I would like to ask if a smart card reader can detect the smart card frequency in a long distance. the smart card reader on the market can only receive with a few centimeters. how can I change its circuits or parts to have a wider coverage? Please help
It sounds like you're not asking about magnetic card readers but RFID transponders? Certainly it can be more than a few centimeters, and there's lots of stuff on the market attempting to read transponders from a distance. There are two issues. The first is the quality of the reader (they can be changed out, but stronger ones cost more) and the transponder itself. For instance, I have EZ-Pass on my car - it lets me drive through a toll booth and it automatically picks up the info and charges me, and obviously I'm not driving my car just centimeters from the reader. The transponder I have to mount is just under an inch in thickness and about 16 square inches large. So it's not a trivial thing, and you wouldn't mount it on a CD in a record store. But yes, depending on the application, it can be changed. Are the changes too much for your intended use? I don't know, but it is possible, although it comes with some overhead. It can be done, though.
