Research On RF Parametric Test System Of Flexible Thin Card

The technology of flexible thin card, which is working at the highfrequency of13.56MHz and has been widely used in the tickets field, such asthe Expo, Olympics and other major event, and the IC card field, such as thebus cards, social security card and ID card and so on, belongs to RFIDtechnology. But the international standards at this frequency are varied.Currently the standards of ISO/IEC14443A/B, ISO/IEC15693,ISO/IEC18000-3and Tag-it have been observed by the leading semiconductorcompany, such as Texas Instruments, NXP, Philips and so on, though theprocess of encoding and decoding, the methods of modulation anddemodulation, the requirements of magnetic field strength, the air interfaceand transmission protocols and the anti-collision algorithm are different,which lead the compatibility issues among the cards produced by differentmanufacturers. In addition, the technology of flexible thin card has beencombined to the computer technology, networking and communicationstechnology. Because the flexible card is efficient, fast, reliable, non-contact,and can be working in harsh environments, it has been widely used in manyother fields. So its security, stability, production costs and energyconsumption and other aspects should be considered to be focused on.Based on the electromagnetic theory which is closely related to thetechnology of flexible thin card, this paper has studied the principle ofinteraction between the card and test system and the basic communicationprocess. And laterally compared the standards of ISO/IEC14443A/B,ISO/IEC15693, ISO/IEC18000-3and Tag–it, we get the similarities anddifferences at the field of coding and decoding, modulation and demodulation,anti-collision algorithms and the transport protocol which are defined in thestandards. Finally, comparing the products at the technology of the controlchip and the RF front-end chip of the several major semiconductormanufacturers, we has selected the ultra-low-power MCU, MSP430of TexasInstruments, as the main chip, and the TRF7960chip, which is compatiblewith ISO/IEC14443A/B, ISO/IEC15693, ISO/IEC18000-3and Tag-it, as RF front-end chip. In addition, to get the most suitable working distance and themost intuitive interface of the actual operation, this paper designed theantenna including matching circuit and the interactive interface.The final testing results show that the system is compatible with allstandards of ISO/IEC14443A/B, ISO/IEC15693, ISO/IEC18000-3and Tag-it.The friendly interface can easily help us to visually know the various types ofcard. What’s more, the reading range of the test system is almost close to thevalue of theoretical design. In addition, with good prospects for development,the system can be very conveniently and applied to the relevant business areathrough a simple change of the software.