Proposta de codificação multifrequencial e multitemporal para etiqueta RFID sem chip em substrato flexível.

Abstract

This dissertation addresses the design, analysis, and experimental validation of a coding structure for a chipless RFID tag developed on a flexible substrate with time domain and frequency domain coding. The combination of edge- and broadside-coupling in a multi-layer coupled line system is proposed. The validation of this approach is permormed by the analysis of coding structures with one section. Some charactheristics of transmission lines, such as coupling, line impedance and delay were analyzed for the frequency range of 2 GHz − 5 GHz. The coding structure is implemented on a Rodgers Ultralam 3850 flexible substrate with a permittivity of ǫr = 2, 9 and thickness 0, 1 mm. The one-section strucutre has a total area 133 mm2 and 247 mm2 for the two-section structure. Afterwards, with the thorough analysis of one section structure, two sections structure is analyzed. Therefore, for the use of more sections, cascaded structures can be employed. The structure analysis shows that the electromagnetic modeling agrees with the experiments performed, in frequency band the structure has negative group delay. Based on the measured and simulated results, was shown that this structure can be increased with more sections, increasing the coding capacity and shows good candidate toward to higher frequencies. Through the analysis of simulation for millimeter wave, seems possible scale the coding structure for higher frequencies. Then, the results shows that the coding structure analyzed has a great potential for the bit number expansion. In this way, any other application, which a larger number of bits is required, allying a simply manufacture technique, can be implemented.