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关键词： 2.45 GHz   circular polarization   RFID  

摘要： In this article, an innovative design of a broadband circularly polarized compact planar antenna for RFID (radio frequency identification) receivers is presented. The suggested structure used the concept of slots loaded parasitic element printed underneath a coplanar waveguide-fed radiator to achieve the circularly polarized (CP) radiation and size reduction. A parasitic element loaded with F-slot and L-slot, and a window-type slotted ground plane was used to achieve resonance at 2.45 GHz with right-handed circularly polarized radiation for RFID handheld reader application. Experimental results confirmed that the designed antenna of size 16.5 x 14.8 x 1.6 mm(3) attained a -10 dB impedance bandwidth of 15.8% (from 2.330 to 2.716 GHz) and 3 dB AR bandwidth of 3.43% (from 2.410 to 2.494 GHz). An axial ratio of 0.43 dB was achieved in the boresight of the antenna at the 2.45 GHz RFID band. The concept of electric field distribution on the antenna was used to elaborate the excitation of CP radiation in the antenna.

关键词： Chipless RFID tags   dielectric materials and polymers   effective permittivity   inkjet printing   RCS   RQF  

摘要： A five-slot hexagonal shape chipless RFID tag is designed, simulated, and manufactured on FR4 substrate. The designed tag's copper geometry was replicated on a wide range of dielectric substrate to quantify the impact on resonance quality factor (RQF) and resonating frequencies. The tag's performance was assessed in three configurations. First, a hexagonal shape tag's radar cross section (RCS) was studied over different dielectric substrates. The various dielectric substrate effects were investigated over the maximum read range, resonant frequencies and RQF. In the second evaluation, the physical geometry of the tag was adjusted to achieve the spectral signatures in 2-7 GHz frequency band with high RQF. In step three, the optimized tag geometry was manufactured on FR4, Roger Duroid 5880, and polyethylene naphthalate (PEN) substrates. Denford milling machine for PCB engraving and inkjet printing for silver nanoparticles deposition were used for tags manufacturing. During tag manufacturing, copper and silver were used as conducting materials for RCS backscattering. The tag RCS response was measured by vector network analyzer with bi-static antenna setup. The analysis of different dielectric substrate provides a pathway of designing a novel substrate by using various nanomaterials.

关键词： adjustable reading area   near-field   radio-frequency identification   reader antenna   wideband  

摘要： A universal ultrahigh-frequency (UHF) near-field radio-frequency identification (RFID) reader antenna with wide bandwidth and adjustable reading area is proposed in this letter. The antenna consists of an inverting power splitter base on double-sided parallel stripline and adjustable traveling-wave near-field radiation units, which consists of two symmetrical meander microstrips and a complementary open resonant ring loaded on the ground plane. A design example with three radiation units is simulated, fabricated, and tested for verification. The result indicates that the proposed antenna has the 10-dB impedance bandwidth of 128%, which completely covers the universal UHF RFID band from 840 to 960 MHz. The 100% read-write rate is achieved within the read-write distance of 10 mm according to the reading test. The reading area of 731 x 120 mm(2) can be obtained for increasing the number of radiation units to 10. Moreover, the antenna features low far-field gain, low-cost, strong and uniform magnetic field distribution. Therefore, the proposed antenna and design method have good application prospects in the Internet of Things.

关键词： Big Data Analytics   RFID   Production System   Manufacturing Big Data  

摘要： Radio Frequency Identification (RFID) technology has been widely implemented in manufacturing shop-floors to collect production data, which in turn can be used for making decisions, analyzing production efficiency and evaluating aspects of a product's quality evaluation. The RFID-collected manufacturing Big Data can reflect the real-time statuses of all manufactured products and production processes. This paper introduces an analytical method to examine the RFID-collected manufacturing Big Data. Specifically, the proposed method includes four key steps: data cleansing, data processing, data visualization and data analytics. This systematic method enables small- and medium-sized enterprises (SMEs) to perform data analytics in a simple manner. Production efficiency analysis is investigated and associated with operators, processes, and machines respectively. It is observed that error rates and performance bottlenecks can be attributed to a variety of factors such as machine failure, process deficiencies, and human error.

关键词： RFID   sensor networks   mobile sensor   static sensor   marine environments   data reception   monitoring  

摘要： This paper is focused on the use of radio frequency identification (RFID) technology operating at 125 kHz in a communication layer for a network of mobile and static nodes in marine environments, with a specific focus on the Underwater Internet of Things (UIoT). The analysis is divided into two main sections: characterizing the penetration depth at different frequencies and evaluating the probabilities of data reception between antennas of static nodes and a terrestrial antenna considering the line of sight (LoS) between antennas. The results indicate that the use of RFID technology at 125 kHz allows for data reception with a penetration depth of 0.6116 dB/m, demonstrating its suitability for data communication in marine environments. In the second part of the analysis, we examine the probabilities of data reception between static-node antennas at different heights and a terrestrial antenna at a specific height. Wave samples recorded in Playa Sisal, Yucatan, Mexico, are used for this analysis. The findings show a maximum reception probability of 94.5% between static nodes with an antenna at a height of 0 m and a 100% data reception probability between a static node and the terrestrial antenna when the static-node antennas are optimally positioned at a height of 1 m above sea level. Overall, this paper provides valuable insights into the application of RFID technology in marine environments for the UIoT, considering the minimization of impacts on marine fauna. The results suggest that by adjusting the characteristics of the RFID system, the proposed architecture can be effectively implemented to expand the monitoring area, considering variables both underwater and on the surface of the marine environment.

关键词： Backscatter radio   RFID   Gen2   reconfigurable surface  

摘要： This work exploits ultra-low cost, commodity, radio frequency identification (RFID) tags as elements of a reconfigurable intelligent surface (RIS). Such batteryless tags are powered and controlled by a software-defined radio reader, with properly modified software, so that a source-destination link is assisted, operating at a different band. Signal model includes small-scale and large-scale fading, direct link, as well as specific parameters relevant to reflection (i. e., backscatter) radio, such as antenna structural mode and reflection efficiency, typically overlooked in the literature. An algorithm is offered that computes the optimal RIS configuration with complexity of O( M logM) in number of elements M, instead of intractable exponential complexity of exhaustive search, while accommodating any number K >= 2 of loads. With the proposed algorithm, it is shown that performance gains reach a plateau for constant element spacing and increasing number of elements, suggesting that the weak, passive nature of backscattered links limits the performance gains, even with perfect channel estimation. Channel estimation with linear minimum mean squared error (LMMSE) estimator is shown to be effective, provided that there are sufficient number of pilot symbols. A concrete way is offered to design and prototype a wireless, batteryless, RF-powered, reconfigurable surface and a proof-of-concept is experimentally demonstrated.

关键词： Deep learning   Alphabet RFID   Chipless RFID   Arabic letter RFID   LSTM  

摘要： This work demonstrates a novel approach for reliable and robust identification and detection of realized chipless RFID Arabic alphabets using deep learning (DL) method. The undertaken classification problem of Arabic RFID tags of various fonts and sizes requires a classification technique that can learn long-term dependencies. Hence, a Bi-Long Short-Term Memory (BiLSTM) model is developed to classify 28 chipless Arabic RFID letters of different font types and sizes using their back scattered dual-polarized radar cross section (RCS) characteristics. The RCS frequency response of each Arabic letter tag reflects its signature electromagnetic characteristics that vary with the change in its shape (variations in font type and size). Firstly, an RCS dataset of 28 Arabic alphabet tags with three different font types (Arial, Calibri, and Times New Roman) and 13 different font sizes (16 mm-28 mm with a step size of 1 mm) are generated using Finite-Difference Time -Domain (FDTD) method in the frequency range of 1-12 GHz (1001 steps). The dimensions of the resulting dataset are [28 (letters) x 13 (font sizes) x 1001 (frequency steps) x 2 (polarizations)] x 3 (font types). Multi -class classification of the frequency-series data of all realized 28 alphabet tags of various font types and sizes makes the problem challenging and novel. The developed BiLSTM model can accurately classify the particular letter tag with specific font type and size based on the optimized network with employed Leave-One-Out Cross-Validation (LOOCV). The achieved accuracy with only Arial ([(28 x 13 x 1001 x 2)]), Calibri ([(28 x 13 x 1001 x 2)]), Times New Roman ([(28 x 13 x 1001 x 2)]), and combined data set ([(28 x 13 x 1001 x 2)] x 3) is 75%, 74%, 75%, and 89% respectively. The proposed Bi-LSTM model is shown superior when compared to other methods such as SVM, decision trees, and KNN, as it classifies the data with much higher accuracy for the considered multi-class data. The obtained accuracies of t

关键词： Localisation   RFID   Non -palpable   Breast cancer  

摘要： Aim: The purpose of this study is to report the surgical experience and outcomes with pre-operative localisation of non-palpable breast lesions using the RFID tag ***: The cohort for this prospective study included patients over the age of 18 with biopsy proven, non -palpable indeterminate lesions, DCIS or breast cancer requiring pre-operative localisation before surgical exci-sion between September 2020 and July ***: A total of 312 RFID tags were placed in 299 consecutive patients. Indications for localisation included non-palpable invasive cancer in 255 (85.3%) patients, in situ disease in 38 (12.7%) and indeterminate lesions requiring surgical excision in 6 (2.0%). Both in situ and invasive lesions had a median size of 13 mm (range 4-100 mm) on pre-operative imaging. The RFID tags were in situ for a median time of 21 days before surgery (range 0-233 days). Of the 213 tags, 292 (93.6%) were introduced using ultrasound (USS) guidance and ster-eotactically in 20 (6.4%). In 3 (1.0%) cases the RFID tag was either not satisfactorily deployed at the intended target or retrieved intra-operatively. Following discussion of post-operative histology by the multi-disciplinary team, further surgery for close or involved margins was for 26 (8.7%) ***: The Hologic RFID tag system can be used for accurate pre-operative localisation of non-palpable masses as well as diffuse abnormalities such as mammographic distortions and calcifications. It has advan-tages of flexibility for scheduling image-guided insertion independently of scheduled operating lists and can be placed to localise lesions prior to initiating neoadjuvant systemic treatment.

关键词： Radar cross section  

摘要： In the realm of radio frequency identification (RFID) technology, the integration of reconfigurable intelligent surfaces (RISs) has opened up new possibilities for real-time remote data capturing and seamless connectivity. By manipulating the electromagnetic properties of the environment, RIS enables the control of electromagnetic wave propagation and allows for virtual line-of-sight (LOS) in cases where physical LOS is blocked. This has tremendous implications for the future of RFID applications, particularly with the emergence of chipless RFID technology. In this regard, this paper develops free-space path loss models for RIS-assisted RFID wireless communications. The proposed models in this study have taken into account several crucial physical factors, including tag radar cross-section (RCS), the physical properties of the RIS, and the near-field/far-field effects of the RIS. To further validate the theoretical findings, we have conducted experimental measurements using a fabricated RIS. Numerical simulations were also utilized to validate the models and verify our findings. The channel measurements have demonstrated good agreement with the proposed path loss models, further bolstering the potential of RIS-assisted RFID wireless communications. © 2023, CC BY.

摘要： In this paper, New passive UHF RFID antenna using uniform meander line antenna theory is presented as a contribution for RFID TAG antenna field. This RFID TAG antenna is designed on kapton substrate having a dielectric constant of 3.5, tangent loss of 0.0027 and height of 508um. The RFID TAG antenna is designed and simulated using an electromagnetic solver. The proposed RFID TAG antenna is designed to cover the UHF band [865-870MHz] with a bandwidth of 5MHz, the reflection coefficient is around - 14.96dB at 868MHz, simulated gain is equal to 1.66dBi and a theorical read range of 7m, the designed antenna is validated, manufactured using the ink-jet process on kapton and assembled using anisotropic conductive paste. The whole area of the RFID TAG antenna is 40×50mm2 with experimental read range of 6 m confirmed by a reading test using an RFID base station.