Behnam Jamali

Small UHF RFID Label Antenna Design and Limitations

Radio Frequency Identification (RFID) is emerging as an unrivalled contender for automatic object identification technology, its adoption being driven primarily by the potential cost savings in the application of the technology to supply chain management [1]. In general RFID system components include RFID labels, Interrogators (transceivers) and backend control and data collection systems [2]. The mass utilization of RFID technology is hindered by the cost of RFID labels. The cost of producing a label can be separated into IC design, IC manufacture, antenna manufacture, antenna and IC assembly, and packaging. Significant barriers to reducing the cost are the lack of a streamlined process for attaching a RFID label antennas to RFID ICs (about 0.25 mm in size) and the cost of manufacturing antennas, which currently cost around 3 4 US cents per label. Hence this paper focuses on low cost passive RFID labels with the aim of reducing passive labels costs.

Design and optimisation of Schottky diodes in CMOS technology with application to passive RFID systems

In this paper, we present and analyze the most fundamental constraint of RFID systems, power rectification. This issue plays an important role in development of long-range RFID systems. Rectifiers are the key components in power rectifications and efficiency of an RFID system. Therefore this paper is concentrated in investigating this major issue. To tackle this problem a novel Schottky Barrier Diode (SBD) has been proposed. The proposed SBD provides good power conversion rate and switching properties.

Analysis of UHF RFID CMOS rectifier structures and input impedance characteristics

Passive radio frequency identification (RFID) systems deployment efforts are revolutionizing supply chain logistics by providing unprecedented supply chain visibility. The widely used bandwidth of operation in modern systems is the UHF ISM (industrial, scientific, and medical) band. The performance of UHF RFID systems are largely reliant on low power CMOS circuits, efficient power rectification and the ability of RFID label antennas to match to the input impedance of the RFID label IC. This paper examines a new rectifying structure and considers it for its merits in RFID applications while analysing contribution of the rectifying structure to the input impedance of RFID chips as this is an important consideration in impedance matching to an external antenna.

Turn-on circuits based on standard CMOS technology for active RFID labels

The evolution of RFID Systems has lead to the development of a class hierarchy in which the battery powered labels are a set of higher class labels referred to as active labels. The battery powering active transponders must last for an acceptable time, so the electronics of the label must have very low current consumption in order to prolong the life of the battery. However due to circuit complexity or the desired operating range the electronics may drain the battery more rapidly than desired but use of a turn-on circuit allows the battery to be connected only when communication is needed, thus lengthening the life of the battery. Two solutions available for the development of a turn on circuit use resonance in a label rectification circuit to provide a high sensitivity result. This paper presents the results of experiments conducted to evaluate resonance in a label rectification circuit and the designs of fully integrable turn-on circuits. We have also presented test results showing a successful practical implementation of one of the turn on circuit designs.

Comparative study of microstrip patch antenna feed network

This paper presents a comparative study of patch antenna feed structures. That includes microstrip line feed, inset feed, coaxial feed, aperture coupled feed and proximity coupled feed. Matching between the patch antenna and the feed network heavily depends on the feed technique used. In this work we review various feeding techniques to provide an understanding of the important design parameters and their effects on the bandwidth, gain and the other important antenna characteristics. Various simulation tools, commercial and internally developed are used during this work.

An integrable low-cost hardware random number generator

A hardware random number generator is different from a pseudo-random number generator; a pseudo-random number generator approximates the assumed behavior of a real hardware random number generator. Simple pseudo random number generators suffices for most applications, however for demanding situations such as the generation of cryptographic keys, requires an efficient and a cost effective source of random numbers. Arbiter-based Physical Unclonable Functions (PUFs) proposed for physical authentication of ICs exploits statistical delay variation of wires and transistors across integrated circuits, as a result of process variations, to build a secret key unique to each IC. Experimental results and theoretical studies show that a sufficient amount of variation exits across IC’s. This variation enables each IC to be identified securely. It is possible to exploit the unreliability of these PUF responses to build a physical random number generator. There exists measurement noise, which comes from the instability of an arbiter when it is in a racing condition. There exist challenges whose responses are unpredictable. Without environmental variations, the responses of these challenges are random in repeated measurements. Compared to other physical random number generators, the PUF-based random number generators can be a compact and a low-power solution since the generator need only be turned on when required. A 64-stage PUF circuit costs less than 1000 gates and the circuit can be implemented using a standard IC manufacturing processes. In this paper we have presented a fast and an efficient random number generator, and analysed the quality of random numbers produced using an array of tests used by the National Institute of Standards and Technology to evaluate the randomness of random number generators designed for cryptographic applications.

Exploiting metastability and thermal noise to build a re-configurable hardware random number generator

While pseudo random number generators based on computational complexity are widely used for most of cryptographic applications and probabilistic simulations, the generation of true random numbers based on physical randomness is required to guarantee the advanced security of cryptographic systems. In this paper we present a method to exploit manufacturing variations, metastablity, and thermal noise in integrated circuits to generate random numbers. This metastability based physical random number generator provides a compact and low-power solution which can be fabricated using standard IC manufacturing processes. Test-chips were fabricated in TSMC 0.18um process and experimental results show that the generated random bits pass standard randomness tests successfully. The operation of the proposed scheme is robust against environmental changes since it can be re-calibrated to new environmental conditions such as temperature and power supply voltage.

Design and optimisation of power rectifiers for passive RFID systems in monolithic CMOS circuit

In this paper, we present and analyze the most fundamental constraint of RFID systems, power rectification. This issue plays an important role in development of long-range RFID systems. Rectifiers are the key components in power rectifications and efficiency of an RFID system. Therefore this paper is concentrated in investigating this major issue. To tackle this problem a novel Schottky Barrier Diode (SBD) has been proposed. The proposed SBD provides good power conversion rate and switching properties.

RFID Tag Vulnerabilities in RFID Systems

More than half a century after its inception, radiofrequency identification (RFID) technologies are finally living up to their long promised capabilities. They are being rewarded with pervasive deployments in closed loop applications and the initial deployments in the even more pervasive open loop supply chain management applications. By providing accurate, real-time, human out-of-the loop asset and product monitoring throughout the world’s supply chains, RFID technologies are beginning to improve the efficiency and security of these chains. The use of RFID technologies in these open loop supply chains is still in its infancy with all of the learning and growing pains that the introduction of a new technology entails. Security is of paramount importance in the deployment of RFID systems, particularly when they are being deployed, in part, to enhance the security of the supply chains. It is therefore appropriate that we examine now the potential security vulnerabilities inherent in the RFID systems currently being deployed in the supply chains of the world. Instead of covering the expansive RFID security landscape in this paper, we focus on the security vulnerabilities in the use of the data retrieved from an RFID tag. We conclude that the data stored on an RFID tag provides no more a security vulnerability to a system than any other manner of importing data into that system. Furthermore, the limited and highly structured nature of the data stored on the license plate RFID tags being used for supply chain management eliminates the potential for any security vulnerability due to the use of the tag data in a competent system.

CRISP: A flexible integrated development platform for RFID systems

Radio Frequency Identification (RFID) is a technology to store and retrieve information remotely using electromagnetic waves. RFID is poised to drastically change the way industries collect and manage information. Research in this area has been growing in the past few years given the wide range of applications that can benefit from such a technology. In this paper we introduce the Cognitive RFID Integrated System Platform (CRISP), a framework for development and implementation of RFID communication protocols. The framework enables advanced research in the area of RFID wireless communication protocols and algorithms. As such, CRISP provides a flexible, scalable, configurable and high performance RFID research tool. In the following sections the CRISP hardware implementation and software architecture are discussed in detail. Radio configurations and applications are presented. Future research made possible by this flexible platform is also discussed.