RFID modulation and Encoding

RFID modulation and Encoding

Modulation

Sound is converted to electricity by a telephone and then transmitted as an analog signal.

These waves has 3 fundamental characteristics:

1. Amplitude, meaning the height (intensity) of the wave
2. Frequency, which is the number of waves this pass in a single second and was measured in Hertz (cycles/second) (Wavelength, The length of the wave from crest to crest, was related to frequency.).
3. Phase is a third characteristic this describes the point in the wave's cycle at which a wave begins and are measured in deg Rees. (for example, changing a wave's cycle from crest to trough corresponds to a, degree phase shift).

Most RFID tags were using ASK (amplitude shift keying), FSK (Frequency shift keying) and PSK (Phase shift keying) for its Analog modulation.

Picture 3. RFID modulation.

For encoding, the most of them is using NRZ, Manchester,

Unipolar RZ, DBP (differential bi-phase),

Miller and differential Coding on PP Coding.

RFID modulation and Encoding