[ale] Radio-frequency identification (RFID) chips

[Michael Mealling]

On Wed, 2004-01-07 at 13:54, Mike Murphy wrote:
> question: what's the typical range at which one can get data out of an 
> RFID chip?

Given the following assumptions:

1) nothing between the chip and the reader

2) a good, expensive antenna

3) the chip is not moving

4) and the chip is a high quality design (good power, good antenna)
   (this usually means the entire tag is about 6-8 inches square)

Then you can usually get a greater than 90% read rate around 25 feet.
Think of the size of a typical dock door and you get the idea of the
intended ranges.

The readers that I've been playing with cost about $5,000 and can read
even poor quality tags within about 1-2 feet reliably.

The reader I describe above with teh 20 foot range costs around $50,000
I think....

-MM