Transfer function of a 13.56MHz RFID channel

In this contribution we derive the transfer function of a typical RFID channel as defined in ISO 14443. RFID is common technology and has applications in various contexts such as keyless entry and logistics. In the following the principle of such a system is briefly outlined and an equivalent circuit is introduced. The transfer function itself is derived via a state space model approach which are a widely used concept, especially in control engineering. Finally the resulting transfer function is compared to a conventionally derived transfer function. The results show that the derived function is correct within the inherent errors of such concepts and approximations. In addition, the resulting matrix-shape state space model is a good basis for further investigations such as mitigating intersymbol interference on the channel.