Kapangidwe ka Antena-Rectifier
Khalidwe la ma rectenna otsatira EG topology mu Chithunzi 2 ndilakuti antenna imagwirizana mwachindunji ndi rectifier, osati muyezo wa 50Ω, zomwe zimafuna kuchepetsa kapena kuchotsa dera lofananira kuti lipatse mphamvu rectifier. Gawoli likuwunikanso zabwino za ma rectenna a SoA okhala ndi ma antenna ndi ma rectenna osakhala a 50Ω opanda ma network ofanana.
1. Ma Antena Ang'onoang'ono Ogwiritsa Ntchito Magetsi
Ma antenna a LC resonant ring akhala akugwiritsidwa ntchito kwambiri m'mapulogalamu omwe kukula kwa makina ndikofunikira kwambiri. Pafupipafupi pansi pa 1 GHz, kutalika kwa mafunde kungapangitse ma antenna ogawa zinthu wamba kukhala ndi malo ambiri kuposa kukula konse kwa makinawo, ndipo mapulogalamu monga ma transceiver ophatikizidwa kwathunthu a ma implants amthupi amapindula makamaka ndi kugwiritsa ntchito ma antenna ang'onoang'ono amagetsi a WPT.
Kupindika kwakukulu kwa antenna yaying'ono (pafupi ndi resonance) kungagwiritsidwe ntchito kuphatikiza mwachindunji chosinthira kapena ndi netiweki yowonjezera ya on-chip capacitive matching. Ma antenna ang'onoang'ono amagetsi anenedwa mu WPT ndi LP ndi CP pansi pa 1 GHz pogwiritsa ntchito ma antenna a Huygens dipole, okhala ndi ka=0.645, pomwe ka=5.91 mu ma dipole wamba (ka=2πr/λ0).
2. Antena yolumikizira chosinthira chosinthira
Impedance yodziwika bwino ya diode imakhala ndi capacitive kwambiri, kotero antenna yopangira imafunika kuti pakhale conjugate impedance. Chifukwa cha capacitive impedance ya chip, ma antenna opangira impedance apamwamba akhala akugwiritsidwa ntchito kwambiri mu ma RFID tag. Ma antenna a dipole posachedwapa akhala chizolowezi cha ma antenna ovuta a RFID impedance, omwe amasonyeza impedance yayikulu (kukana ndi reactance) pafupi ndi ma resonant frequency awo.
Ma antenna a dipole opangidwa ndi inductive agwiritsidwa ntchito kuti agwirizane ndi mphamvu yayikulu ya rectifier mu frequency band yosangalatsa. Mu antenna ya dipole yopindidwa, mzere waufupi wawiri (dipole folding) umagwira ntchito ngati transformer ya impedance, zomwe zimathandiza kupanga antenna ya impedance yapamwamba kwambiri. Kapenanso, kudya kwa bias kumayambitsa kuchulukitsa inductive reactance komanso impedance yeniyeni. Kuphatikiza zinthu zambiri za dipole zosankhidwa ndi unbalanced bow-tie radial stubs kumapanga dual broadband high impedance antenna. Chithunzi 4 chikuwonetsa ma antenna ena omwe amanenedwa kuti ndi rectifier conjugate.
Chithunzi 4
Makhalidwe a radiation mu RFEH ndi WPT
Mu chitsanzo cha Friis, mphamvu ya PRX yolandiridwa ndi antenna patali d kuchokera ku chotumizira ndi ntchito yolunjika ya wolandila ndi wotumiza (GRX, GTX).
Kuwongolera kwakukulu kwa lobe ya antenna ndi polarization zimakhudza mwachindunji kuchuluka kwa mphamvu zomwe zasonkhanitsidwa kuchokera ku mafunde a incident. Makhalidwe a ma radiation a antenna ndi magawo ofunikira omwe amasiyanitsa pakati pa RFEH yozungulira ndi WPT (Chithunzi 5). Ngakhale kuti mu ntchito zonse ziwiri, njira yofalitsira ikhoza kusadziwika ndipo zotsatira zake pa mafunde olandiridwa ziyenera kuganiziridwa, chidziwitso cha antenna yotumizira chingagwiritsidwe ntchito. Gome 3 likuwonetsa magawo ofunikira omwe afotokozedwa mu gawoli ndi momwe amagwiritsidwira ntchito pa RFEH ndi WPT.
Chithunzi 5
1. Malangizo ndi Kupindula
Mu ntchito zambiri za RFEH ndi WPT, zimaganiziridwa kuti chosonkhanitsa sichidziwa komwe kuwala kwa ngozi kumachitika ndipo palibe njira yowonera (LoS). Mu ntchitoyi, mapangidwe ndi malo angapo a antenna afufuzidwa kuti awonjezere mphamvu yolandiridwa kuchokera ku gwero losadziwika, losadalira kulumikizana kwa lobe yayikulu pakati pa chotumizira ndi cholandirira.
Ma antenna ozungulira onse akhala akugwiritsidwa ntchito kwambiri mu ma rectenna a RFEH ozungulira chilengedwe. M'mabuku, PSD imasiyana malinga ndi momwe antenna imayendera. Komabe, kusiyana kwa mphamvu sikunafotokozedwe, kotero sizingatheke kudziwa ngati kusinthaku kumachitika chifukwa cha mawonekedwe a radiation a antenna kapena chifukwa cha kusalingana kwa polarization.
Kuwonjezera pa ntchito za RFEH, ma antenna ndi ma arrays okhala ndi ma high-gain directional akhala akunenedwa kwambiri za microwave WPT kuti awonjezere mphamvu yosonkhanitsa mphamvu ya RF yochepa kapena kuthetsa kutayika kwa kufalikira. Ma Yagi-Uda rectenna arrays, ma bowtie arrays, ma spiral arrays, ma tightly combined Vivaldi arrays, ma CPW CP arrays, ndi ma patch arrays ndi ena mwa ma scalable rectenna implementations omwe angapangitse kuti mphamvu ya incident ichuluke kwambiri pansi pa dera linalake. Njira zina zowonjezerera antenna gain zikuphatikizapo substrate integrated waveguide (SIW) technology mu ma microwave ndi ma millimeter wave bands, apadera ku WPT. Komabe, ma high-gain rectenna amadziwika ndi ma beammbits ochepa, zomwe zimapangitsa kuti kulandira mafunde m'njira zosiyanasiyana kusagwire ntchito bwino. Kafukufuku wokhudza kuchuluka kwa zinthu za antenna ndi ma ports adatsimikiza kuti ma high-gain directional directivity sakugwirizana ndi mphamvu yochuluka yokolola mu ambient RFEH poganiza kuti pali zinthu zitatu zomwe sizingachitike; izi zidatsimikiziridwa ndi miyeso yamunda m'malo amizinda. Ma high-gain arrays amatha kuchepetsedwa ku ntchito za WPT.
Pofuna kusamutsa ubwino wa ma antenna okwera mtengo kupita ku ma RFEH okhazikika, njira zopakira kapena kukonza zimagwiritsidwa ntchito kuthetsa vuto la kuwongolera. Chingwe cha antenna chokhala ndi ma patch awiri chimapangidwa kuti chipeze mphamvu kuchokera ku ma RFEH ozungulira a Wi-Fi mbali ziwiri. Ma antenna a RFEH ozungulira amapangidwanso ngati mabokosi a 3D ndipo amasindikizidwa kapena kumamatira kumalo akunja kuti achepetse malo a dongosolo ndikulola kukolola mbali zambiri. Kapangidwe ka ma cubic rectenna kamasonyeza kuthekera kwakukulu kolandira mphamvu mu ma RFEH ozungulira.
Kusintha kwa kapangidwe ka antenna kuti kuwonjezere m'lifupi mwa beam, kuphatikizapo zinthu zothandizira parasitic patch, kunapangidwa kuti kuwonjezere WPT pa 2.4 GHz, 4 × 1 arrays. Antena ya 6 GHz mesh yokhala ndi madera angapo a beam inaperekedwanso, kuwonetsa ma beam angapo pa doko lililonse. Ma antenna okhala ndi ma port ambiri, multi-rectifier surface rectennas ndi energy harvesting okhala ndi ma radiation omnidirectional patterns aperekedwa kuti agwiritsidwe ntchito pa multi-directional ndi multi-polarized RFEH. Ma multi-rectifier okhala ndi ma beamforming matrices ndi multi-port antenna arrays nawonso aperekedwa kuti agwire ntchito pa high-gain, multi-directional energy harvesting.
Mwachidule, ngakhale ma antenna okwera mtengo amakondedwa kuti akonze mphamvu zomwe zimatengedwa kuchokera ku ma RF ochepa, ma receiver okwera mtengo kwambiri sangakhale abwino kwambiri m'magwiritsidwe ntchito komwe njira yotumizira siidziwika (monga, RFEH yozungulira kapena WPT kudzera munjira zofalitsira zosadziwika). Mu ntchitoyi, njira zingapo zoyezera mphamvu zambiri zikuperekedwa kwa WPT ndi RFEH okwera mtengo kwambiri.
2. Kugawanika kwa Antena
Kugawa kwa ma antenna kumafotokoza kayendetsedwe ka vekitala yamagetsi poyerekeza ndi njira yofalitsira ma antenna. Kusagwirizana kwa ma polarization kungayambitse kuchepa kwa kutumiza/kulandira pakati pa ma antenna ngakhale pamene malangizo akuluakulu a lobe agwirizana. Mwachitsanzo, ngati antenna yoyima ya LP ikugwiritsidwa ntchito pogawa ndipo antenna yopingasa ya LP ikugwiritsidwa ntchito pogawa, palibe mphamvu yomwe idzalandiridwa. Mu gawoli, njira zomwe zanenedwa zowonjezerera magwiridwe antchito a ma waya komanso kupewa kutayika kwa ma polarization zikuwunikidwanso. Chidule cha kapangidwe ka rectenna kokhudzana ndi kugawa kwaperekedwa mu Chithunzi 6 ndipo chitsanzo cha SoA chaperekedwa mu Table 4.
Chithunzi 6
Mu kulumikizana kwa mafoni, kulumikizana kwa mzere pakati pa malo oyambira ndi mafoni sikungatheke, kotero ma antenna a malo oyambira amapangidwa kuti akhale ndi ma polarized awiri kapena ma multi-polarized kuti apewe kutayika kwa ma polarization. Komabe, kusiyana kwa mafunde a LP chifukwa cha zotsatira za multipath kumakhalabe vuto losathetsedwa. Kutengera ndi lingaliro la malo oyambira oyambira oyambira ambiri, ma antenna a RFEH a m'manja amapangidwa ngati ma antenna a LP.
Ma CP rectenna amagwiritsidwa ntchito kwambiri mu WPT chifukwa salimbana ndi kusagwirizana. Ma CP antenna amatha kulandira kuwala kwa CP ndi njira yozungulira yomweyo (CP ya kumanzere kapena ya kumanja) kuwonjezera pa mafunde onse a LP popanda kutaya mphamvu. Mulimonsemo, CP antenna imatumiza ndipo LP antenna imalandira ndi kutayika kwa 3 dB (kutayika kwa mphamvu kwa 50%). Ma CP rectenna akuti ndi oyenera ma 900 MHz ndi 2.4 GHz ndi 5.8 GHz mafakitale, asayansi, ndi azachipatala komanso mafunde a millimeter. Mu RFEH ya mafunde ogawidwa mwachisawawa, kusiyanasiyana kwa polarization kumayimira njira yothetsera kutayika kwa polarization kosagwirizana.
Kugawa kwathunthu kwa ma polarization, komwe kumadziwikanso kuti multi-polarization, kwaperekedwa kuti kuthetseretu kutayika kwa ma polarization mismatch, zomwe zimathandiza kusonkhanitsa mafunde onse a CP ndi LP, pomwe zinthu ziwiri za LP zomwe zili ndi ma orthogonal awiri zimalandira bwino mafunde onse a LP ndi CP. Kuti timvetse izi, ma voltages olunjika ndi opingasa (VV ndi VH) amakhalabe osasintha mosasamala kanthu za ngodya ya polarization:
Mphamvu yamagetsi ya CP electromagnetic wave "E", komwe mphamvu imasonkhanitsidwa kawiri (kamodzi pa unit), motero imalandira gawo la CP mokwanira ndikugonjetsa kutayika kwa 3 dB polarization mismatch:
Pomaliza, kudzera mu kuphatikiza kwa DC, mafunde ochitika a polarization yosasinthika amatha kulandiridwa. Chithunzi 7 chikuwonetsa mawonekedwe a rectenna yodziwika bwino yolumikizidwa.
Chithunzi 7
Mwachidule, mu ntchito za WPT zokhala ndi magetsi apadera, CP imakondedwa chifukwa imawongolera magwiridwe antchito a WPT mosasamala kanthu za ngodya ya polarization ya antenna. Kumbali ina, mu kugula magwero ambiri, makamaka kuchokera ku magwero ozungulira, ma antenna odzaza ndi polar amatha kupeza bwino kulandira ndi kunyamula bwino kwambiri; mapangidwe a madoko ambiri/ma multi-rectifier amafunika kuti aphatikize mphamvu yodzaza ndi polarized pa RF kapena DC.
Chidule
Pepalali likuwunikanso kupita patsogolo kwaposachedwa pakupanga ma antenna a RFEH ndi WPT, ndipo likupereka gulu lokhazikika la kapangidwe ka ma antenna a RFEH ndi WPT lomwe silinaperekedwe m'mabuku am'mbuyomu. Zofunikira zitatu zazikulu za ma antenna kuti tikwaniritse bwino kwambiri RF-to-DC zadziwika kuti:
1. Bandwidth ya impedance yokonzanso ma antenna ya magulu a RFEH ndi WPT ofunikira;
2. Kugwirizana kwakukulu kwa lobe pakati pa chotumizira ndi cholandirira mu WPT kuchokera ku chakudya choperekedwa;
3. Kufananiza kwa polarization pakati pa rectenna ndi mafunde ochitika mosasamala kanthu za ngodya ndi malo.
Kutengera ndi impedance, ma rectenna amagawidwa m'magulu a 50Ω ndi rectifier conjugate rectennas, makamaka pa impedance matching pakati pa magulu osiyanasiyana ndi katundu komanso kugwira ntchito bwino kwa njira iliyonse yofananira.
Makhalidwe a kuwala kwa ma rectenna a SoA awunikidwanso kuchokera ku lingaliro la kuwongolera ndi polarization. Njira zowongolera kukwera kwa beamforming ndi kulongedza kuti zithetse m'lifupi mwake mopapatiza zafotokozedwa. Pomaliza, ma rectenna a CP a WPT awunikidwanso, pamodzi ndi njira zosiyanasiyana zopezera kulandira polarization kwa WPT ndi RFEH.
Kuti mudziwe zambiri zokhudza ma antenna, chonde pitani ku:
Nthawi yotumizira: Ogasiti-16-2024
