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RFID: two sides of the door

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yura

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I'd like to use one RFID reader to read tags from the both sides of the steel door.
What's the best way to do this? Would the parallel antenna work?

Currently the reader is mounted on the internal side, and antenna is outside.

Thanks.
Happy new year!
 

flatulent

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It would probably be cheaper to have two readers than to successfully modify the reader to work with two antennas.

Is the wall material next to the door more transparent to RF? Try mounting the reader on the wall and using it from the other side of the wall.
 

yura

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The wall is thick (abt. 25cm), so the reader can't read from the other side.
 

biff44

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I would empirically try it out. Just because there is a steel door does not mean the wall is also solid steel, or that the door edge does not leak RF energy.
 

yura

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No, I meant that reader can't read from that distance even without the wall. The maximum read out distance I measured was approx 10cm.
 

artem

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Just make 2 antennas as one loop , where each is half of te original - look like serially connected coils. Impact will be i reduced senstivity equ decrease of distance. That is one solution .

Second is to use analog HF switch (relay and others) to select antenna to use and sequentially switch between antennas - means longer response to read transponder .
 

yura

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Second sounds reasonable. Especially that I have one free digital output pin on the reader.
Thanks!
 

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