RFID Inductive vs. Backscatter Coupling Explained

How are passive RFID tags actually powered by an RFID reader?

Inductive and Backscatter coupling, that's how.

Check out my latest video explaining the difference between near-field and far-field RFID systems because they vary quite significantly in their approach.

#RFID #Coupling #IDMadeBetter #RFIDMadeBetter

[alan-mak]

Thanks for the sharing. Can you explain a little more on the backscattering? As far as I understand, there are two states in UHF RFID chip, absorbing state and reflecting state. I suppose the chip will stay in absorbing state until the transponder sensor (or receive) enough power to wake up the chip, then the transistor will be "on" and the chip will be in reflecting state. So backscattering happens when the chip is in reflecting state, my question is that does the transistor needs to be "on" and "off" (i.e switching between the two states), to modulate the return signal? or the transistor just keep "on" (i.e. keep staying in the reflecting state) and so the chip can transmit signal back to the reader? Also, how the Radar Cross Section (RCS) affect the return signal or return read range? How the chip knows when to be back to the absorbing state?

Moreover, as there is chip sensitivity, reader sensitivity, reader EIRP, etc. It is better if you can show us an example with some values, say EIRP = 30 dBm, reader antenna gain = 6 dBi, reader sensitivity = -75 dBm, UHF tag antenna = 2.15 dBi, chip sensitivity = -20 dBm ... and together with the backscattering and RCS.

Thanks

[humanbeing]

Thank you for your help and time taken to explain all of the details. I personally would have preferred a little bit more details instead of simplified general context. But you know better whom you are targeting.

[karthike]

tell me wheather the backscattered power can be used for any sensors

[frenofahad]

Any insights about RFID in aircraft parts?