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关键词： Ultra-High Frequency (UHF) RFID tag antenna   Impedance matching   Magnetic coupling   Dual resonance  

摘要： A novel low-profile metal mountable UHF RFID tag antenna is presented. The tag antenna design consists of two resonating patches with different resonant frequencies fed through a joint inductive loop. This design topology offers benefits such as bandwidth enhancement in the single band and the possibility of attaining a tunable dualband coverage in the UHF RFID band. The proposed antenna structure doesn't require any electrical connection (shorting pins/shorting plates/via holes) and therefore facilitates fabrication through a conventional RFID inlay manufacturing process. Fabrication and testing of a prototype of the proposed antenna design are carried out. The prototype antenna achieves free space and an on-metal reading range of better than 8 m and 11 m respectively in the US RFID band of 902-928 MHz.

关键词： Security   IoT   WSN   RFID  

摘要： The Internet of Things (IoT) has garnered significant attention from people with growing changes in human life over the last few years. IoT is a network of a group of smart devices that use sensors to collect information and conduct events in their environments. The information can then be shared on the Internet. IoT uses a range of technologies and finds various applications such as smart homes, environmental monitoring, and healthcare. In this paper, we conducted a comparative study to analyze the difference between two technologies-Wireless Sensor Networks (WSNs) and Radio Frequency Identification (RFID). It is pertinent to note that these technologies would not be effective without incorporating security aspects due to a potential number of threats and attacks on the network. This paper provides a comprehensive review of the recent approaches to securing RFID and WSNs. We have carefully chosen most of these studies to investigate only the recent technique from 2017 to 2020. The paper also highlights common attacks on RFID and WSNs and the secure authentication mechanisms on these technologies. It further provides a different way of detecting varying attacks in RFID and WSNs.

关键词： Bit error rate   Resonators   Scattering   Clutter   Radar cross-sections   Standards   RFID tags   Bit error rate (BER)   chipless RFID   communication systems   frequency-selective surfaces (FSSs)   radar cross section (RCS)  

摘要： The performance of different chipless RFID tag topologies is analyzed in terms of radar cross section (RCS) and bit error rate (BER). It is shown that the BER is mainly determined by the tag RCS once a standard reading scenario is considered and a fixed size of the tag is chosen. It is shown that the arrangement of the resonators in the chipless tag plays a crucial role in determining the cross-polar RCS of the tag. The RCS of the tag is computed theoretically by using array theory where each resonator is treated as a separate scatterer completely characterized by a specific reflection coefficient. Several resonators arrangements (periodic and nonperiodic) are compared, keeping the physical area of the tag fixed. Theoretical and experimental analyses demonstrate that the periodic configuration guarantees the maximum achievable RCS, thus providing a global lower BER of the chipless RFID communication system. We believe that the BER is the more meaningful and fair figure of merit (FoM) for comparing the performance of different tags than bit/cm(2) or bit/Hz since the increase in encoded information of the tag is useful only if it can be correctly decoded.

关键词： Axial Ratio (AR)   Coplanar Waveguide (CPW)   Circularly Polarized (CP)   Global Positioning System (GPS)   RFID reader   Ultrahigh Frequency (UHF)  

摘要： A novel compact printed broadband circularly polarized slot antenna is proposed in this paper. The antenna consists of an inverted L-shaped coplanar waveguide feed structure and a square ground plate loaded with three rectangular slots. The antenna achieves good impedance matching and circular polarization characteristics by adjusting the size of the L-shaped band and the rectangular slot. The simulation results show that the antenna has a 10-dB impedance bandwidth of 1360 MHz (690-2050 MHz) and a 3 dB axial ratio (AR) bandwidth of 490 MHz (770-1260 MHz). Additionally, the maximum gain reached 4.02 dBi. The antenna proposed in this paper can be applied to UHF RFID and GPS frequency bands.

关键词： indoor localization   radio frequency identification (RFID)   Kalman filter (KF)   semi-definite programming (SDP)  

摘要： State-of-the-art radio frequency identification (RFID)-based indoor autonomous vehicles localization methods are mostly based on received signal strength indicator (RSSI) measurements. However, the accuracy of these methods is not high enough for real-world scenarios. To overcome this problem, a novel dual-frequency phase difference of arrival (PDOA) ranging-based indoor autonomous vehicle localization and tracking scheme was developed. Firstly, the method gets the distance between the RFID reader and the tag by dual-frequency PDOA ranging. Then, a maximum likelihood estimation and semi-definite programming (SDP)-based localization algorithm is utilized to calculate the position of the autonomous vehicles, which can mitigate the multipath ranging error and obtain a more accurate positioning result. Finally, vehicle traveling information and the position achieved by RFID localization are fused with a Kalman filter (KF). The proposed method can work in a low-density tag deployment environment. Simulation experiment results showed that the proposed vehicle localization and tracking method achieves centimeter-level mean tracking accuracy.

关键词： Radio frequency identification (RFID)  

摘要： A nested octagon passive chipless radio frequency identification (RFID) tag with an encoding capacity of 12 bits has polarization diversity and 1:1 slot-to-bit correspondence. Its compact 23 x 23 mm footprint yields a bit density of 2.26 bits/cm(2). The tag is fabricated on a flexible Rogers RT/duroid 5880 laminate.

关键词： Machinery  

摘要： RFID technology can help manufacturers control access to critical hardware and software. What’s the best way to ensure product quality and production uptime in industrial automation? Make sure that only trained and authorized people can access the programmable controllers. A typical assembly plant is equipped with an assortment of machinery and robots to fabricate and assemble various products.

关键词： RFID   excess inventory   revenue‐   cost‐   sharing contract   retail supply chain   bargaining game   wholesale‐   price contract  

摘要： This paper considers a supply chain consisting of one supplier and one retailer who jointly invest in item-level radio frequency identification (RFID) by considering their demands and inventories. Since the supplier can be negative to adopt RFID, the main objective of this study is to design an effective mechanism that maximizes the profits of both players and the whole supply chain by implementing item-level RFID. For this objective, we propose a novel revenue-cost-sharing (RCS) contract based on the bargaining game as the incentive to encourage the implementation, and numerical results show that the RCS contract is considerably more effective than the wholesale-price contract for supply chain coordination. Moreover, we show that the retail supply chain can be coordinated perfectly under the RCS contract when the thresholds of the revenue/cost sharing rates are set appropriately. This study provides significant managerial insight into the incentive and coordination strategy to implement item-level RFID in the retail supply chain.

关键词： Wireless communication   Wireless sensor networks   Plants (biology)   Soil   Agriculture   Sensors   Intelligent sensors  

摘要： With the advent of emerging technologies, traditional agriculture practices are now shifting towards the “smart” approach. Smart agriculture aims to automate most aspects of the plant growing process to save the labor and improve the efficiency, the yield and quality of the crops/harvest. In recent years, Radio Frequency Identification (RFID) sensing technology has emerged and unleashed a new series of applications in the field of agriculture. This paper first introduces RFID sensing technology, then surveys its applications to the four areas of agriculture: plant growing environment, soil conditions, plant growth, and the quality of the harvests. The paper aims to identify the uniqueness of RFID sensing technology in solving agriculture issues and its limitations.