simon yong
Joined: 09 Mar 2008
Posts: 10
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 17 Mar 2008 16:55 low frequency RFID and bandwidth choosing |
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i need to do simulation base on the low frequency RFID.
simulation is base on matlab and how to characterize it.
so i will simulate the radiation pattern of antennas, and might be the smith chart.
what i want to ask is what else i can simulate to characterize the low frequency RFID?
beside that, how i specify the simulation in low frequency type?
i'm not sure the radiation pattern of antennas, is it can specify the simulation in low frequency?
may i know that in choosing a bandwidth for low frequency in standard RFID, 125kHz, how many % of bandwidth i should use?
please help me because i really need the information to do my final year project.
i was out of idea and panic now.
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streamlet
Joined: 24 Dec 2007
Posts: 62
Helped: 7
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26 Mar 2008 10:48 low frequency RFID and bandwidth choosing |
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We know that the power and signal transmission in LF RFID system is based on a transformer model. So you only need to simulate the coupling factor between reader antenna and tag antenna. Then combine the coupling factor with other circuit parameters on both reader side and tag side, like the input impedance of reader and tag antennna, and tag load. After this, you will be able to see the voltage and power the tag can get.
The radiation pattern of antennas in LF RFID systems is not very useful, because it will change from place to place with the distance away from the antenna as long as the power transmission happens within near field.
As for the bandwidth, you need to check it in the relative standard or protocol. Pay attention to the quality factor of antennas to satistify the bandwidth afterwards.
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