Labarai - Bita na eriya ta watsawa dangane da kayan aiki (Sashe na 2)

2. Aikace-aikacen MTM-TL a cikin Tsarin Antenna
Wannan sashe zai mayar da hankali kan TLs metamaterial na wucin gadi da wasu aikace-aikacen gama gari da suka dace don fahimtar tsarin eriya daban-daban tare da ƙarancin farashi, masana'anta mai sauƙi, ƙarami, faffadan bandwidth, babban riba da inganci, iyawar sikanin kewayon da ƙarancin martaba. An tattauna su a kasa.

1. Broadband da eriya masu yawa
A cikin TL na yau da kullun tare da tsayin l, lokacin da aka ba da mitar angular ω0, ana iya ƙididdige tsawon lantarki (ko lokaci) na layin watsawa kamar haka:

Inda vp ke wakiltar saurin saurin layin watsawa. Kamar yadda ake iya gani daga sama, bandwidth yayi daidai da jinkirin rukuni, wanda shine abin da aka samu na φ game da mita. Saboda haka, yayin da tsawon layin watsawa ya zama guntu, bandwidth kuma ya zama fadi. A wasu kalmomi, akwai dangantaka mai mahimmanci tsakanin bandwidth da mahimmancin lokaci na layin watsawa, wanda ke da ƙira ta musamman. Wannan yana nuna cewa a cikin da'irori da aka rarraba na gargajiya, bandwidth mai aiki ba shi da sauƙin sarrafawa. Ana iya danganta wannan ga iyakancewar layin watsawa na gargajiya dangane da matakan 'yanci. Koyaya, abubuwan lodi suna ba da damar ƙarin sigogi da za a yi amfani da su a cikin TLs na metamaterial, kuma ana iya sarrafa martanin lokaci zuwa wani ɗan lokaci. Don ƙara yawan bandwidth, wajibi ne a sami irin wannan gangara kusa da mitar aiki na halayen watsawa. Metamaterial na wucin gadi TL na iya cimma wannan burin. Dangane da wannan hanyar, ana ba da shawarar hanyoyin da yawa don haɓaka bandwidth na eriya a cikin takarda. Masana sun ƙirƙira kuma sun ƙirƙira eriya mai watsa labarai guda biyu masu ɗauke da rabe-raben resonators na zobe (duba Hoto na 7). Sakamakon da aka nuna a cikin hoto na 7 ya nuna cewa bayan loda resonator na tsagawar zobe tare da eriyar monopole na al'ada, yanayin mitar ƙaramar ƙaranci yana jin daɗi. An inganta girman girman resonator na zobe don cimma daidaito kusa da na eriyar monopole. Sakamakon ya nuna cewa lokacin da ra'ayoyin biyu suka zo daidai, ƙimar bandwidth da halayen eriya suna ƙaruwa. Tsawon da nisa na eriyar monopole sune 0.25λ0 × 0.11λ0 da 0.25λ0 × 0.21λ0 (4GHz), bi da bi, kuma tsayin da faɗin eriyar monopole wanda aka ɗora tare da tsagawar zobe shine 0.29λ0 × 0.21λ0 (2.9GHz) ), bi da bi. Don eriyar F-dimbin yawa na al'ada da eriya mai siffa T ba tare da tsagawar zobe ba, mafi girman riba da ingancin radiation da aka auna a cikin rukunin 5GHz sune 3.6dBi - 78.5% da 3.9dBi - 80.2%, bi da bi. Don eriya da aka ɗora tare da resonator mai tsaga, waɗannan sigogi sune 4dBi - 81.2% da 4.4dBi - 83%, bi da bi, a cikin rukunin 6GHz. Ta hanyar aiwatar da resonator mai tsagawa azaman nauyin da ya dace akan eriyar monopole, ana iya tallafawa nau'ikan 2.9GHz ~ 6.41GHz da 2.6GHz ~ 6.6GHz, daidai da ƙananan bandwidths na 75.4% da ~ 87%, bi da bi. Wadannan sakamakon sun nuna cewa an inganta ma'aunin bandwidth da kusan sau 2.4 da sau 2.11 idan aka kwatanta da eriya ta monopole na gargajiya na kusan tsayayyen girman.

Hoto 7. Eriya mai watsa labarai guda biyu masu ɗauke da resonators mai raba zobe.

Kamar yadda aka nuna a hoto na 8, ana nuna sakamakon gwaji na ƙaramin eriyar monopole da aka buga. Lokacin da S11≤- 10 dB, bandwidth mai aiki shine 185% (0.115-2.90 GHz), kuma a 1.45 GHz, ƙimar kololuwa da ingancin radiation shine 2.35 dBi da 78.8%, bi da bi. Tsarin eriya yayi kama da tsarin takarda triangular baya-da-baya, wanda ake ciyar da shi ta hanyar rarraba wutar lantarki mai curvilinear. GND ɗin da aka yanke ya ƙunshi kututture na tsakiya da aka sanya a ƙarƙashin mai ciyarwa, kuma an rarraba zobe masu buɗewa guda huɗu kewaye da shi, wanda ke faɗaɗa bandwidth na eriya. Eriya tana haskaka kusan ko'ina, tana rufe mafi yawan maƙallan VHF da S, da duk rukunin UHF da L. Girman jiki na eriya shine 48.32 × 43.72 × 0.8 mm3, kuma girman wutar lantarki shine 0.235λ0 × 0.211λ0 × 0.003λ0. Yana da fa'idodi na ƙananan girma da ƙarancin farashi, kuma yana da yuwuwar aikace-aikacen aikace-aikacen a cikin tsarin sadarwa mara igiyar waya.

Hoto 8: Eriya ta monopole maɗaukaka mai tsagawar zobe.

Hoto na 9 yana nuna tsarin eriya mai tsari wanda ya ƙunshi nau'i-nau'i biyu na madaukai na madaidaicin waya masu haɗin kai wanda aka yi ƙasa zuwa wani jirgin ƙasa mai siffar T-runcated ta hanyoyi biyu. Girman eriya shine 38.5 × 36.6 mm2 (0.070λ0 × 0.067λ0), inda λ0 shine tsayin sarari kyauta na 0.55 GHz. Eriya tana haskakawa ko'ina a cikin E-jirgin sama a cikin rukunin mitar aiki na 0.55 ~ 3.85 GHz, tare da matsakaicin riba na 5.5dBi a 2.35GHz da ingantaccen 90.1%. Waɗannan fasalulluka sun sa eriyar da aka tsara ta dace da aikace-aikace daban-daban, gami da UHF RFID, GSM 900, GPS, KPCS, DCS, IMT-2000, WiMAX, WiFi da Bluetooth.

Hoto 9 Tsarin eriya da aka tsara.

2. Leaky Wave Eriya (LWA)
Sabuwar eriyar raƙuman ruwa tana ɗaya daga cikin manyan aikace-aikace don gane TL metamaterial na wucin gadi. Don eriya masu leaky, tasirin β akai-akai akan kusurwar radiyo (θm) da matsakaicin girman katako (Δθ) shine kamar haka:

L shine tsayin eriya, k0 shine lambar igiyar ruwa a sarari kyauta, kuma λ0 shine tsayin raƙuman ruwa a sarari kyauta. Lura cewa radiation yana faruwa ne kawai lokacin da |β|

3. eriya mai resonator na sifili
Keɓaɓɓen kadarorin CRLH metamaterial shine β na iya zama 0 lokacin da mitar ba ta kai sifili ba. Dangane da wannan kadara, ana iya samar da sabon sifili mai resonator (ZOR). Lokacin da β ya zama sifili, babu motsin lokaci da ke faruwa a cikin gabaɗayan resonator. Wannan shi ne saboda canjin lokaci akai-akai φ = - βd = 0. Bugu da ƙari, resonance ya dogara ne kawai akan nauyin mai amsawa kuma yana da zaman kanta daga tsawon tsarin. Hoto na 10 yana nuna cewa an ƙirƙira eriyar da aka tsara ta hanyar amfani da raka'a biyu da uku tare da siffar E, kuma jimlar girman ita ce 0.017λ0 × 0.006λ0 × 0.001λ0 da 0.028λ0 × 0.008λ0 × 0.001λ0 × 0.001λ0, bi da bi, inda λ0th, bi da bi. na sarari kyauta a aiki mitoci na 500 MHz da 650 MHz, bi da bi. Eriya tana aiki a mitoci na 0.5-1.35 GHz (0.85 GHz) da 0.65-1.85 GHz (1.2 GHz), tare da bandwidth dangi na 91.9% da 96.0%. Baya ga halaye na ƙananan girman da faffadan bandwidth, riba da ingancin eriya ta farko da ta biyu sune 5.3dBi da 85% (1GHz) da 5.7dBi da 90% (1.4GHz), bi da bi.

Hoto 10 Tsarin eriya mai sau biyu-E da sau uku-E.

4. Ramin Eriya
An ba da shawarar hanya mai sauƙi don faɗaɗa buɗewar eriyar CRLH-MTM, amma girman eriyar ta kusan baya canzawa. Kamar yadda aka nuna a hoto na 11, eriya ta ƙunshi raka'o'in CRLH da aka jera a tsaye akan junansu, waɗanda ke ɗauke da faci da layukan maƙasudi, kuma akwai ramin S-dimbin yawa akan facin. Ana ciyar da eriya ta hanyar CPW da ta dace, kuma girmansa shine 17.5 mm × 32.15 mm × 1.6 mm, daidai da 0.204λ0 × 0.375λ0 × 0.018λ0, inda λ0 (3.5GHz) ke wakiltar tsayin daka na sarari kyauta. Sakamakon ya nuna cewa eriya tana aiki a cikin mitar mitar 0.85-7.90GHz, kuma bandwidth na aiki shine 161.14%. Mafi girman riba da ingancin eriya suna bayyana a 3.5GHz, waɗanda ke 5.12dBi da ~ 80%, bi da bi.