Investigations to Achieve Very High Data Rates for Proximity Coupling Devices at 13.56 MHz and NFC Applications

This paper deals with the increase of data rates for proximity coupling devices and NFC systems. The paper gives an introduction to the basic functionalities of RFID systems at 13.56 MHz and sums the required regulation and standard. We compare different modulation and bit coding schemes in order to achieve bit rates of 6.78 Mbit/s. The signals are compared in terms of their spectral bandwidth, which is one of the main parameters for the communication in bandwidth limited channels. Measurements presented at the end of the paper show a comparison of different concepts. We show that higher order PSK modulation performs 23% better in terms of required field strength than ASK and 3 times better in terms of voltage stability at the card.