Ukubekwa Kwe-Antenna & Ukuthuthukisa

Ukubekwa kwe-Antenna yisici esingu-#1 ekusebenzeni kwesistimu ye-RFID. kubaluleke kakhulu kunokuzwela kwe-tag noma amandla omfundi. Umfundi ongu-$5,000 one-antenna ebekwe kabi ngeke asebenze kahle kunomfundi ongu-$500 one-antenna ebekwe kahle. Umgomo uwukudala indawo yokufunda echazwe kahle (isikhala se-3D lapho ama-tag afundwa ngokwethembeka) ngenkathi kuncishiswa ukufunda okulahlekile ngaphandle kwendawo okuyiwa kuyo.

Isibonelo sangempela: ukuhambisa i-antenna yomnyango we-dock ukusuka ekuphakameni okungu-2.5m ukuya ekuphakameni okungu-2.0m nokuyitshekisa ngo-15° phansi kuthuthukise amazinga okufunda ukusuka ku-87% kuya ku-99.2% ekuthunyelweni okukhulu kwezinto.

I-polarization ye-antenna inquma ukuthi amaza kagesi azobhekiswa ngakuphi. Lesi sinqumo esibaluleke kakhulu ekwakhiweni kwesistimu ngoba silawula ngqo ukuthi ama-tag asezindaweni ezihlukahlukene azofundeka yini.

Indawo yokufunda iyivolumu ye-3D lapho ama-tag angafundwa ngokwethembeka. Imise okwekhoni noma i-lobe evela ebusweni be-antenna, enezilinganiso ezinqunywa yi-antenna gain, amandla omfundi we-TX, kanye nokuzwela kwe-tag. I-antenna engu-9 dBic enamandla angu-30 dBm eno-NXP UCODE 9 tag (-22.1 dBm sensitivity) idala indawo yokufunda ecishe ibe ngu-8–10 amamitha ukujula futhi ibe ngu-3–4 amamitha ububanzi ekugcineni.

Near-field vs Far-field: Ama-antenna e-UHF RFID asebenza ezindaweni ezimbili. I-near-field (ngaphakathi ~35cm at 920 MHz) isebenzisa ukuxhumeka kwamagnetic okufundwayo okufushane kakhulu, okulawulwayo. ilungele iziteshi ze-POS lapho ufuna ukufunda kuphela izinto ezikunethe.

Iziqondiso zamandla: 33 dBm for maximum range (~10m, dock doors). 30 dBm for standard range (~6–8m, general use). 25 dBm for medium range (~3–5m, conveyor belts). 20 dBm for short range (~1–2m, point-of-sale). 15 dBm for near-field (~0.5m, shelf readers). Njalo qala ngamandla aphansi bese ukhuphula uze uthole izinga lakho lokufunda eliqondiwe. amandla amaningi abangela ukufunda okulahlekile.

33 dBm → ~10m   dock doors, max range
30 dBm → ~6-8m  general warehouse
25 dBm → ~3-5m  conveyor belts
20 dBm → ~1-2m  point-of-sale
15 dBm → ~0.5m  shelf / near-field

I-VSWR (Voltage Standing Wave Ratio) ilinganisa ukuthi amandla adluliselwa kahle kangakanani ukusuka kumfundi kuya ku-antenna. Ukufana okuphelele kungu-1:1 (wonke amandla akhishwayo). Noma yini engaphezu kuka-2:1 isho ukuthi amandla amakhulu abuyiselwa emuva kumfundi, okunciphisa ukusebenza futhi okungenzeka ukuthi kulimaze i-PA amplifier ngokuhamba kwesikhathi. Iningi lama-antenna ezentengiso ze-RFID lithola i-1.2–1.5:1 VSWR kulo lonke ibhendi elisebenzayo.

Izinkinga ezivamile ze-VSWR: Izintambo ze-RF ezilimele noma ezigobile (zishintshe uma i-VSWR idlula ku-2:1). Uhlobo lwesixhumi olungalungile (sebenzisa i-RP-TNC noma i-SMA njengoba kucacisiwe). I-Antenna efakwe ngqo endaweni yensimbi ngaphandle kwe-spacer (sebenzisa i-15mm+ standoffs). Ukungena kwamanzi kuma-connector angaphandle (sebenzisa i-RP-TNC engangeni manzi enezicathulo). Ubude bekhebula obudlula ku-10m ngaphandle kwekhebula elilahlekelwa kancane (sebenzisa i-LMR-400 noma okulinganayo ngemijaho engaphezu kuka-5m).

Njalo qinisekisa i-VSWR kulo lonke ibhendi lakho elisebenzayo (920–925 MHz for Vietnam). I-antenna ingase ikhombise i-1.2:1 VSWR enhle ku-920 MHz kodwa yehle ibe ngu-2.5:1 ku-925 MHz. okusho ukusebenza okubi ezingxenyeni zakho ze-FHSS.

Ukuthunyelwa okuningi kokukhiqiza kusebenzisa ama-antenna amaningi ngomfundi ngamunye. Abafundi be-Nextwaves basekela kuze kufike emachwebeni e-antenna angu-32. Okubhekwayo okubalulekile: Ukuhlukaniswa. ngokuvamile amamitha angu-1–2 ukusuka komunye nomunye eminyango yezindawo zokubeka, ngokuqondana kwemisebe engu-15–20% ukuze kutholakale ukumbozwa okuphelele. I-engeli yokukhweza. 15–45° ukuthambekela ngaphakathi kwezicelo ze-portal ukuze kugxilwe endaweni yokufunda emnyango. Ukulandelana kwe-antenna. umfundi ushintsha phakathi kwama-antenna ngokuzenzakalelayo ukuvimbela ukudluliswa ngesikhathi esisodwa kusuka ezindaweni ezigqagqanayo.

Isibonelo sokucushwa kwe-Portal (umnyango wokubeka): Faka ama-antenna angu-4. 2 ohlangothini ngalunye lomnyango ngamamitha angu-1.5m no-2.5m ukuphakama, ethambekele ngaphakathi ngo-30°. Sebenzisa i-polarization eqondile eqondiswe ebusweni be-pallet. Setha umfundi ku-Session S2 nge-Q=6 yama-forklift ahamba ngokushesha. Lokhu kunikeza amazinga okufunda angu-99%+ emithwalweni ejwayelekile ye-pallet yezigaba ezinamathelwe ezingu-48–100.

Isibonelo somhubhe we-conveyor: Faka ama-antenna angu-4 aqondiswe ngesimo esiyisikwele ngaphakathi kwebhande. phezulu, phansi, kwesobunxele, kwesokudla. Setha i-Session S1 yokufunda okukodwa. Amandla angu-25 dBm ukuze kuvinjelwe indawo yokufunda emhubheni. Lokhu kuvimbela ukufunda amathegi kuma-conveyors aseduze.

CONFIGURE_ANTENNA_ENABLE payload (4 bytes):

Ports 1-4:    0x0F 0x00 0x00 0x00  (0b00001111)
Ports 1,3:    0x05 0x00 0x00 0x00  (0b00000101)
Port 1 only:  0x01 0x00 0x00 0x00  (0b00000001)

Bit 0=ANT1  Bit 1=ANT2  ...  Bit 31=ANT32

Izindawo zensimbi ziyimthombo wokuphazamiseka ongu-#1 ezinqolobaneni. Zibonisa amasignali e-RF, zakhe izindawo ezingasebenzi nokuphazamiseka kwe-multipath. Isixazululo: faka ama-antenna ezindaweni ezingeyona insimbi noma usebenzise ama-standoff angu-50mm+ kusuka ezakhiweni zensimbi. Qondisa ama-antenna ukuze i-lobe enkulu ingashayi izindonga zensimbi noma ukubeka ngqo.

Amanzi kanye noketshezi kumunca amaza omsakazo e-UHF kakhulu. Ikesi lamabhodlela amanzi phakathi kwe-antenna kanye ne-pallet enamathelwe lingavimba ukufunda ngokuphelele. Isixazululo: beka ama-antenna ukuze indlela ye-RF igweme iziqukathi zoketshezi, noma ukwandise amandla ngo-3–6 dB ukukhokhela ukulahleka kokumuncwa.

Abanye abafundi abasebenza eduze bangadala ukuphazamiseka. I-Dense Reader Mode (DRM) kanye ne-FHSS kuyasiza, kodwa izinyathelo ezengeziwe zihlanganisa: ukucushwa kwamaski esiteshi esingahambelani phakathi kwabafundi abaseduze, ukusebenzisa ama-antenna aqondisayo ukukhawulela ukuconsa, nokusebenzisa ukuhlela kwe-TDMA uma i-middleware yakho ikusekela.

Gcina ama-antenna ≥1m kude nezibani ze-fluorescent (umthombo womsindo we-RF) kanye no-≥2m kude nezindawo zokufinyelela ze-Wi-Fi. Ngenkathi i-Wi-Fi isebenza ku-2.4/5 GHz (ihlukile ku-UHF 920 MHz), imishini engavikeliwe kahle ingakhiqiza ama-harmonics e-broadband.