws tag nrho cov zaus yuav luag zoo ib yam li cov txiaj ntsig simulation, qhia tias qhov kev ua tau zoo ntawm MIMO tus qauv yog raws li qhov xav tau thiab pom zoo MS-based MIMO kav hlau txais xov yog tsim rau 5G kev sib txuas lus. Vim yog qhov yuam kev hauv kev sim kev tshawb fawb, qhov sib txawv muaj nyob nruab nrab ntawm tag nrho cov txiaj ntsig ntawm kev sim sim thiab cov txiaj ntsig ntawm kev simulations. Qhov kev ua tau zoo ntawm cov qauv tsim tau cuam tshuam los ntawm impedance mismatch ntawm tus kav hlau txais xov thiab SMA connector, coaxial cable splice poob, soldering teebmeem, thiab qhov sib thooj ntawm ntau yam khoom siv hluav taws xob rau kev sim teeb.
Daim duab 20 piav qhia txog kev tsim thiab kev ua kom zoo ntawm cov kav hlau txais xov hais hauv daim duab thaiv. Daim duab thaiv no muab cov lus piav qhia ib ntus ntawm cov qauv tsim MIMO kav hlau txais xov, nrog rau cov ntsiab lus uas ua lub luag haujlwm tseem ceeb hauv kev ua kom zoo dua tus kav hlau txais xov kom ua tiav qhov yuav tsum tau nce siab thiab kev sib cais siab dhau ntawm kev khiav hauj lwm ntau zaus.
Qhov ze-tsav MIMO kav hlau txais xov ntsuas tau ntsuas hauv SATIMO Near-Field Experimental Ib puag ncig ntawm UKM SATIMO Near-Field Systems Laboratory. Daim duab 21a, b piav qhia txog qhov simulated thiab pom E-dav hlau thiab H-dav hlau hluav taws xob cov qauv ntawm cov kav hlau txais xov MIMO uas tau thov nrog thiab tsis muaj MS ntawm kev khiav hauj lwm zaus ntawm 5.5 GHz. Nyob rau hauv kev khiav hauj lwm zaus ntawm 5.5 GHz, tus tsim tsis-MS MIMO kav hlau txais xov muab ib tug zoo ib yam bidirectional hluav taws xob qauv nrog rau sab lobe qhov tseem ceeb. Tom qab siv lub MS reflector, tus kav hlau txais xov muab cov qauv hluav taws xob unidirectional thiab txo cov theem ntawm lub nraub qaum, raws li pom hauv daim duab 21a, b. Nws yog ib nqi sau cia hais tias los ntawm kev siv ib tug metasurface nrog ib tug tooj liab backplane, lub tswv yim MIMO kav hlau txais xov qauv yog ruaj khov thiab unidirectional dua tsis muaj MS, nrog tsawg heev rov qab thiab sab lobes. Lub tswv yim MM array reflector txo lub nraub qaum thiab sab lobes ntawm tus kav hlau txais xov thiab kuj txhim kho cov yam ntxwv ntawm hluav taws xob los ntawm kev coj cov tam sim no nyob rau hauv ib qho kev taw qhia unidirectional (Fig. 21a, b), yog li ua kom nce thiab ncaj qha. Cov qauv ntsuas hluav taws xob tau txais rau qhov chaw nres nkoj 1 nrog 50 ohm load txuas nrog cov chaw nres nkoj ntxiv. Nws tau pom tias qhov kev sim ntsuas hluav taws xob yuav luag zoo ib yam li qhov simulated los ntawm CST, txawm hais tias muaj qee qhov sib txawv vim qhov tsis zoo ntawm cov khoom siv, kev cuam tshuam los ntawm cov chaw nres nkoj davhlau ya nyob twg, thiab poob hauv kev sib txuas cable. Tsis tas li ntawd, ib lub nylon spacer tau muab tso rau ntawm lub kav hlau txais xov thiab MS reflector, uas yog lwm qhov teeb meem cuam tshuam rau cov txiaj ntsig tau pom zoo piv rau cov txiaj ntsig tau kwv yees.
Cov qauv hluav taws xob ntawm tus tsim MIMO kav hlau txais xov (tsis muaj MS thiab nrog MS) ntawm qhov zaus ntawm 5.5 GHz tau simulated thiab sim.
Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias kev sib cais chaw nres nkoj thiab nws cov yam ntxwv cuam tshuam yog qhov tseem ceeb thaum ntsuas kev ua haujlwm ntawm MIMO systems. Kev ua tau zoo ntawm kev sib txawv ntawm MIMO qhov system, suav nrog lub hnab ntawv sib txuas coefficient (ECC) thiab ntau haiv neeg nce (DG), raug tshuaj xyuas los qhia txog qhov muaj zog ntawm MIMO kav hlau txais xov. ECC thiab DG ntawm MIMO kav hlau txais xov tuaj yeem siv los ntsuas nws qhov kev ua tau zoo vim tias lawv yog qhov tseem ceeb ntawm kev ua haujlwm ntawm MIMO system. Cov ntu hauv qab no yuav nthuav dav cov yam ntxwv ntawm MIMO tus kav hlau txais xov.
Lub hnab ntawv Correlation Coefficient (ECC). Thaum txiav txim siab ib qho MIMO system, ECC txiav txim siab txog qib uas cov ntsiab lus muaj feem cuam tshuam nrog ib leeg txog lawv cov khoom tshwj xeeb. Yog li, ECC qhia txog qib ntawm kev sib cais channel hauv kev sib txuas lus wireless. Lub ECC (lub hnab ntawv sib txuas coefficient) ntawm MIMO system tsim tuaj yeem txiav txim siab raws li S-tsis txwv thiab kev tawm mus deb. Los ntawm Eq. (7) thiab (8) ECC ntawm qhov kev thov MIMO kav hlau txais xov 31 tuaj yeem txiav txim siab.
Qhov kev xav coefficient yog sawv cev los ntawm Sii thiab Sij sawv cev rau kev sib kis coefficient. Cov qauv hluav taws xob peb-dimensional ntawm cov kav hlau txais xov j-th thiab i-th yog muab los ntawm cov kab lus \(\vec{R}_{j} \left( {\theta ,\varphi } \right)\) thiab \( \vec {{R_{i } }} Lub kaum sab xis uas sawv cev los ntawm \left( {\theta ,\varphi } \right)\) and \({\Omega }\). ECC nkhaus ntawm cov kav hlau txais xov tau pom zoo nyob rau hauv daim duab 22a thiab nws tus nqi tsawg dua 0.004, uas yog qhov zoo hauv qab tus nqi ntawm 0.5 rau lub wireless system. Yog li ntawd, qhov txo qis ECC tus nqi txhais tau hais tias qhov kev thov 4-chaw nres nkoj MIMO system muab kev sib txawv zoo tshaj 43.
Diversity Gain (DG) DG yog lwm qhov MIMO qhov kev ntsuas kev ua tau zoo uas piav qhia txog kev sib txawv li cas cuam tshuam rau lub zog hluav taws xob. Kev sib raug zoo (9) txiav txim siab DG ntawm MIMO kav hlau txais xov tau tsim, raws li tau piav qhia hauv 31.
Daim duab 22b qhia DG daim duab ntawm qhov kev thov MIMO, qhov twg tus nqi DG yog ze rau 10 dB. DG qhov tseem ceeb ntawm tag nrho cov kav hlau txais xov ntawm qhov tsim MIMO system tshaj 9.98 dB.
Table 1 piv cov lus thov metasurface MIMO kav hlau txais xov nrog tsis ntev los no tsim cov tshuab MIMO zoo sib xws. Qhov kev sib piv yuav siv rau hauv ntau yam kev ua tau zoo, suav nrog bandwidth, nce, kev sib cais siab tshaj plaws, kev ua tau zoo tag nrho, thiab kev ua tau zoo sib txawv. Cov kws tshawb fawb tau nthuav tawm ntau yam MIMO kav hlau txais xov prototypes nrog kev nce thiab kev sib cais txhim khu kev qha hauv 5, 44, 45, 46, 47. Piv nrog rau cov ntawv tshaj tawm yav dhau los, qhov kev thov MIMO system nrog metasurface reflectors outperforms lawv nyob rau hauv cov nqe lus ntawm bandwidth, nce, thiab kev sib cais. Tsis tas li ntawd, piv rau cov kav hlau txais xov zoo sib xws, qhov tsim MIMO system nthuav tawm cov kev ua tau zoo ntawm ntau haiv neeg thiab kev ua haujlwm tag nrho ntawm qhov me me. Txawm hais tias cov kav hlau txais xov tau piav qhia hauv Tshooj 5.46 muaj kev sib cais ntau dua li peb cov kav hlau txais xov, cov kav hlau txais xov no raug kev txom nyem los ntawm qhov loj me, nce qis, nqaim bandwidth, thiab kev ua haujlwm tsis zoo MIMO. 4-chaw nres nkoj MIMO kav hlau txais xov tau npaj siab hauv 45 nthuav qhia kev nce siab thiab ua haujlwm tau zoo, tab sis nws cov qauv tsim muaj kev sib cais tsawg, qhov loj me, thiab kev ua haujlwm tsis zoo. Ntawm qhov tod tes, cov kav hlau txais xov me me uas tau npaj tseg hauv 47 muaj qhov nce qis heev thiab kev ua haujlwm bandwidth, thaum peb tau thov MS raws li 4-chaw nres nkoj MIMO system nthuav tawm qhov me me, nce siab, kev sib cais siab thiab kev ua tau zoo MIMO. Yog li, lub tswv yim metasurface MIMO kav hlau txais xov tuaj yeem dhau los ua tus neeg sib tw loj rau sub-6 GHz 5G kev sib txuas lus.
Plaub-chaw nres nkoj metasurface reflector-raws li wideband MIMO kav hlau txais xov nrog kev nce siab thiab kev sib cais yog npaj los txhawb 5G daim ntawv thov hauv qab 6 GHz. Cov kab microstrip pub ib square radiating seem, uas yog truncated los ntawm ib tug square ntawm kab pheeb ces kaum. Cov lus thov MS thiab kav hlau txais xov emitter yog siv los ntawm cov khoom siv substrate zoo ib yam li Rogers RT5880 kom ua tiav kev ua tau zoo hauv kev sib txuas lus siab 5G. MIMO kav hlau txais xov nta ntau yam thiab nce siab, thiab muab kev sib cais suab ntawm MIMO Cheebtsam thiab kev ua haujlwm zoo heev. Tus tsim ib lub kav hlau txais xov muaj qhov me me ntawm 0.58?0.58?0.02? nrog 5 × 5 metasurface array, muab qhov dav 4.56 GHz kev khiav hauj lwm bandwidth, 8 dBi ncov nce thiab superior ntsuas efficiency. Lub tswv yim plaub-chaw nres nkoj MIMO kav hlau txais xov (2 × 2 array) yog tsim los ntawm orthogonally aligning txhua lub tswv yim ib lub kav hlau txais xov nrog lwm tus kav hlau txais xov nrog qhov ntev ntawm 1.05λ × 1.05λ × 0.02λ. Nws raug nquahu kom sib sau ua ke 10 × 10 MM array hauv qab 12 hli siab MIMO kav hlau txais xov, uas tuaj yeem txo cov hluav taws xob rov qab thiab txo qis kev sib txuas ntawm MIMO cov khoom, yog li txhim kho qhov nce thiab kev sib cais. Kev sim thiab simulation cov txiaj ntsig qhia tau tias MIMO tus qauv tsim tuaj yeem ua haujlwm nyob rau hauv ntau zaus ntawm 3.08-7.75 GHz, npog 5G spectrum hauv qab 6 GHz. Tsis tas li ntawd, qhov kev thov MS-based MIMO kav hlau txais xov txhim kho nws qhov nce los ntawm 2.9 dBi, ua tiav qhov siab tshaj plaws ntawm 8.3 dBi, thiab muab kev sib cais zoo heev (> 15.5 dB) ntawm MIMO cov khoom, ua kom muaj txiaj ntsig ntawm MS. Tsis tas li ntawd, cov kav hlau txais xov MIMO tau pom zoo muaj qhov nruab nrab tag nrho kev ua tau zoo ntawm 82% thiab qhov nruab nrab ntawm cov ntsiab lus qis ntawm 22 hli. Lub kav hlau txais xov nthuav qhia MIMO kev ua tau zoo ntawm ntau haiv neeg suav nrog DG siab heev (dhau 9.98 dB), ECC qis heev (tsawg dua 0.004) thiab unidirectional hluav taws xob qauv. Cov txiaj ntsig ntsuas tau zoo ib yam li cov txiaj ntsig simulation. Cov yam ntxwv no tau lees tias qhov tsim plaub-chaw nres nkoj MIMO kav hlau txais xov tuaj yeem yog qhov kev xaiv siv tau rau 5G kev sib txuas lus hauv sub-6 GHz ntau zaus.
Cowin tuaj yeem muab 400-6000MHz wideband PCB kav hlau txais xov, thiab kev txhawb nqa los tsim cov kav hlau txais xov tshiab raws li qhov koj xav tau, thov hu rau peb yam tsis muaj kev cuam tshuam yog tias koj muaj lus thov.
Post lub sij hawm: Oct-10-2024