What is the difference between nfc, rfid and a regular antenna?

[Jake9821]

Hey all, so im considering building a little rfid reader based system to unlock a door for fun. Well, I have it mostly built now. But I got thinking on what if I stuck a regular old antenna from a router and soldered it on where the rfid reader is. Would this increase the rfid range? Or can regular antennas not do that.

 

Basically what im asking is, can you replace nfc, rfid or other antennas with those found on the backs of wifi routers? Would this work? Thanks

[SansVarnic]

RFID and NFC are very different from wifi.

They are designed to be used in very short bursts and in most cases the RFID and NFC get their power from the respective reader.

RFID max range is like 1 inch.

NFC can transmit up to 30 ft but NFC chips are the same as RFID max range is about .5 inch.

 

*forgot to add that RFID and NFC wavelengths/strengths are by design to diffuse easily over short distances and not penetrate well.

[fordy_rounds]

An important difference is that RFID and NFC both require a coil antenna, while wifi usually is a straight antenna. This is important, because the coil antenna acts as an inductor, inducing current when exposed to a magnetic field. That's how NFC/RFID devices can be battery-less (e.g. a scannable badge, a toll-road sticker, etc.); they get their power wirelessly from the "reader." The reader also has to have a coil so that its current induces the right magnetic field. If you replaced that with a wifi antenna, it won't induce the magnetic field, and your tags won't get the field they need to power on.