The RFID- Handbook contains all information about RFID, Radio Frequency Identification, Transponder, RFID Tag, RFID Reader, 14443, 15693, 18000, GTAG, EPC, Antenna, ...

How to pick up RFID-signals?

 The following picture shows a command, transmitted by a reader, followed by the load modulation-signal of the transponder. The signal catched here is a REQA-command, according to ISO 14443 with the first bit of the answer, following within 86µs. Ther carrier frequency is 13.56 MHz.

To pick up such signals you need neither special probes nor expensive equipement. Just connect the ground-clip of your oscilloscope-probe with the probe-pin, as shown below. This makes your probe a 1-turn-sense-coil! The inductivity and enclosed area is enough to pick a enough energie from the field to display the signals at the scope, even at lower frequencies around 125 kHz.

Next, place the probe as close as possibele to the transpoder and the reader antenna, as shown below.

That’s enough to get quite clear signals from your system ...

Free sample reader: chapter 3 (Fundamental Operating Principles of RFID-Systems)