tailieunhanh - Radio Frequency Identification Fundamentals and Applications, Design Methods and Solutions Part 14

Tham khảo tài liệu 'radio frequency identification fundamentals and applications, design methods and solutions part 14', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 316 Radio Frequency Identification Fundamentals and Applications Design Methods and Solutions register the 3-bit binary counter and the 8-bit line select. The 8-bit line select has an internal 3-bit binary counter and a 3-to-8 decoder. This block selects a row of 8 bits in the code. The 3-bit binary counter drives the 8 1 multiplexer selecting a column of 8 bits in the code matrix. The data bit at the crossing of the active row and column is transported via a 8 1 multiplexer to the output register which sends this bit on the rising edge of the clock to the modulation transistor. The 3 bits of the 3-bit binary counter are also used in the 8-bit line select block for selecting a new row after all 8 bits in a row are transmitted. I clock generator Ị- Fig. 5. Schematic overview of the digital logic part of the 64-bit transponder chip. The 64-bit transponder foil comprises only 414 OTFTs. Figure 2 shows a micrograph image of the transponder foil. At 14 V supply voltage the 64-bit transponder foil generates the correct code at a data rate of 752 b s which is depicted in Fig. 6. Besides the 64-bit transponder foil we also designed an 8-bit transponder foil. The main difference in the design is the complexity of the line select. Fig. 6. Measured code of the 64-bit transponder chip at a supply voltage of 14 V. 4. Organic rectifier Organic diode The purpose of the rectifier in an RFID tag is to create a DC-voltage from the AC-voltage detected and generated by an antenna at the targeted base carrier frequency of MHz. This frequency is selected because it is a standard in Si-based RFID tags and will therefore Organic RFID Tags 317 enable partial compatibility with installed reader systems at MHz. An important issue for organic RFID tags is the efficiency of the rectifier. A more efficient rectification will result in the required DC-voltage from lower AC-input voltage. This implies larger reading distances for the RFID tags Myny et al. 2008 Myny et al. 2009 . A