I am absolutely ignorant about this technology so that question probably doesn't make sense. I need to know what type of passive reader and active system I need if I want the active to read the passive from up to 40 feet away. Is the passive system a chip, or would it be the size of the EZPass toll receivers?
Dear Ian McClelland, Hope you are doing great, for that distance the only Family that we have is the UCODE please check the image,
the only thing that I am not sure if you need a reader or a passive chip, let me quick explain, the passive chip will be the one that is waiting to be energized by the active in this case the reader, I mention this because NXP does not sell UHF (Ultra high frequency) readers for this we only have tags, if you are looking for a tag please check our UCODE family.