Dual-band Radio Frequency Identification Research Articles

Front-End Rectifier of Self-Compensation Matching with Parasitic Cancellation for Dual-Band RFID Tag

This paper presents an innovative cross-coupled differential drive rectifier for dual-band Radio frequency identification (RFID) tags. A self-compensating rectifier with enhanced power-conversion efficiency (PCE) at low and high RF power is proposed. The proposed rectifier utilizes a self-compensating circuit, the extra two cross-couple transistors, to increase the gate voltage of transistors to control the conduction of the rectifying transistors. In order to adapt high frequency (HF) and ultrahigh frequency (UHF) rectification, the matching circuit is designed with parasitic cancellation technology. Moreover, the cascading power management circuits are added to generate a stable output voltage. The multi-standard rectifier is designed and simulated in [Formula: see text] CMOS process. The simulated result shows that the proposed three-stage rectifier achieves a PCE 74% (at [Formula: see text] load) when receiving a 915[Formula: see text]MHz signal with average power of [Formula: see text]. Moreover, the maximum efficiency achieves 56% at HF 13.56[Formula: see text]MHz, and the final output voltage can be stabilized at a specific voltage of 1.052[Formula: see text]V.

MSCNN-LSTM Model for Predicting Return Loss of the UHF Antenna in HF-UHF RFID Tag Antenna

High-frequency (HF) and ultrahigh-frequency (UHF) dual-band radio frequency identification (RFID) tags with both near-field and far-field communication can meet different application scenarios. However, it is time-consuming to calculate the return loss of a UHF antenna in a dual-band tag antenna using electromagnetic (EM) simulators. To overcome this, the present work proposes a model of a multi-scale convolutional neural network stacked with long and short-term memory (MSCNN-LSTM) for predicting the return loss of UHF antennas instead of EM simulators. In the proposed MSCNN-LSTM, the MSCNN has three branches, which include three convolution layers with different kernel sizes and numbers. Therefore, MSCNN can extract fine-grain localized information of the antenna and overall features. The LSTM can effectively learn the EM characteristics of different structures of the antenna to improve the prediction accuracy of the model. Experimental results show that the mean absolute error (0.0073), mean square error (0.00032), and root mean square error (0.01814) of the MSCNN-LSTM are better than those of other prediction methods. In predicting the return loss of 100 UHF antennas, compared with the simulation time of 4800 s for High Frequency Structure Simulator (HFSS), MSCNN-LSTM takes only 0.927519 s under the premise of ensuring prediction accuracy, significantly reducing the calculation time, which provides a basis for the rapid design of HF-UHF RFID tag antenna. Then MSCNN-LSTM is used to determine the dimensions of the UHF antenna quickly. The return loss of the designed dual-band RFID tag antenna is and at 13.56 and 915 MHz, respectively, achieving the desired goal.

Secure Lightweight IoT Integrated RFID Mobile Healthcare System

Patient safety is a global public health concern nowadays, especially in elderly people who need physiological health monitoring systems integrated with a technology which will help to oversee and manage the medical needs. In this direction, we propose a lightweight effective healthcare monitoring system designed by using the Internet of Things (IoT) and Radio Frequency Identification (RFID) tags. In this technique, we use dual-band RFID protocols which are the one working at a high frequency of 13.56 MHz and useful to figure out the individuals, and 2.45 GHz microwave bands are used to monitor corporal information. Sensors are used to monitor and collect patient physiological data; RFID tag is used to recognize the patient. This IoT-based RFID healthcare monitoring system provides acquisition of physiological information of elderly people and patients in hospital. Further, it is aiming to secure patient’s health recordings using hyper elliptic curve- (HEC-) based signcryption algorithm while allowing the doctor to access patient health information. Privacy is provided to variable length patient medical records using different genus curves, and the evaluation shows that the proposed algorithm is optimal with respect to healthcare.

Dual Band RFID-Based Blood Glucose Monitoring System in Wireless Sensor Network Platform

Accurate record on the patient’s glucose information is crucial to assist doctors in decision making and prescribing correct medication. In this paper, a dual band Radio-Frequency Identification (RFID) system embedded with glucose meter was developed by integrating a 920 MHz passive interrogator into the 2.45 GHz active tag to enable automatic patient detection, wireless data recording and monitoring in dense hospital environment with frequent usage. The real-time experimental results indicate that the developed embedded RFID system in the multihop wireless sensor network is able to maintain the integrity of the glucose data according to the identification of the patient until the data are successfully recorded to the remote host system. Design of Experiment method is performed to determine the factors that influenced the throughput performance of the system. Comparisons made between existing non-embedded RFID system and the proposed embedded RFID system. The three factors investigated were the packet length, number of hops and type of RFID. The statistical analysis showed that the packet length as the main factor influencing the throughput performance. The results showed that the larger packets increase the throughput, while the number of hops contributes more to the decreasing effect of the throughput compared to the implementation of embedded RFID system.

Compact and High-Gain UHF/UWB RFID Reader Antenna

A linearly polarized, dual-port, and dual-band radio frequency identification reader antenna is designed to simultaneously operate at ultrahigh frequency (UHF) and ultra-wideband bands for positioning systems. A hybrid design using patch and slot structures within a shared radiating aperture is proposed and demonstrated to achieve a high gain and wideband operation with a limited profile. The size of the total antenna is 200 mm × 10 mm. The measured impedance bandwidth of the UHF antenna ranges from 0.890 to 0.907 GHz with a minimum antenna gain of 9 dBi. The measured impedance bandwidth of the ultra-wideband antenna can cover the frequency band from 3 to 4.99 GHz with a minimum antenna gain of 9 dBi. The antenna gains near two WLAN bands are less than -15 dBi at 2.45 GHz and -5 dBi at 5.8 GHz, respectively. The mutual coupling between the two ports is less than -30 dB over the two bands.

HF/UHF dual band RFID transponders for an information-driven public transportation system

The limited communication range of HF radio frequency identification (RFID) smart cards does not allow to automatically assess the alighting point of passengers on public transportation. This work considers HF/UHF dual band RFID transponders for electronic ticketing in an information-driven public transportation system. The UHF RFID interface is intended to enable a remote detection of passengers inside a vehicle and thus to assess the alighting point of passengers. A review of the specific operating conditions for the UHF RFID link is given and associated privacy issues are addressed. We introduce a low-complexity approach to safeguard the privacy of passengers. Following a discussion of the architecture of appropriate HF/UHF dual band transponder ICs, the focus is set on questions of the circuit implementation. With regard to the progressing CMOS technology scaling, we can observe potential risks of overvoltage stress for the UHF RFID front-end at high input powers. Two RF voltage limiters that prevent overvoltages are presented. Experimental results of circuit prototypes in a 40 nm CMOS technology demonstrate the functionality of two UHF RFID front-ends that incorporate the RF voltage limiters.

Dual‐band RFID tag antenna based on the Hilbert‐curve fractal for HF and UHF applications

A novel single-radiator card-type tag is proposed which is constructed using a series Hilbert-curve loop and matched stub for high frequency (HF)/ultra high frequency (UHF) dual-band radio frequency identification (RFID) positioning applications. This is achieved by merging the series Hilbert-curve for implementing the HF coil antenna, and square loop structure for implementing the UHF antenna to form a single RFID tag radiator. The RFID tag has directivity of 1.75 dBi at 25 MHz, 2.65 dBi at 785 MHz, 2.82 MHz at 835 MHz and 2.75 dBi at 925 MHz. The tag exhibits circular polarisation with −3 dB axial-ratio bandwidth of 14, 480, 605 and 455 MHz at 25, 785, 835 and 925 MHz, respectively. The radiation characteristics of the RFID tag is quasi-omnidirectional in its two orthogonal planes. Impedance matching circuits for the HF/UHF dual-band RFID tag are designed for optimal power transfer with the microchip. The resulting dual-band tag is highly compact in size and possesses good overall performance which makes it suitable for diverse applications.

An intelligent health monitoring system using radio-frequency identification technology.

Long-term care (LTC) for the elderly has become extremely important in recent years. It is necessary for the different physiological monitoring systems to be integrated on the same interface to help oversee and manage the elderly's needs. This paper presents a novel health monitoring system for LTC services using radio-frequency identification (RFID) technology. Dual-band RFID protocols were included in the system, in which the high-frequency (HF) band of 13.56 MHz was used to identify individuals and the microwave band of 2.45 GHz was used to monitor physiological information. Distinct physiological data, including oxyhemoglobin saturation by pulse oximetry (SpO2), blood pressure, blood sugar, electrocardiogram (ECG) readings, body temperature, and respiration rate, were monitored by various biosensors. The intelligent RFID health monitoring system provided the features of the real-time acquisition of biomedical signals and the identification of personal information pertaining to the elderly and patients in nursing homes.

A Compact Dual-Band RFID Tag Antenna Mountable on Metallic Objects

A compact (50 × 50 × 4 mm3) dual-band radio frequency identification (RFID) tag antenna mountable on metallic objects is proposed for the ultra-high frequency (UHF) band (917∼923.5 MHz) and the microwave (MW) band (2.4∼2.45 GHz). With the proximity-coupled feed loop, the proposed antenna consists of two symmetric planar inverted-F antenna (PIFA) elements for the UHF band passive tag and a meander microstrip patch antenna for the MW band active tag. The performance of the proposed antenna is verified by mounting it on the different sizes of the metallic object. Furthermore, the passive tag antenna in the UHF band furthermore may be used for energy harvesting techniques to improve the lifetime of the active tag in the MW band. The measured maximum read range is 5.50 m in the UHF band and 14.15 m in the MW band when the proposed tag antenna is mounted on the metallic objects. The total efficiency for all operating frequency bands is higher than 50%. High isolation (>12 dB) between tag antennas in the UHF band and the MW band is achieved.

Analysis and exploitation of harmonics in wireless power transfer (H-WPT): passive UHF RFID case

This paper discusses novel methodologies for the characterization of harmonic signals generated by wireless powered devices, i.e. passive ultra-high frequency (UHF) radio frequency identification (RFID) tags, due to the wireless power transferred from reader to tag. Theoretical aspects, as well as measurements to characterize these non-linear phenomena are exposed. Particular care is taken to explain the analysis methodology and setup for two kinds of characterization measurements: radiated and conducted. The existence of harmonic signals carrying information is exploited in an advanced application example. A dual-band RFID tag is designed to increase the backscattered harmonic level in the tag-to-reader link. Measurement of this dual band tag demonstrates the exploitation of the hitherto neglected harmonic power; it also opens the door to more advanced applications exploiting the harmonic-link communication.

A Novel Dual-Band Tag Antenna for RFID Application

With the rapid development of RFID (radio frequency identification) application, the design requirements of RFID tag antenna are also increasing. A design of dual-frequency or multi-frequency tag antenna has become fashionable. In the present paper, we design a dual-band RFID tag antenna, which consists of a bent microstrip patch and rectangular microstrip patch. The designed antenna is analyzed and optimized by HFSS13. Simulation results indicate that the tag antenna has the characteristics of double band, high gain, and good radiation pattern.

Dual-Band Antenna/AMC Combination for RFID

A novel antenna/Artificial Magnetic Conductor (AMC) combination usable in dual-band Radio Frequency Identification (RFID) tags over metallic objects is presented. A compact and low thickness prototype is manufactured and characterized in terms of return loss and radiation properties in an anechoic chamber both alone and on a metallic plate. The performance exhibited by the presented antenna/AMC prototype is proper for RFID tags on both metallic and nonmetallic objects.