Amakuru - Isuzuma rya Antena za Metamaterial Transmission Line

I. Intangiriro
Metamaterial ishobora gusobanurwa neza nk'imiterere yakozwe mu buryo bw'ubuhanga kugira ngo ikore imiterere imwe n'imwe ya electromagnetic idahari mu buryo bw'umwimerere. Metamaterial ifite permittivity negative na negative permeability yitwa lhm (Lhm). Lhm zakoreweho ubushakashatsi bwinshi mu miryango ya siyansi n'iy'ubuhanga. Mu 2003, LHM zashyizwe mu byiciro icumi bya mbere bya siyansi byo mu gihe cya none n'ikinyamakuru Science. Porogaramu nshya, ibitekerezo, n'ibikoresho byakozwe hifashishijwe imiterere yihariye ya LHM. Uburyo bwo kohereza (TL) ni uburyo bwiza bwo gushushanya bushobora no gusesengura amahame ya LHM. Ugereranyije na TL za gakondo, ikintu cy'ingenzi cyane kuri TL za metamaterial ni uburyo bwo kugenzura ibipimo bya TL (propagation constant) na impedance yihariye. Uburyo bwo kugenzura ibipimo bya TL bya metamaterial butanga ibitekerezo bishya byo gushushanya imiterere ya antene ifite ingano nto, imikorere myiza, n'imikorere mishya. Ishusho ya 1 (a), (b), na (c) igaragaza ingero za circuit zidafite igihombo z'umurongo wohereza w'iburyo (PRH), umurongo wohereza w'ibumoso (PLH), n'umurongo wohereza w'ibumoso uhuza iburyo n'ibumoso (CRLH), uko bikurikirana. Nkuko bigaragara ku Ishusho ya 1 (a), icyitegererezo cya circuit gihwanye na PRH TL ubusanzwe ni uruvange rw'ingufu z'uruhererekane n'ubushobozi bwa shunt. Nkuko bigaragara ku Ishusho ya 1 (b), icyitegererezo cya PLH TL ni uruvange rw'ingufu z'uruhererekane n'ubushobozi bwa shunt. Mu mikoreshereze ifatika, ntibishoboka gushyira mu bikorwa circuit ya PLH. Ibi biterwa n'ingaruka za parasitic series inductance n'ubushobozi bwa shunt. Kubwibyo, imiterere y'umurongo wohereza w'ibumoso ishobora kugaragara muri iki gihe ni imiterere yose ihuza ibumoso n'iburyo, nk'uko bigaragara ku Ishusho ya 1 (c).

Ishusho ya 1 Imiterere itandukanye y'urusobe rw'imirongo yo kohereza ubutumwa

Ingano ihoraho yo gukwirakwiza (γ) y'umurongo wo kohereza (TL) ibarwa muri ubu buryo: γ=α+jβ=Sqrt(ZY), aho Y na Z bahagarariye kwinjira n'impedance uko bikurikirana. Urebye CRLH-TL, Z na Y bishobora kugaragazwa muri ubu buryo:

CRLH TL imwe izaba ifite isano ikurikira yo gutatanya:

Ingano ya β ishobora kuba umubare nyawo cyangwa umubare wiyumvikanyweho. Niba β ari ukuri rwose mu rugero rw'impinduka, hari umurongo unyura mu rugero rw'impinduka bitewe na γ=jβ. Ku rundi ruhande, niba β ari umubare wiyumvikanyweho gusa mu rugero rw'impinduka, hari umurongo uhagarara mu rugero rw'impinduka bitewe na γ=α. Uyu murongo uhagarara ni uw'umwihariko kuri CRLH-TL kandi ntubaho muri PRH-TL cyangwa PLH-TL. Ishusho ya 2 (a), (b), na (c) yerekana imirongo inyuranamo (ni ukuvuga isano ya ω - β) ya PRH-TL, PLH-TL, na CRLH-TL, uko bikurikirana. Hashingiwe ku mirongo inyuranamo, umuvuduko w'itsinda (vg=∂ω/∂β) n'umuvuduko w'impinduka (vp=ω/β) by'umurongo ukwirakwiza amakuru ushobora guturukaho no kugereranywa. Kuri PRH-TL, bishobora kandi gusobanurwa uhereye ku murongo ko vg na vp bingana (ni ukuvuga, vpvg>0). Kuri PLH-TL, umurongo ugaragaza ko vg na vp bitangana (ni ukuvuga vpvg<0). Umurongo uhanamye wa CRLH-TL ugaragaza kandi ko akarere ka LH kabaho (ni ukuvuga vpvg <0) n'akarere ka RH (ni ukuvuga vpvg > 0). Nkuko bigaragara ku Ishusho ya 2(c), kuri CRLH-TL, niba γ ari umubare nyawo, hari umurongo uhagarara.

Ishusho ya 2 Imirongo itandukanye yo kohereza ubutumwa igana ahantu hatandukanye

Ubusanzwe, urukurikirane n'impinduka zihurirana bya CRLH-TL biratandukanye, byitwa imiterere idahuye. Ariko, iyo ingano y'urukurikirane n'impinduka zihurirana ari zimwe, byitwa imiterere ingana, kandi icyitegererezo cyoroheje cy'uruhererekane rw'amashanyarazi kigaragara ku Ishusho ya 3 (a).

Ishusho ya 3 Icyitegererezo cya Circuit n'umurongo uhuza umurongo uhuza ibumoso

Uko inshuro ziyongera, imiterere y'ikwirakwira rya CRLH-TL igenda yiyongera buhoro buhoro. Ibi biterwa nuko umuvuduko w'icyiciro (ni ukuvuga vp=ω/β) ugenda uterwa n'ikwirakwira ryabyo. Ku murongo muto, CRLH-TL iyoborwa na LH, mu gihe ku murongo munini, CRLH-TL iyoborwa na RH. Ibi bigaragaza imiterere ibiri ya CRLH-TL. Ishusho y'ikwirakwira rya CRLH-TL igaragara ku Ishusho ya 3 (b). Nkuko bigaragara ku Ishusho ya 3 (b), ihinduka kuva kuri LH ujya kuri RH riba kuri:

Aho ω0 ari inshuro y'impinduka. Kubwibyo, mu buryo buringaniye, impinduka nziza iva kuri LH ijya kuri RH kuko γ ari umubare w'ibitekerezo gusa. Kubwibyo, nta gice cyo guhagarara cy'ikwirakwizwa rya CRLH-TL riringaniye. Nubwo β ari zeru kuri ω0 (ugereranyije n'uburebure bw'umurambararo, ni ukuvuga, λg=2π/|β|), umuraba uracyakwirakwira kuko vg kuri ω0 atari zeru. Mu buryo nk'ubwo, kuri ω0, ihinduka ry'itsinda ni zeru kuri TL y'uburebure d (ni ukuvuga, φ= - βd=0). Iterambere ry'itsinda (ni ukuvuga, φ>0) riba mu cyiciro cya LH (ni ukuvuga, ω<ω0), naho isubira inyuma ry'itsinda (ni ukuvuga, φ<0) riba mu cyiciro cya RH (ni ukuvuga, ω>ω0). Kuri CRLH TL, impedance iranga isobanurwa gutya:

Aho ZL na ZR ari impedances za PLH na PRH, uko bikurikirana. Ku kibazo kidahuje, impedances ziranga zishingira ku nshuro. Ikigereranyo cyavuzwe haruguru kigaragaza ko ikibazo gishingiye ku nshuro kidahuje, bityo gishobora kugira bandwidth yagutse. Ikigereranyo cya TL cyavuye hejuru gisa n'ibipimo by'ibice bigena ibikoresho bya CRLH. Igipimo cyo gukwirakwiza cya TL ni γ=jβ=Sqrt(ZY). Bitewe n'igipimo cyo gukwirakwiza cy'ibikoresho (β=ω x Sqrt(εμ)), ikigereranyo gikurikira gishobora kuboneka:

Mu buryo nk'ubwo, impedance iranga TL, ni ukuvuga, Z0 = Sqrt (ZY), isa n'impedance iranga ibikoresho, ni ukuvuga, η = Sqrt (μ / ε), igaragazwa nka:

Igipimo cyo kugarura inyuma cya CRLH-TL kiringaniye kandi kitaringaniye (ni ukuvuga n = cβ/ω) kigaragara ku Ishusho ya 4. Ku Ishusho ya 4, igipimo cyo kugarura inyuma cya CRLH-TL mu rugero rwa LH ni negative naho igipimo cyo kugarura inyuma mu rugero rwa RH ni cyiza.

Igishushanyo cya 4 Ibipimo bisanzwe byo kugarura ubuziranenge bw'ibipimo bya CRLH TLs biringaniye n'ibitaringaniye.

1. Umuyoboro wa LC
Mu guca mu tunyangingo twa LC twa bandpass tugaragara ku Ishusho ya 5 (a), CRLH-TL isanzwe ifite uburebure bungana neza bwa d ishobora kubakwa buri gihe cyangwa idakorwa buri gihe. Muri rusange, kugira ngo byorohereze kubara no gukora CRLH-TL, urujya n'uruza rugomba kuba rumeze nk'uruza. Ugereranyije n'icyitegererezo cy'Ishusho ya 1 (c), akantu k'uruza kari ku Ishusho ya 5 (a) nta bunini gafite kandi uburebure bufatika ni buto cyane (ni ukuvuga Δz muri metero). Ukurikije uburebure bwako bw'amashanyarazi θ = Δφ (rad), igice cy'akantu k'uruza gashobora kugaragazwa. Ariko, kugira ngo hamenyekane neza inductance na capacitance ikoreshwa, hagomba gushyirwaho uburebure bufatika bwa p. Guhitamo ikoranabuhanga ryo gukoresha (nk'imikorostere, coplanar waveguide, ibice byo gushyira hejuru, nibindi) bizagira ingaruka ku bunini bufatika bwa kantu k'uruza gafite. Kantu k'uruza gafite uburebure bwa d ku Ishusho ya 5 (a) gisa n'icyitegererezo cy'inyongera cy'Ishusho ya 1 (c), kandi umupaka wacyo wa p = Δz → 0. Dukurikije imiterere y’ubumwe p → 0 mu Ishusho ya 5 (b), TL ishobora kubakwa (hakoreshejwe utunyangingo twa LC ducagagura) bingana na CRLH-TL ikwiriye ifite uburebure bwa d, ku buryo TL isa n’aho ihuye n’imiraba ya electromagnetic.

Ishusho ya 5 CRLH TL ishingiye ku muyoboro wa LC.

Ku ngirabuzimafatizo ya LC, ukurikije imiterere y'umupaka (PBCs) isa na theorem ya Bloch-Floquet, isano y'ikwirakwira ry'ngirabuzimafatizo ya LC iragaragazwa kandi ikagaragazwa ku buryo bukurikira:

Impedansi y'uruhererekane (Z) na shunt admittance (Y) by'akagari ka LC bigenwa n'ibipimo bikurikira:

Kubera ko uburebure bw'amashanyarazi bw'urukiramende rwa LC ari buke cyane, Taylor approximation ishobora gukoreshwa kugira ngo haboneke:

2. Gushyira mu bikorwa ibintu bifatika
Mu gice cyabanje, umuyoboro wa LC wo gukora CRLH-TL wavuzweho. Imiyoboro nk'iyo ya LC ishobora gukorwa gusa hakoreshejwe ibice bifatika bishobora gutanga ubushobozi bukenewe (CR na CL) na inductance (LR na LL). Mu myaka ya vuba aha, ikoreshwa ry'ibice bya chip bya SMT cyangwa ibice bya divide byakuruye abantu benshi. Microstrip, stripline, coplanar waveguide cyangwa izindi koranabuhanga zisa nazo zishobora gukoreshwa mu gukora ibice bya divide. Hari ibintu byinshi byo kuzirikana mu gihe uhitamo chip za SMT cyangwa ibice bya divide. Imiterere ya CRLH ishingiye kuri SMT irakunze gukoreshwa kandi yoroshye kuyishyira mu bikorwa mu bijyanye no gusesengura no gushushanya. Ibi biterwa n'uko hari ibice bya chip bya SMT bitari ku isoko, bidasaba kuvugururwa no gukorwa ugereranije n'ibice bya divide. Ariko, kuboneka kw'ibice bya SMT biratatanye, kandi akenshi bikora gusa ku murongo muto (ni ukuvuga, 3-6GHz). Kubwibyo, imiterere ya CRLH ishingiye kuri SMT ifite ingano nto y'imikorere n'imiterere yihariye y'icyiciro. Urugero, mu bikorwa byo gutanga urumuri, ibice bya chip bya SMT bishobora kudashoboka. Ishusho ya 6 igaragaza imiterere ikwirakwijwe ishingiye kuri CRLH-TL. Imiterere ikorwa hakoreshejwe imiyoboro ya capacitance interdigital na short-circuit, ikora series capacitance CL na parallel inductance LL ya LH. Capacitance iri hagati y'umurongo na GND ifatwa nk'aho ari RH capacitance CR, naho inductance ikomoka ku ruziga rwa magnetic flux rukorwa n'umuvuduko w'amashanyarazi mu miterere ya interdigital ifatwa nk'aho ari RH inductance LR.