Kav hlau txais xov tshuaj xyuas: Kev tshuaj xyuas ntawm Fractal Metasurfaces thiab kav hlau txais xov tsim

Lub tswv yim ntawm fractal tau qhia los ntawm mathematician Benoit B. Mandelbrot hauv xyoo 1970, txawm hais tias lub hauv paus pib ntawm fractal geometry tuaj yeem taug qab mus rau ntau tus lej ua ntej, xws li Cantor (1870), von Koch (1904), Sierpinski (1915). ), Julia (1918), Fatou (1926), thiab Richardson (1953).
Benoit B. Mandelbrot tau kawm txog kev sib raug zoo ntawm fractals thiab xwm los ntawm kev qhia cov tshiab fractals los simulate ntau cov qauv, xws li ntoo, roob, thiab ntug hiav txwv dej. Nws coined lo lus "fractal" los ntawm Latin adjective "fractus", lub ntsiab lus "pob" los yog "fractured", piv txwv li, muaj li ntawm tawg los yog irregular pieces, los piav qhia txog tsis xwm yeem thiab fragmented geometric duab uas tsis tau muab cais los ntawm cov tsoos Euclidean geometry. Tsis tas li ntawd, nws tau tsim cov qauv lej thiab cov txheej txheem rau kev tsim thiab kawm fractals, uas tau coj mus rau kev tsim cov Mandelbrot nto moo teeb, uas yog tej zaum lub npe nrov tshaj plaws thiab pom kev zoo nkauj fractal zoo nkauj nrog complex thiab infinitely rov ua qauv (saib daim duab 1d).
Mandelbrot txoj haujlwm tsis yog tsuas yog cuam tshuam rau kev ua lej, tab sis kuj muaj cov ntawv thov hauv ntau yam xws li physics, computer graphics, biology, economics, thiab kos duab. Qhov tseeb, vim lawv muaj peev xwm ua qauv thiab sawv cev rau cov qauv sib txawv thiab tus kheej zoo sib xws, fractals muaj ntau yam kev siv tshiab hauv ntau yam. Piv txwv li, lawv tau siv dav hauv cov ntawv thov hauv qab no, uas tsuas yog qee qhov piv txwv ntawm lawv daim ntawv thov dav:
1. Khoos phis tawj duab thiab cov yeeb yaj kiab, tsim kom muaj qhov tseeb thiab pom kev zoo nkauj zoo nkauj, ntoo, huab, thiab textures;
2. Cov ntaub ntawv compression tshuab kom txo qhov loj ntawm cov ntaub ntawv digital;
3. Cov duab thiab cov teeb liab ua, rho tawm cov yam ntxwv ntawm cov duab, kuaj cov qauv, thiab muab cov duab zoo compression thiab kev tsim kho dua tshiab;
4. Biology, piav txog kev loj hlob ntawm cov nroj tsuag thiab lub koom haum ntawm neurons nyob rau hauv lub hlwb;
5. Kav hlau txais xov txoj kev xav thiab metamaterials, tsim compact/multi-band antennas thiab lub metasurfaces tshiab.
Tam sim no, fractal geometry tseem nrhiav kev siv tshiab thiab tshiab hauv ntau yam kev tshawb fawb, kos duab thiab thev naus laus zis.
Hauv tshuab electromagnetic (EM), cov duab fractal muaj txiaj ntsig zoo rau cov ntawv thov uas yuav tsum tau siv me me, los ntawm cov kav hlau txais xov mus rau cov khoom siv thiab cov khoom siv ntau zaus (FSS). Siv fractal geometry nyob rau hauv cov pa kav hlau txais xov tuaj yeem ua rau lawv cov hluav taws xob ntev, yog li txo qhov loj me ntawm cov qauv resonant. Tsis tas li ntawd, nws tus kheej zoo ib yam ntawm cov duab fractal ua rau lawv zoo tagnrho rau kev paub txog ntau pawg lossis broadband resonant qauv. Lub peev xwm ntawm miniaturization ntawm fractals yog tshwj xeeb tshaj yog txaus nyiam rau kev tsim cov reflectarrays, phased array antennas, metamaterial absorbers thiab metasurfaces rau ntau yam kev siv. Qhov tseeb, siv cov ntsiab lus me me tuaj yeem nqa tau ntau yam zoo, xws li txo kev sib koom ua ke los yog muaj peev xwm ua haujlwm nrog arrays nrog cov ntsiab lus me me, yog li ua kom ntseeg tau zoo scanning kev ua tau zoo thiab qib siab dua ntawm kev ruaj ntseg angular.
Rau cov laj thawj uas tau hais los saum toj no, fractal kav hlau txais xov thiab metasurfaces sawv cev rau ob qhov kev tshawb fawb zoo hauv thaj chaw ntawm electromagnetics uas tau nyiam ntau yam hauv xyoo tas los no. Ob lub tswv yim muab cov kev tshwj xeeb los tswj thiab tswj cov hluav taws xob tsis sib xws, nrog rau ntau yam kev siv hauv kev sib txuas lus wireless, radar systems thiab sensing. Lawv cov khoom zoo sib xws tso cai rau lawv me me thaum tswj xyuas cov lus teb electromagnetic zoo. Qhov no compactness yog tshwj xeeb tshaj yog zoo nyob rau hauv qhov chaw-constrained daim ntaub ntawv, xws li mobile pab kiag li lawm, RFID cim npe, thiab aerospace systems.
Kev siv cov kav hlau txais xov fractal thiab metasurfaces muaj peev xwm txhim kho kev sib txuas lus wireless, duab, thiab radar systems, vim tias lawv ua kom cov khoom siv compact, ua haujlwm siab nrog kev ua haujlwm zoo dua. Tsis tas li ntawd, fractal geometry yog nce siv nyob rau hauv kev tsim ntawm microwave sensors rau cov ntaub ntawv kuaj mob, vim nws muaj peev xwm mus ua hauj lwm nyob rau hauv ntau zaus bands thiab nws muaj peev xwm yuav miniaturized. Kev tshawb fawb tsis tu ncua hauv cov cheeb tsam no txuas ntxiv tshawb nrhiav cov qauv tshiab, cov ntaub ntawv, thiab cov txheej txheem tsim kom paub txog lawv lub peev xwm tag nrho.
Daim ntawv no yog tsom los tshuaj xyuas cov kev tshawb fawb thiab kev ua tiav ntawm fractal antennas thiab metasurfaces thiab sib piv cov fractal-based antennas thiab metasurfaces uas twb muaj lawm, qhia txog lawv qhov zoo thiab kev txwv. Thaum kawg, ib qho kev ntsuam xyuas dav dav ntawm cov khoom siv hluav taws xob tshiab thiab cov khoom siv hluav taws xob tau nthuav tawm, thiab cov kev sib tw thiab kev txhim kho yav tom ntej ntawm cov qauv hluav taws xob electromagnetic tau tham txog.