Radio Frequency Identification

Radio-frequency identification (RFID) is one of the modern names that is becoming increasingly popular, as a result of many years of researches and investigations. Powerful hardware and software tools have contributed, and still do, to place the radio-frequency identification as a popular and widely used technology, from large corporations to individuals, and custom applications. Although RFID offers many advantages over other technologies, it is essential to be aware of its limitations. Therefore, it will be possible to overcome the limitations and to increase its applications. As an example, cost, safety, security, transmissions formats, and international standards are important merit figures of continuous improvement. In this book, we present important proposals that will certainly contribute to the evolution of RFID. Theoretical and practical aspects are presented and discussed by the authors, and thus we invite everyone for a pleasant reading

A Low Power CMOS Voltage Regulator for a Wireless Blood Pressure Biosensor

This paper describes a CMOS implementation of a linear voltage regulator (LVR) used to power up implanted physiological signal systems, as it is the case of a wireless blood pressure biosensor. The topology is based on a classical structure of a linear low-dropout regulator. The circuit is powered up from an RF link, thus characterizing a passive radio frequency identification (RFID) tag. The LVR was designed to meet important features such as low power consumption and small silicon area, without the need for any external discrete components. The low power operation represents an essential condition to avoid a high-energy RF link, thus minimizing the transmitted power and therefore minimizing the thermal effects on the patient's tissues. The project was implemented in a 0.35-mu m CMOS process, and the prototypes were tested to validate the overall performance. The LVR output is regulated at 1 V and supplies a maximum load current of 0.5 mA at 37 degrees C. The load regulation is 13 mV/mA, and the line regulation is 39 mV/V. The LVR total power consumption is 1.2 mW.CAPESCAPESMOSISMOSISCNPqCNPqFAPEMIGFAPEMI