Basic Principple Of RFID System

Lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm RFID yog tias tus nyeem ntawv / sau ntawv xa cov teeb liab RF tshwj xeeb los ntawm lub kav hlau txais xov xa xov. Thaum lub cim hluav taws xob nkag mus rau thaj chaw ua haujlwm tau zoo, qhov cuam tshuam tam sim no raug tsim tawm, yog li tau txais lub zog kom tau txais, tso cai rau lub cim hluav taws xob xa nws cov ntaub ntawv encoded los ntawm lub kav hlau txais xov built-in; Tus kav hlau txais xov tau txais ntawm tus nyeem ntawv / tus kws sau ntawv tau txais cov teeb liab modulated xa los ntawm lub cim thiab xa mus rau tus nyeem ntawv / sau ntawv teeb tsa ua haujlwm los ntawm kev hloov pauv ntawm tus kav hlau txais xov. Tom qab tau demodulated thiab decoded, cov ntaub ntawv zoo raug xa mus rau tus tswv tsev keeb kwm yav dhau los rau kev ua haujlwm cuam tshuam; Lub kaw lus tswj hwm lees paub tus kheej ntawm daim ntawv cim raws li kev ua haujlwm ntawm cov laj thawj, ua cov txheej txheem sib txuas thiab kev tswj hwm rau cov chaw sib txawv, thiab thaum kawg xa cov teeb liab los tswj tus nyeem ntawv kom ua tiav cov kev nyeem thiab sau ntawv sib txawv.
Los ntawm qhov kev xav ntawm kev sib txuas lus thiab kev paub lub zog ntawm cov cim hluav taws xob thiab cov nyeem ntawv, RFID systems feem ntau tuaj yeem muab faib ua inductive coupling (magnetic coupling) systems thiab electromagnetic backscatter coupling (electromagnetic coupling) systems. Inductively coupled systems yog ua ke los ntawm high-frequency alternating magnetic teb nyob rau hauv qhov chaw, raws li txoj cai ntawm electromagnetic induction; Electromagnetic backscatter coupling, los yog radar qauv qauv, hais txog qhov kev xav ntawm electromagnetic nthwv dej tawm thaum lawv ntsib lub hom phiaj, thaum nqa rov qab cov ntaub ntawv, raws li txoj cai spatial propagation ntawm electromagnetic tsis.
Inductive coupling feem ntau haum rau luv luv RFID systems ua haujlwm ntawm nruab nrab thiab qis zaus; Electromagnetic backscatter coupling yog feem ntau haum rau RFID nyob deb ntawm cov tshuab uas muaj ntau zaus thiab microwave ua haujlwm zaus.