Automated analysis of ISO/IEC14443A interrogator command pulse shapes

Conformity compliance tests are important measures to mitigate interoperability issues in open-loop RFID applications like e-Banking and e-Passport applications where interrogators and transponders are normally supplied by various different manufacturers. Timing evaluation is a crucial part of the conformance compliance tests. Therefore, it is necessary to have an exact evaluation method in place in order to avoid ambiguities and to reduce the degree of freedom in the interpretation of measurement results. A novel automated analysis of ISO/IEC 14443A interrogator command pulse shapes resistant to signal distortion is proposed in this manuscript. The envelope detector required is based on the Hilbert transform in the frequency domain. A theoretical analysis has shown that at least one base-band filter is required to reject phase noise and harmonic distortion on the signal envelope. Furthermore, the properties, especially the windowing effect, of the FFT and iFFT have to be taken into account to get proper results.