Tag Antenna Design Research Articles

Research on U-shaped tuning stub RFID tag on different objects

A new ultra-high frequency radio frequency identification (RFID) tag antenna, which is comprised a U-shaped tuning stub and a dipole radiator for different permittivity surfaces is investigated, fabricated, and measured. For a conjugate match to the NXP G2XM chip impedance of 29–j137 at 915 MHz, a dipole tag antenna with U-shaped stubconnected to dipole arms was designed. Simple size adjustments of the U-shaped tuning stub and dipole radiator of the antenna allow for easy control of the antenna resistance and inductive reactance, from which the chip impedance requirement may be readily satisfied. The read range of the prototype antenna attached on a different permittivity surfaces (εr= 1–4) can reach more than 4.5 m, which has been tested for an RFID reader with 4.0 W of effective isotropic radiated power. The antenna structure consists of two dipole load bars and two loop electrically connected. The design offers more choice of freedom to tune the input impedance of the proposed antenna. Measurement data are presented which are in good agreement with simulation results. The design is suitable for mounting on all kinds of objects. The fabricated tag sensitivity of −3 dBm, read range of 7 m on the x–z and y–z planes, and the measured orientation radiation patterns were obtained in the desired frequency band.

An Inverted L Antenna with a Parasitic Structure for RFID Tag

An inverted L antenna altered by a parasitic resonant structure is designed for RFID tag. In order to determine the performance of varying design parameters on impedance and resonance frequency, HFSS simulation software and experimental tests are carried out. This way, the focus of this work is RFID tag antenna design based on the structure above mentioned.

An Inverted L Antenna with a Parasitic Structure for RFID Tag

An inverted L antenna altered by a parasitic resonant structure is designed for RFID tag. In order to determine the performance of varying design parameters on impedance and resonance frequency, HFSS simulation software and experimental tests are carried out. This way, the focus of this work is RFID tag antenna design based on the structure above mentioned.

Circularly Polarized Broadband RFID Microstrip Tag Antenna

In recent years, the application of radio frequency identification (RFID) operating in the ultra-high frequency (UHF ) band (860-960MHz) are expanding exponentially, due to the advantages such as long reading distance, high data transfer rate, and small tag size. So the design of a CP tag antenna with broadband characteristic is presently one of the most challenging topics. This project presents a square patch passive RFID tag antenna designed for UHF band. To achieve compact size broadband and circular polarization (CP) radiation, the square patch is embedded with a cross slot, while an L-shaped open-end microstrip line coupled to the patch. By selecting an appropriate length for the microstrip line and its coupling distance with the radiating element, easy control on the input impedance of t he designed tag antenna which leads to excellent impedance matching is achieved. The measured 10-dB return-loss bandwidth of the tag antenna is 27MHz (from 901-928 MHz).

Design and Analysis of UHF RFID Tag Antenna on the Surface of Cylinder

Cylinder is a common object and used in logistics industry, such as liquid container like wine. The performance of tags that are used on these objects declines, especially the read range and the radiation pattern of the tag. In this paper, a type of UHF tag antenna directly mountable on the cylinder surface. In order to reduce the impact of the deformation, the tag is designed with meander-line but not symmetrical. Antenna is combined with T-matching network to ensure good impedance matching. Compared with the basic dipole antenna tag both cylinder and plane surface, we can get the prominent feature of the tag proposed in this paper.

A Miniature Antenna for 2.45 GHz RFID Tag

On the basic of fractal theory and folded technique, a miniature antenna for 2.45 GHz radio frequency identification (RFID) tag applications is designed and analyzed in the present paper. In order to realize the miniaturization of tag antenna, a Hilbert fractal structure is used. Impedance matching between antenna and IC chip is of great importance for improving tag performances. A folded technique is employed to achieve impedance matching flexibly. The value of input impedance of tag antenna can be varied readily only by tuning the high of folded line. The dimensions for the designed tag antenna at 2.45GHz are 23.32mm×7.66mm, and its return loss, bandwidth, and gain are analyzed by HFSS. The detection distance is estimated by Friis transfer theory. Analysis results demonstrate that the tag antenna designed in this paper may satisfy the requirements of RFID tag applications.

Novel Spiral Antenna Design Using Artificial Bee Colony Optimization for UHF RFID Applications

In this letter, a new planar spiral antenna for passive radio frequency identification (RFID) tag application at UHF band is designed and optimized using the Artificial Bee Colony (ABC) algorithm. The optimization goals are antenna size minimization, gain maximization, conjugate matching, and in consequence the maximization of the read range. The antenna dimensions were optimized and evaluated using ABC in conjunction with commercial electromagnetic (EM) software. The comparison of the results obtained by ABC to respective ones of other popular evolutionary algorithms show that ABC can be efficiently applied to tag antenna design problems. To validate the theoretical results, designed RFID tags were fabricated, and their reading efficiency was evaluated experimentally. The results of simulation and those received via measurements prove that the proposed method for the design of passive RFID tag antennas is efficient, as antennas with dimensions less than 3 cm, gain that reaches the value of 1.6 dBi, and read range about 6 m were obtained.

Design of Miniature Implantable Tag Antenna for Radio-Frequency Identification System at 2.45GHz and Received Power Analysis

SUMMARY In recent years, there has been rapid developments in radio-frequency identification (RFID) systems, and their industrial applications include logistics management, automatic object identification, access and parking management, etc. Moreover, RFID systems have also been introduced for the management of medical instruments in medical applications to improve the quality of medical services. In recent years, the combination of such a system with a biological monitoring system through permanent implantation in the human body has been suggested to reduce malpractice events and ameliorate the patient suffering. This paper presents an implantable RFID tag antenna design that can match the conjugate impedance of most integrated circuit (IC) chips (9.3 − j55.2 Ω at 2.45 GHz. The proposed antenna can be injected into the human body through a biological syringe, owing to its compact size of 9.3 mm × 1.0 mm × 1.0 mm. The input impedance, transmission coefficient, and received power are simulated by a finite element method (FEM). A three-layered

A NOVEL UHF RFID SLOT COUPLED METALLIC TAG ANTENNA FOR STEEL-BAR APPLICATIONS

In this paper, we propose a novel UHF RFID coupled slot metallic tag antenna with a radome. The proposed tag antenna consists of a frequency tuning slot, imaginary part tuning slot, real part tuning stub, micro-chip, and radome. The RFID tag antenna was designed and fabricated for use in the Korean and Japanese UHF band of 916.7 to 923.5MHz. The measured 3dB frequency bandwidth is 914 to 926MHz. The measured read range is 11.5m on a metallic surface. Details of the proposed tag antenna design, as well as simulated and measured results are presented and discussed.

RFID Technology and Applications

RFID is emerging as one of most fundamental technologies to Internet of Things due to its attractive features such as good reading ranges, high data rates, and low cost. RFID has achieved a widespread success in various applications, ranging from asset tracking, highway toll collection, supply chain management, animal identification to surveillance systems. Moreover, there has been a wide scope of development in RFID standards, protocols, and middleware. However, a series of challenging issues should be properly addressed before a massive adaptation of RFID technology. In this special issue, we have received 24 paper submissions and accepted 9 papers finally according to the reviewers’ comment and associate editors’ suggestion. These accepted papers include RFID reader antenna design, RFID tag antenna design, RFID passive transponders, tag collision algorithm, and RFID application systems. B. Lee et al. from Kwangwoon University of Korea proposed a novel structure of an NFC loop antenna for mobile handset applications by improving the performance of an NFC loop antenna when a ferrite-polymer composite is attached between the embedded NFC loop antenna and the phone battery. The proposed loop antenna gives better performance than that of a conventional NFC loop antenna. L. X. Zheng et al. from South China University of Technology proposed a compact RFID reader antenna for UHF near-field and far-field operations. The structure of the antenna is a novel folded-dipole loop and is formed by a concentric metal ring with a split. It can provide uniform magnetic near-field distribution and available farfield gain. Y. Yao et al. from Beijing University of Posts and Telecommunications also proposed a novel RFID reader antenna. This antenna was fabricated using indium tin oxide film; thus, it has optically transparent characteristic.This kind of antenna can be used in clothing stores. P. Jankowski-Mihulowicz et al. from Rzeszow University of Technology proposed novel RFID passive transponders with additional energy harvester. They can recover energy from the electromagnetic field of read device and the harvested energy was utilized to supply a microprocessor acquisition block for developed LTCC pressure sensor. C. Wang et al. from Beijing University of Posts and Telecommunications proposed an advanced dynamic framed-slotted ALOHA algorithm based on Bayesian estimation and probability response to solve the tag collision problem of RFID system. The simulation results show that the proposed algorithm has better performance. We sincerely hope that this special issue can further help the readers to understand RFID antenna design and applications and explore the future development of the system.

Design of a Tag Antenna for UHF RFID Food Systems

This paper proposes a tag antenna for radio frequency identification (RFID) food system. The RFID tag antenna is designed and fabricated based on the rectangular loop concept used in the UHF band (Korean and Japanese standards, 916.7-923.5MHz). The proposed tag antenna is composed of a radiation patch, sensor tag chip, temperature sensor, oscillator, and battery. We conjugated matching between the tag antenna and the sensor tag using a U-shaped stub. Details of the proposed tag antenna design and the simulated and measured results are presented and discussed.

Broadband UHF RFID tag antenna design matched with different RFID chips

ABSTRACTA novel antenna structure with two crab‐shaped patches and a small microstrip dipole is proposed for ultra frequency radio frequency identification (RFID) tag design, which can be directly integrated in metallic plates or other objects. The feature of the design is that the tag antenna can operate effectively with different ultrahigh frequency (UHF) RFID chips, and the design of the conjugate impedance match of the RFID tag can be easily obtained. The important advantages of the antenna structure are that the tag does not have to be redesigned to work with different RFID chips. The antenna's size is 45 mm × 75 mm × 0.5 mm. The antenna achieves 200 MHz bandwidths, which covers worldwide UHF RFID bands (840–960 MHz). Furthermore, the proposed antenna obtains high gains and a good radiation pattern. The simulated and measured results are shown to be in good agreement with each other. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:55–57, 2014

A Simple Equivalent Circuit for Small RFID Tag Antennas in Low Loss Dielectric Materials

Small radio frequency identification (RFID) tag antennas are generally designed to achieve conjugate matching with capacitive chips at the called tag resonant frequency. An approximate equivalent circuit is proposed to represent the antenna input impedance in low loss dielectric materials. It consists of a shunt conductance considered to be linearly proportional to loss tangent, an input resistance and reactance of antenna in lossless materials. Comparing with the simulated result of full wave numerical tool, the equivalent circuit gives acceptable errors in input resistance and reactance at the tag resonant frequency and nearby. The simple equivalent circuit can be used to reduce the repetitive simulation work for different loss tangent.

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.

A Folded RFID Tag Antennas Based on Hilbert Fractal Structure

Based on Hilbert theory and technique, a folded tag antenna for RFID application is presented in this paper. In order to reduce the size of tag, a Hilbert fractal structure is employed. Additionally, to match flexibly the impedance between antenna and chip, a folded technique is employed. The input impedance of tag antenna can be adjusted easily by changing the high of folded structure. A designed tag antenna dimension is 23.32mm×7.66mm, and its return loss, bandwidth, gain and theoretical detection distance are given at 2.45GHz by HFSS software. The simulation results show that the designed antenna can meet the requirements of the practical applications.

Automated Identification of Plywood Using Embedded Inkjet-Printed Passive UHF RFID Tags

The use of passive ultra high-frequency (UHF) radio frequency identification (RFID) integrated into plywood boards is proposed to enable the identification and tracking of individual plywood boards and end products of plywood. For the first time, tags are embeddable inside plywood by direct inkjet-printing tag antennas on pure birch veneer. The use of passive UHF RFID technology in the applications of plywood industry is discussed, two tag antenna designs for plywood are presented and the tag fabrication procedures are described. Furthermore, results from tag performance measurements performed in the authentic application environment as well as in anechoic conditions are presented and discussed. Measurements show that tags printed on veneer and embedded inside 2 mm thick plywood board exhibited theoretical read ranges from 7.9 to 10.1 meters. The read ranges obtained meet the demands of the plywood industry and offer reliable identification even in challenging environments.

Chipless RFID tags fabricated by fully printing of metallic inks

This paper reviews recent advances in fully printed chipless radio frequency identification (RFID) technology with special concern on the discussion of coding theories, ID generating circuits, and tag antennas. Two types of chipless tags, one based on time-domain reflections and the other based on frequency domain signatures, are introduced. To enable a fully printed encoding circuit, linearly tapering technique is adopted in the first type of tags to cope with parasitic resistances of printed conductors. Both simulation and measurement efforts are made to verify the feasibility of the eight-bit fully printed paper-based tag. In the second type of tags, a group of LC tanks are exploited for encoding data in frequency domain with their resonances. The field measurements of the proof-of-concept of the tag produced by toner-transferring process and flexible printed circuit boards are provided to validate the practicability of the reconfigurable ten-bit chipless RFID tag. Furthermore, a novel RFID tag antenna design adopting linearly tapering technique is introduced. It shows 40 % save of conductive ink materials while keeping the same performance for conventional half-wave dipole antennas and meander line antennas. Finally, the paper discusses the future trends of chipless RFID tags in terms of fabrication cost, coding capacity, size, and reconfigurability. We see that, coupled with revolutionary design of low-cost tag antennas, fabrication/reconfiguration by printing techniques, moving to higher frequencies to shrink tag sizes and reduce manufacturing cost, as well as innovation in ID generating circuits to increase coding capacities, will be important research topics towards item-level tracking applications of chipless RFID tags.

UHF RFID Tag Antenna for Vehicle License Plate Number (e-Plate)

In this research presents a new design of UHF RFID tag antenna for vehicle license plate number (e-plate). The proposed e-plate does not require another gadget or equipment since every vehicle is attached with a vehicle registration plate number and this e-plate embedded together. A low cost FR4 material has been used for its fabrication and there is performance improvement compared to the current tag antenna. The proposed antenna design works at 902-928 MHz frequency band for UHF RFID application with 3.8 dBi antenna gain. The antenna is rectangular in shape and has a dimension of 300 mm x 100 mm, which is usually the typical size of the conventional vehicle registration plate number. Acceptable responses were obtained in simulation at centre frequency of 915 MHz with reflection coefficient of -57.7 dB. The performance of proposed e-plate antenna was further tested by attaching a RFID tag chip and embedded it to the actual vehicle plate number. Initial testing on the field by attached e-plate on vehicle was achieved maximum reading range of up to 12 meters.

A Rectangular Patch Antenna for a Rfid Tag Designed for Metallic Objects with Reduced Losses

Generally UHF RFID tags do not work well near metal or water at higher frequency. We have to design an antenna to minimize this so that RFID tag can work efficiently at higher frequency. A compact micro strip Patch type RFID tag antenna design for metallic objects application is proposed in this letter. Micro-strip patch antenna has the characteristic of both antennas Patch antenna is resonating at Frequency of 900 MHz. Micro strip antennas offer a potential solution, but suffer from manufacturing complexity because a need for via or some other reference to ground .Simulation and measurement results of the proposed RFID tag antenna are also presented in this letter.

Design of compact circularly polarized radio frequency identification tag antenna for metallic object application

AbstractA passive UHF band radio frequency identification tag antenna design is presented in this article. To allow compact size and circular polarization (CP) radiation, a radiating square patch is loaded with two pairs of unequal slits, while a quarter‐wave microstrip line connected to a tag chip and terminated by a short‐circuited stub line is used to excite the radiating patch. The 10‐dB impedance bandwidth of the tag antenna is measured to be 31 MHz (896–927 MHz), whereas its 3‐dB CP bandwidth is 6 MHz (911–917 MHz). Further experiment has demonstrated that the proposed tag antenna can provide better reading distance when mounted on a metallic surface as compared with the free‐space condition. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1481–1485, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27607