I. Nhanganyaya
Fractals zvinhu zvemasvomhu zvinoratidzira zvakangofanana zvimiro pazvikero zvakasiyana. Izvi zvinoreva kuti kana iwe ukaswededza mukati / kunze pane fractal chimiro, chimwe nechimwe chezvikamu zvayo zvinotaridzika zvakafanana kune yese; ndiko kuti, mapatani ejometri akafanana kana zvimiro zvinodzokorora pamatanho ekukudza akasiyana (ona mienzaniso yefractal muMufananidzo 1). Mafractals mazhinji ane maumbirwo akaomarara, akadzama, uye asina magumo akaoma kunzwisisa.
mufananidzo 1
Pfungwa yefractals yakaunzwa nenyanzvi yemasvomhu Benoit B. Mandelbrot kumakore ekuma1970, kunyangwe kwakabva fractal geometry inogona kurondwa kumashure kwekutanga basa remasvomhu akawanda, saCantor (1870), von Koch (1904), Sierpinski (1915). ), Julia (1918), Fatou (1926), uye Richardson (1953).
Benoit B. Mandelbrot akadzidza hukama huri pakati pefractals uye zvisikwa kuburikidza nekuunza marudzi matsva emafractals kuti atevedzere mamwe maitiro akaoma, akadai semiti, makomo, uye mahombekombe egungwa. Akagadzira izwi rekuti "fractal" kubva muchirevo chechiLatin "fractus", zvinoreva "kutyoka" kana "kutsemuka", kureva kuti inoumbwa nezvidimbu zvakatyoka kana zvisina kujairika, kurondedzera zvimiro zvejometri zvisina kurongeka uye zvakatsemuka zvisingagone kurongeka nedzechinyakare Euclidean geometry. Pamusoro pezvo, akagadzira masvomhu modhi uye algorithms ekugadzira uye kudzidza mafractals, izvo zvakaita kuti kusikwa kweiyo yakakurumbira Mandelbrot set, iyo ingangove yakakurumbira uye inotaridzika inonakidza chimiro chefractal ine yakaoma uye isingaperi inodzokorora mapatani (ona Mufananidzo 1d).
Basa raMandelbrot harina kungokanganisa masvomhu chete, asi zvakare rine mashandisirwo muzvikamu zvakasiyana sefizikisi, mifananidzo yemakomputa, biology, economics, uye art. Muchokwadi, nekuda kwekugona kwavo kuenzanisira uye kumiririra zvakaoma uye zvakangofanana zvimiro, mafractals ane akawanda mashandisirwo ekushandisa munzvimbo dzakasiyana siyana. Semuenzaniso, iwo akashandiswa zvakanyanya munzvimbo dzinotevera dzekushandisa, inova ingori mienzaniso mishoma yekushandiswa kwavo kwakakura:
1. Mapikicha ekombuta neanopopayidzwa, achigadzira nzvimbo dzemusikirwo dzechokwadi uye dzinooneka dzinoyevedza, miti, makore, uye maumbirwo;
2. Data compression tekinoroji kuderedza saizi yemafaira edhijitari;
3. Chifananidzo uye chiratidzo chekugadzirisa, kubvisa zvinhu kubva pamifananidzo, kuona maitiro, nekupa maitiro ekugadzirisa mufananidzo uye nzira dzekuvakazve;
4. Biology, inotsanangura kukura kwemiti uye kurongeka kwetsinga muuropi;
5. Antenna theory uye metamatadium, kugadzira compact/multi-band antennas uye innovative metasurfaces.
Parizvino, fractal geometry inoramba ichiwana kushandiswa kutsva uye hunyanzvi mune dzakasiyana sainzi, hunyanzvi uye tekinoroji dzidziso.
Mune tekinoroji yemagetsi (EM) tekinoroji, zvimiro zvefractal zvinobatsira zvakanyanya kune zvikumbiro zvinoda miniaturization, kubva kumaantenna kuenda kune metamatadium uye frequency yakasarudzika nzvimbo (FSS). Kushandisa fractal geometry mune akajairwa antennas anogona kuwedzera iwo emagetsi kureba, nekudaro kuderedza saizi yese yeiyo resonant chimiro. Uye zvakare, iyo yekuzvifananidza yemhando yefractal maumbirwo inoita kuti ive yakanaka yekuziva akawanda-bhendi kana Broadband resonant zvimiro. Iwo echisikigo miniaturization masimba emafractals anonyanya kutaridzika pakugadzira maratidziro, akaganhurwa array antennas, metamaterial absorbers uye metasurfaces kune akasiyana maapplication. Muchokwadi, kushandisa zvidiki-diki zvakarongeka zvinhu zvinogona kuunza zvakati wandei, senge kudzikisira kuwirirana kana kukwanisa kushanda nearrays ane diki kwazvo element spacing, nokudaro kuve nechokwadi chekuita kwakanaka kwekuongorora uye mazinga epamusoro ekugadzikana kwemakona.
Nezvikonzero zvataurwa pamusoro apa, fractal antennas uye metasurfaces inomiririra nzvimbo mbiri dzinonakidza dzekutsvagisa mumunda wemagetsi emagetsi akakwezva kutariswa kwakawanda mumakore achangopfuura. Mafungiro ese ari maviri anopa akasarudzika nzira dzekushandisa nekudzora mafungu emagetsi, ane huwandu hwakasiyana hwemaapplication muwireless kutaurirana, radar masisitimu uye kunzwa. Zvimiro zvavo zvakada kufanana zvinovatendera kuti vadiki muhukuru vachichengetedza yakanakisa electromagnetic mhinduro. Uku compactness kunonyanya kubatsira munzvimbo-inomanikidzirwa maapplication, senge nharembozha, RFID tag, uye aerospace masisitimu.
Iko kushandiswa kwefractal antennas uye metasurfaces ine mukana wekuvandudza zvakanyanya waya isina waya, imaging, uye radar masisitimu, sezvo ivo vachigonesa compact, yepamusoro-inoshanda michina ine inowedzerwa mashandiro. Pamusoro pezvo, fractal geometry iri kuwedzera kushandiswa mukugadzira microwave sensors yekuongorora zvinhu, nekuda kwekugona kwayo kushanda mumabhendi akawanda e frequency uye kugona kwayo kuita miniaturized. Tsvagiridzo inoenderera mberi munzvimbo idzi inoenderera mberi nekuongorora magadzirirwo matsva, zvigadzirwa, uye matekiniki ekugadzira kuti vaone kugona kwavo kuzere.
Iri bepa rine chinangwa chekuongorora kutsvagisa uye kufambira mberi kwekushandiswa kwefractal antennas uye metasurfaces uye kuenzanisa iripo fractal-based antennas uye metasurfaces, ichiratidza zvakanakira uye zvinogumira. Chekupedzisira, ongororo yakazara yemagadzirirwo emagetsi uye metamaterial mauniti inoratidzwa, uye zvinonetsa uye mune ramangwana magadzirirwo emagetsi emagetsi zvimiro zvinokurukurwa.
2. FractalAntennaElements
Iyo yakajairika pfungwa yefractals inogona kushandiswa kugadzira exotic antenna zvinhu zvinopa kuita zvirinani pane zvakajairika antenna. Fractal antenna zvinhu zvinogona kunge zvakabatana muhukuru uye zvine akawanda-bhendi uye / kana Broadband kugona.
Dhizaini yefractal antennas inosanganisira kudzokorora chaiwo mapeteni ejometri pamakero akasiyana mukati meiyo antenna chimiro. Iyi yekuzvifananidza pateni inotitendera kuti tiwedzere hurefu hwese hweantenna mukati menzvimbo shoma yemuviri. Uye zvakare, fractal radiators inogona kuwana akawanda mabhendi nekuti zvikamu zvakasiyana zveantenna zvakafanana kune mumwe nemumwe pamakero akasiyana. Naizvozvo, fractal antenna zvinhu zvinogona kuve compact uye akawanda-bhendi, ichipa yakafara frequency yekuvhara kupfuura yakajairwa antenna.
Iyo pfungwa yefractal antennas inogona kuteverwa kumashure kusvika kuma1980s. Muna 1986, Kim naJaggard vakaratidza kushandiswa kwefractal kuzvifananidzira mune antenna array synthesis.
Muna 1988, nyanzvi yefizikisi Nathan Cohen akavaka antenna yekutanga pasirese fractal element. Akataura kuti nekubatanidza yega-yakafanana geometry muchimiro cheantenna, kuita kwayo uye kugona kweminiaturization kunogona kuvandudzwa. Muna 1995, Cohen akabatanidza Fractal Antenna Systems Inc., iyo yakatanga kupa nyika yekutanga kutengeserana fractal-based antenna mhinduro.
Pakati pe-1990s, Puente et al. yakaratidza kuwanda kwebhendi kugona kwefractals vachishandisa Sierpinski's monopole uye dipole.
Kubva basa raCohen naPuente, mabhenefiti epafractal antenna akakwezva kufarira kukuru kubva kune vaongorori uye mainjiniya mumunda wekufambiswa kwemashoko, zvichikonzera kuenderera mberi nekuongorora nekuvandudza tekinoroji yefractal antenna.
Nhasi, fractal antennas anoshandiswa zvakanyanya mumasevhisi ekutaurirana asina waya, kusanganisira nharembozha, Wi-Fi routers, uye satellite kutaurirana. Muchokwadi, fractal antenna idiki, yakawanda-bhendi, uye inoshanda zvakanyanya, ichiita kuti ive yakakodzera kune dzakasiyana siyana dzisina waya uye network.
Nhamba dzinotevera dzinoratidza mamwe fractal antennas akavakirwa pane anozivikanwa fractal maumbirwo, ayo angori mishoma mienzaniso yeakasiyana magadzirirwo anokurukurwa muzvinyorwa.
Kunyanya, Mufananidzo 2a unoratidza iyo Sierpinski monopole yakatsanangurwa muPuente, iyo inokwanisa kupa akawanda-bhendi kushanda. Gonyo yeSierpinski inoumbwa nekubvisa gonyo repakati rakapinduka kubva pahonyonhatu huru, sezviri kuratidzwa mumufananidzo 1b neMufananidzo 2a. Iyi nzira inosiya makona matatu akaenzana pachimiro, imwe neimwe iine kureba kwehafu yehafu yehonyo yekutanga (ona Mufananidzo 1b). Iyo imwe nzira yekubvisa inogona kudzokororwa kune matatu asara. Naizvozvo, chimwe nechimwe chezvikamu zvaro zvikuru zvitatu zvakanyatsoenzana nechinhu chose, asi muchikamu cheviri, zvichingodaro. Nekuda kwekufanana kwakakosha uku, Sierpinski inogona kupa akawanda ma frequency mabhendi nekuti zvikamu zvakasiyana zveantenna zvakafanana kune imwe neimwe pazvikero zvakasiyana. Sezvinoratidzwa muMufananidzo 2, iyo Sierpinski monopole yakarongwa inoshanda mumabhendi mashanu. Zvinogona kuonekwa kuti imwe neimwe yezvishanu-sub-gaskets (zvimiro zvedenderedzwa) muMufananidzo 2a ishanduro yakasimudzwa yechimiro chese, nokudaro ichipa zvishanu zvakasiyana-siyana zvekufambisa mabhendi, sezvinoratidzwa muchikamu chekuratidzira chekuisa muFigure 2b. Nhamba yacho inoratidzawo maparamendi ane chekuita nebhendi rega rega, kusanganisira frequency kukosha fn (1 ≤ n ≤ 5) pamutengo wakaderera wekuyerwa kwekudzoka kurasikirwa (Lr), iyo bandwidth bandwidth (Bwidth), uye frequency reshiyo pakati. mabhendi maviri ari pedyo (δ = fn +1/fn). Mufananidzo 2b unoratidza kuti mabhendi eSierpinski monopoles ane logarithmically nguva nenguva akapatsanurwa nechikamu che2 (δ ≅ 2), iyo inoenderana neiyo yakafanana scaling factor iripo mune zvakafanana zvimiro mune fractal shape.
mufananidzo 2
Mufananidzo 3a inoratidza diki refu waya antenna yakavakirwa paKoch fractal curve. Iyi antenna inokurudzirwa kuratidza maitiro ekushandisa nzvimbo-yekuzadza zvimiro zvefractal maumbirwo kugadzira madiki antenna. Muchokwadi, kudzikisa saizi yema antennas ndicho chinangwa chekupedzisira chenhamba huru yezvishandiso, kunyanya izvo zvinosanganisira nharembozha. Iyo Koch monopole inogadzirwa uchishandisa iyo fractal yekuvaka nzira inoratidzwa muFigure 3a. Iyo yekutanga iteration K0 ndeye monopole yakatwasuka. Iyo inotevera iteration K1 inowanikwa nekushandisa shanduko yakafanana kuK0, kusanganisira kuyera nechikamu chimwe chete patatu uye kutenderera ne0 °, 60 °, -60 °, uye 0 °, zvichiteerana. Iyi nzira inodzokororwa zvakare kuti uwane zvinhu zvinotevera Ki (2 ≤ i ≤ 5). Mufananidzo 3a unoratidza shanu-iteration version yeKoch monopole (kureva, K5) nehupamhi h yakaenzana ne 6 cm, asi urefu hwose hunopiwa nenzira l = h · (4/3) 5 = 25.3 cm. Antenna shanu dzinoenderana neshanu dzekutanga kudzokororwa kweKoch curve dzakaitika (ona Mufananidzo 3a). Zvose zviedzo uye data zvinoratidza kuti Koch fractal monopole inogona kuvandudza mashandiro echinyakare monopole (ona Mufananidzo 3b). Izvi zvinoratidza kuti zvinogona ku "miniaturize" fractal antennas, zvichivabvumira kuti vakwane mumavhoriyamu madiki uku vachichengetedza kuita kwakanaka.
mufananidzo 3
Mufananidzo 4a unoratidza fractal antenna yakavakirwa paCantor seti, iyo inoshandiswa kugadzira antenna yakakura yekushandiswa kwesimba kukohwa. Iyo yakasarudzika midziyo ye fractal antennas inosuma akawanda ari padyo resonances inoshandisirwa kupa yakakura bandwidth kupfuura yakajairwa antennas. Sezvinoratidzwa muMufananidzo 1a, kugadzirwa kweCantor fractal set iri nyore kwazvo: mutsara wekutanga wakarurama unokopwa uye wakakamurwa kuva zvikamu zvitatu zvakaenzana, izvo chikamu chepakati chinobviswa; nzira imwe chete inobva yashandiswa zvakare kune zvikamu zvitsva zvinogadzirwa. Iyo fractal iteration nhanho inodzokororwa kusvika antenna bandwidth (BW) ye0.8-2.2 GHz yawanikwa (kureva, 98% BW). Mufananidzo 4 unoratidza mufananidzo weiyo yakaitika antenna prototype (Mufananidzo 4a) uye yayo yekuisa inoratidzira coefficient (Mufananidzo 4b).
mufananidzo 4
Mufananidzo 5 unopa mimwe mienzaniso yefractal antennas, kusanganisira Hilbert curve-based monopole antenna, Mandelbrot-based microstrip patch antenna, uye Koch chitsuwa (kana "snowflake") fractal chigamba.
mufananidzo 5
Chekupedzisira, Mufananidzo 6 unoratidza akasiyana fractal kurongeka kwezvinhu array, kusanganisira Sierpinski carpet planar arrays, Cantor ring arrays, Cantor linear arrays, uye fractal miti. Aya marongero anobatsira pakugadzira sparse arrays uye/kana kuwana akawanda-bhendi kuita.
mufananidzo 6
Kuti udzidze zvakawanda nezve antennas, ndapota shanya:
Nguva yekutumira: Jul-26-2024
