>On Fri, 26 Jul 2002, Tony Baia wrote:
>>What implications if any exist by having various components (PIC
>>included) within a 13.56MHz RF coil that has been etched on a
>>PCBoard.
Peter sez:
>The sinister black art of RF will ensure that the field is maximum inside
>the coil, i.e. in your circuit, and that you are thus forbidden:
>- Closed circuit patterns
>- Patterns that may cause RF from the coil or RFID exciter to cause
>misread digital or analog signals by rectification or glitching
>- anything else that I may have forgotten
>
>Otoh, all RFID 'credit card' type devices happily work inside a 13.56MHz
>fields. So there is a way to do it.

I don't think the chip is bothered much, what you have to look out
for is the antennas (meaning the signal wires coming into the chip)!
14 Mhz has a 20-meter wavelength, so wire length isn't as much an
issue as capacitively coupled energy.  (aka, the "E" field).  But
that's a guess.

Barry

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