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Goal: I would like to be able to transfer some information to an Arduino Uno board via an NFC shield/antenna. The situation requires that the NFC tag may potentially hit anywhere within a circular area about a 12 inches in diameter.

Is it possible to increase the size of an NFC antenna? Possibly creating a loop antenna whereby the tag could be read from anywhere inside the loop.

I was thinking maybe if that isn't possible, it might be better to create an antenna array spanning the size of the area needed. Though I may have problems with overlap or double reads this way.

Has anyone attempted this before?

Note: I am not worried about increasing the z distance from the plane, just the x/y range. In fact, I still want the z distance to be very short as to not interfere with other antennas nearby.

aowie1
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1 Answers1

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In general the size and geometry of the antenna is directly related to the carrier frequency. The antenna is tuned to the output signal of the transmitter/receiver. If you change an optimized antenna, it is no longer optimized and its performance will drop. So you can't keep extending an antenna, trying to improve its range.

The important question to be asked is if the existing antenna is already optimally sized for the transmitter/receiver. With these small things transmitter/receiver and antenna are usually closely matched. Even if the antenna is smaller than expected by math, the transmitter/receiver connected to it may be compensated for that.

With a receiver or a low* power transmitter, there is no harm in testing another antenna, but you'll probably won't improve performance much.

*) Notice that a high power transmitter can blow its output stage when connected to an unmatched load/antenna, but that is unlikely with NFC.

jippie
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