Radio Frequency Identification Antenna Research Articles

Construction material mountable UHF RFID tag antenna

ABSTRACTThis article presents a tag antenna for radio frequency identification (RFID)‐based wireless structural health monitoring systems. An ultra‐high frequency (UHF) microstrip patch tag antenna is designed with a new generation RFID tag chip for the Australian UHF RFID frequency band. Simulation studies with optimized slits demonstrate the ability of the antenna to tolerate the influence of construction materials such as concrete and metal on its resonant frequency, maximum gain, and read range. Noncontact measurement of the resonant frequency and experimental verification of the maximum gain of the fabricated tag antenna show good agreement with simulated performance. Read range measurements are conducted to verify the performance of the tag antenna on metal structures. It is also shown that the proposed tag antenna can be easily modified to operate in other UHF RFID frequency bands. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2231–2237, 2016

Self-Powered Wireless Affinity-Based Biosensor Based on Integration of Paper-Based Microfluidics and Self-Assembled RFID Antennas.

This paper presents a wireless, self-powered, affinity-based biosensor based on the integration of paper-based microfluidics with our previously reported method for self-assembling radio-frequency (RF) antennas. At the core of the proposed approach is a silver-enhancement technique that grows portions of a RF antenna in regions where target antigens hybridize with target specific affinity probes. The hybridization regions are defined by a network of nitrocellulose based microfluidic channels which implement a self-powered approach to sample the reagent and control its flow and mixing. The integration substrate for the biosensor has been constructed using polyethylene and the patterning of the antenna on the substrate has been achieved using a low-cost ink-jet printing technique. The substrate has been integrated with passive radio-frequency identification (RFID) tags to demonstrate that the resulting sensor-tag can be used for continuous monitoring in a food supply-chain where direct measurement of analytes is typically considered to be impractical. We validate the proof-of-concept operation of the proposed sensor-tag using IgG as a model analyte and using a 915 MHz Ultra-high-frequency (UHF) RFID tagging technology.

Passive RFID for Object and Use Detection during Trauma Resuscitation

We evaluated passive radio-frequency identification (RFID) technology for detecting the use of objects and related activities during trauma resuscitation. Our system consists of RFID tags and antennas, optimally placed for object detection, as well as algorithms for processing RFID data to infer object use. To evaluate our approach, we tagged 81 objects in the resuscitation room and recorded RFID signal strength during 32 simulated resuscitations performed by trauma teams. We then analyzed RFID data to identify cues for recognizing resuscitation activities. Using these cues, we extracted descriptive features and applied machine-learning techniques to monitor interactions with objects. Our results show that an instance of a used object can be detected with accuracy rates greater than 90 percent in a crowded and fast-paced medical setting using off-the-shelf RFID equipment, and the time and duration of use can be identified with up to 83 percent accuracy. We conclude with insights into the limitations of passive RFID and areas in which RFID needs to be complemented with other sensing technologies.

Sectored annular ring microstrip antenna with DGS for circular polarization

ABSTRACTA novel and simple design of circularly polarized sectored annular ring microstrip antenna with coplanar and concentric circular microstrip antenna is presented. The proposed antenna has single microstrip line feed with defected ground structure. Simulation analysis has been carried out using Ansoft High Frequency Structure Simulator (HFSSTM) software and measurement is carried out using the AgilentTM Vector Network Analyser (N5230A:PNA‐L). Parametric analysis of return loss and axial ratio versus frequency for different physical parameter of antenna has been studied. Experimental results of the proposed antenna show the 34.61% impedance bandwidth and 8.08% axial ratio bandwidth at 2.6 GHz center frequency with 6.96 dB peak gain. Simulated results are in good agreement with measured results. Due to low profile and simple geometry, it can be applicable for S‐band application effectively as wireless LAN, Wi‐Fi, Bluetooth, Zig‐Bee, and radio frequency identification antennas. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:569–573, 2016

CPW AND MICROSTRIP LINE-FED COMPACT FRACTAL ANTENNA FOR UWB-RFID APPLICATIONS

In this study, we present an implementation of Ultra Wide Band (UWB) Koch Snowflake antenna for Radio Frequency Identification (RFID) applications. The compact antenna, based on the Koch Snowflake shape, is fed by coplanar waveguide (CPW) and by microstrip line with an overall size of 31 × 27 × 1. 6m m 3 . The simulation analysis is performed by CST Microwave Studio and compared with HFSS software. The antenna design exhibits a very wide operating bandwidth of 13 GHz (3.4- 16.4 GHz) and 11 GHz (3.5-14.577 GHz) with return loss better than 10 dB for microstrip line antenna and CPW antenna respectively. A prototype of CPW and microstrip antenna was fabricated on an FR4 substrate and measured. Simulated and measured results are in close agreement. The small size of the antenna and the obtained results show that the proposed antenna is an excellent candidate for UWB-RFID localization system applications.

Analysis of RFID Based Positioning Technique Using Received Signal Strength and Directional Antenna

Automatic robot navigation is being utilized in many industries for the purpose of high speed work delivery. Color follower, fix path follower robots are current solution to this activities but dynamic path configuration is not possible in these robots. Hence new system proposes effective and fully dynamic path follower robots using RFID and directional antenna. Radio Frequency Identification (RFID) system permits automatic identification of objects with RFID tags using radio waves which have been widely used in mobile robot navigation, localization and mapping both in indoor and outdoor environment. This article presents a navigation strategy for autonomous mobile robot using passive RFID system. Proposed robot system is provided with RFID tag functionality which will load tag number and direction instruction. At some turning point, user will put RF tag, this tag will be read by RF reader which is placed on robot. As per direction instruction robot will change the direction and reach to the destination. Also as per the movement, robot will send its GPS location to PC (Personal Computer) which will be displayed on PC. Hence main goal is to provide more reliable and low energy consumption based indoor positioning system which will be achieved using directional antenna.

Embedded UHF RFID Tag for Durability Monitoring in Concrete

This paper describes the design of a battery-assisted Ultra-High Frequency (UHF) Radio-Fre- quency IDentification (RFID) tag suitable for embedding in concrete materials and its measurement in a mortar slab. The device is built to communicate wirelessly not only the ID number of the RFID chip but also the digitalized output of a strain gauge sensor. Design optimizations of the RFID antenna is based on published permittivity and conductivity values of concrete. Experimental read ranges are measured from 800 to 1000 MHz with the help of commercial test equipment. Reading is possible up to 50 cm from the surface of a mortar block for a tag embedded 5 cm below the surface. This result is the first published one for RFID tags embedded in concrete or mortar.

Measuring the drinking behaviour of individual pigs housed in group using radio frequency identification (RFID)

Changes in the drinking behaviour of pigs may indicate health, welfare or productivity problems. Automated monitoring and analysis of drinking behaviour could allow problems to be detected, thus improving farm productivity. A high frequency radio frequency identification (HF RFID) system was designed to register the drinking behaviour of individual pigs. HF RFID antennas were placed around four nipple drinkers and connected to a reader via a multiplexer. A total of 55 growing-finishing pigs were fitted with radio frequency identification (RFID) ear tags, one in each ear. RFID-based drinking visits were created from the RFID registrations using a bout criterion and a minimum and maximum duration criterion. The HF RFID system was successfully validated by comparing RFID-based visits with visual observations and flow meter measurements based on visit overlap. Sensitivity was at least 92%, specificity 93%, precision 90% and accuracy 93%. RFID-based drinking duration had a high correlation with observed drinking duration (R2=0.88) and water usage (R2=0.71). The number of registrations after applying the visit criteria had an even higher correlation with the same two variables (R2=0.90 and 0.75, respectively). There was also a correlation between number of RFID visits and number of observed visits (R2=0.84). The system provides good quality information about the drinking behaviour of individual pigs. As health or other problems affect the pigs’ drinking behaviour, analysis of the RFID data could allow problems to be detected and signalled to the farmer. This information can help to improve the productivity and economics of the farm as well as the health and welfare of the pigs.

Radio Frequency Identification Upon Near Field Communication and Far Field Communication For Next Generation Wireless Network Infrastructures

The electromagnetic field that outlines the RFID antenna can be divided up into two portions – Near-field and Far-field. Near Field Communication (NFC) and Far-Field communication (FFC) both are the most emerging wireless short-range communication technologies, both are based on existing standards of the Radio Frequency Identification (RFID) network framework. In collaboration with NFC-efficient next generation smartphones it authorizes automatic application frameworks for contact less connections, in different exceptional utilities for future generation smartphone payment and over-the air ticketing. The principle aim of current study is to explain basic characteristics and benefits of the wireless short- range technologies like (RFID, NFC, and FFC) and analogy between them to classify modes of operation and to present various illustrations. NFC mechanism, applications and FFC with possible future or Next Generation scenarios will be analyzed. Finally, this study provides the fundamental security concerns; challenges and present conflicts will be investigated in order to achieve the efficiency in Next Generation Network Infrastructures.

A Novel RFID Antenna with HIS Structure for Ka Band

In this paper the radio-frequency identification (RFID) concept is expanded to millimeter-wave frequencies and millimeter-wave identification. In the first part of this paper, we will focus on the design of a notched patch antenna operating at 30 GHz (Ka Band) using CST- Microwave-studio software. In the second part, we will analyze the behaviors of this patch antenna surrounded by one of the well-known High Impedance Surface (HIS): HIS of Sievenpiper. Through computer simulations, we will demonstrate that adding this surface to the design of the notched patch antenna reduces significantly the wave surface propagation. As a result, we will improve the antenna performances such as gain, directivity and bandwidth. The experimental measurements taken using the proposed antenna are in good agreement with the computational results.

Circularly polarized square slot microstrip antenna for RFID applications

In this paper, a novel circularly polarized square slot microstrip antenna is proposed for radio frequency identification (RFID) applications. The circular polarization is achieved by incorporating an arc-shaped strip in the square slot antenna. This antenna is fed by deformed bent feeding line to achieve a broad bandwidth (BW). The key parameters of the antenna are used for parametric study to understand the influence on the antenna performance. To validate simulation results of the design, a prototype is fabricated on the commercially available FR4 material. Measured results show a good agreement with the simulated results. It is found that the antenna shows an impedance BW of 170 MHz (844–1014 MHz) and axial-ratio BW of 170 MHz (834–1004 MHz), which shows that the proposed antenna is a good candidate to be used as a RFID antenna.

Quantifying detection performance of a passive low-frequency RFID system in an environmental preference chamber for laying hens

Radio Frequency Identification (RFID) systems are widely used in production livestock systems for identification, traceability assurance, and animal registration. An RFID system was implemented and evaluated for use in a four-compartment, two-tier, environmental preference chamber (EPC) to detect hens transiting between compartments. Eight RFID antennae were located near the passages between compartments and each hen wore an RFID tag on one of its legs. The RFID system’s performance was assessed by determining detection ranges in a controlled test and by comparing the number of entries into and duration in each compartment as detected by the RFID system to manual assessment of recorded video. The RFID system detection range was revealed to cover a radius of approximately 29cm from the antenna, excluding a portion of the compartment furthest from the antenna. During a choice-test study, successful detection rates based on duration of stay in compartments were 91.0±2.6% (mean±SD) for trials with groups of birds, and 85.8±8.0% for trials with individual birds. Based on number of entries into compartments, successful detection rates were 62.6±11.2% for trials with groups of four birds, and 51.3±18.4% for trials with individual birds. Sources of entry misdetection included: (i) RFID tag being out of the detection range during sampling; (ii) conflicts caused by multiple RFID tags within the same detection zone; and (iii) visits of duration less than the RFID antenna scan interval. The delay between hen entry and RFID system detection averaged 42.3±35.7s and 6.4±5.2s in trials with individuals and with groups, respectively. Detection times were within the antenna scanning interval of 15s (a hen entered a compartment and was immediately detected by the next antenna scan) in 60.3% of the events with individuals and 98.1% of the events with groups. Despite the difference between detected and actual entries (P=0.008 [groups]; P=0.05 [individuals]), no significant differences were found between total duration of compartment occupancy over a 24h test period or average compartment visit duration, as calculated from RFID data and video observations. The RFID system was suitable for characterizing the amount of time birds spent in each EPC compartment, but not reliable for determining number of entries into a compartment.

Inductance Investigation of Screen-Printed Radio Frequency Identification Antennas

Printed antennas fabricated using conductive ink printed on flexible substrate is low-cost and environmental friendly. The inductance and the quality factor are two important parameters for designing RFID antenna and were studied for the printed RFID antennas. The results show that the inductance is not only determined by the size of the designed RFID antenna but also related to the resistance of the printed antenna coils. The inductance increases with the increasing testing frequency, while the Q value decreases with the increasing testing frequency. The soft magnetic ink prepared with γ-Fe2O3 was used to enhance the inductance of the printed antennas with printing technology. The inductance of the printed antenna with the magnetic core layer is increased by 5.7% at 13.56 MHz.

A Compact Circularly Polarized Crossed-Dipole Antenna for an RFID Tag

A compact circularly polarized (CP) crossed-dipole antenna for radio frequency identification in the ultra-high frequency is proposed. The antenna consists of two orthogonal dipoles with an arm composed of a meander line and triangular-shaped ending for achieving a compact size. A modified T-match with a meander line is used for impedance matching between the antenna and the tag chip. In this design, CP excitation is achieved by incorporating two semi-circular curves inserted between the orthogonally arranged dipole arms. The final design, with the dimensions of 35.6 ×35.6 ×0.508 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , yields a -10-dB impedance bandwidth of 37 MHz (892-929 MHz) and a 3-dB axial-ratio bandwidth of 11.4 MHz (905.2-916.6 MHz). The measured results show that the proposed tag antenna can provide a maximum reading distance of approximately 7.6 m with an effective isotropic radiated power of 3.28 W over the CP operational bandwidth.

Fundamental Characteristics of Electro-Textiles in Wearable UHF RFID Patch Antennas for Body-Centric Sensing Systems

Electro-textiles feature excellent radio frequency (RF) performance. They have an enormous potential to be widely accepted in body-centric sensing systems as wearable antenna materials. However, the RF community lacks comprehensive knowledge of electro-textile fundamental characteristics. This paper provides critical electro-textile design parameters for wearable radio frequency identification (RFID) ultra-high-frequency (UHF) patch antennas. For the first time, modeling parameters for embroidered antenna ground plane and patch structures are established and verified. The results highlight a new unprecedented fundamental characteristic of embroidered antennas: all embroidered structures, modeled as uniform and infinitely thin textile layer, have an existing imaginary part in their sheet impedance modeling parameter. It accounts for the antenna input inductance contributed from the electro-textile. Ideally, such as for highly conductive fabrics and pure conductors, the imaginary part is negligible. Utilizing the proposed design guidelines, a fully wearable and flexible embroidered RFID patch antenna is for the first time realized. Its performance may be considered as a benchmark for future designs. The design parameters and findings form an important milestone in the development towards wearable intelligence and foster industrial developments of garment-integrated RFID antennas.

Automated tracking of wild hummingbird mass and energetics over multiple time scales using radio frequency identification (RFID) technology

We examined the feasibility of automating the collection of hummingbird mass data facilitated by low‐cost, low‐power radio frequency identification (RFID) technology. In a field study in southern Ontario, wild hummingbirds were captured, subcutaneously implanted with passive integrated transponder (PIT) tags, and released over a three‐year period. Tagged hummingbirds were detected at specially designed feeder stations outfitted with low‐cost, low‐power RFID readers coupled with a perch secured to a digital balance. When tagged birds visited the feeder, transponder detection initiated the recording of the perched hummingbird's mass at regular intervals continuing as long as the bird remained. This permitted a nearly continuous record of mass during each visit. Mass data collected from tagged hummingbirds showed consistent trends at multiple temporal scales: the individual feeder visit, single days, and even whole seasons. These results further confirm that RFID technology is safe for use in the smallest birds. The effective detection range is a function of RFID reader power, antenna, and tag size. Yet, we find that careful arrangement of feeders and detectors allows for reliable detection even when detection range is low. When coupled with additional technologies, such as a precision electronic balance, this approach can yield robust serial measures of physiological parameters such as mass, an indicator of energy balance over time.

Towards practical application of paper based printed circuits: capillarity effectively enhances conductivity of the thermoplastic electrically conductive adhesives.

Direct printing nanoparticle-based conductive inks onto paper substrates has encountered difficulties e.g. the nanoparticles are prone to penetrate into the pores of the paper and become partially segmented, and the necessary low-temperature-sintering process is harmful to the dimension-stability of paper. Here we prototyped the paper-based circuit substrate in combination with printed thermoplastic electrically conductive adhesives (ECA), which takes the advantage of the capillarity of paper and thus both the conductivity and mechanical robustness of the printed circuitsweredrastically improved without sintering process. For instance, the electrical resistivity of the ECA specimen on a pulp paper (6 × 10−5Ω·cm, with 50 wt% loading of Ag) was only 14% of that on PET film than that on PET film. This improvement has been found directly related to the sizing degree of paper, in agreement with the effective medium approximation simulation results in this work. The thermoplastic nature also enables excellent mechanical strength of the printed ECA to resist repeated folding. Considering the generality of the process and the wide acceptance of ECA technique in the modern electronic packages, this method may find vast applications in e.g. circuit boards, capacitive touch pads, and radio frequency identification antennas, which have been prototyped in the manuscript.

Synthesis of air stable silver nanoparticles and their application as conductive ink on paper based flexible electronics

Air stable silver nanoparticles (NPs) at a high concentration (up to 0·2M) were synthesised by the reduction in Ag+ ions with glucose in cetyltrimethylammonium bromide (CTAB) solutions, for preparing nano-Ag ink applicable for direct writing on photo paper using a gel ink pen. The reaction was performed at room temperature, and the input of extra inert gas was not necessary. The UV/vis spectrum exhibited an absorption band at 413 nm, revealing the formation of Ag NPs. By the analysis of X-ray diffraction (XRD), the resultant particles were confirmed to be pure Ag with a face centred cubic structure. From the (high resolution) TEM analysis, it was found that the mean diameter of Ag NPs was 16·5 nm, and the morphology of the particles exhibited highly crystalline nature. In addition, the excess of CTAB was effective in reducing the aggregation and size of the Ag NPs and in improving their air stability. The reduced size and enhanced air stability of the Ag NPs resulted in an improved particle density upon sintering, which was mainly responsible for the increased conductivity of the Ag patterns. The resistivity of Ag patterns sintered at 160°C for 2 h was 6·8±0·8 μΩ cm, 4·2 times the bulk resistivity. A sample paper based electrode and circuits were successfully made, and all of them exhibited excellent flexibility and good conductivity, which can be used as part of some flexible electronic devices, such as triboelectronic generator, solar cells and radio frequency identification antenna, etc.

A gravure printed antenna on shape-stable transparent nanopaper.

This work presents a solution-processed gravure printed antenna on robust transparent nanopaper for potential Radio Frequency Identification (RFID) application. The nanopaper, having excellent dimensional stability in water, was obtained by glutaraldehyde treatment with hydrochloric (HCl) acid as a catalyst. For the first time, a device consisting of RF components for RFIDs was printed on stable nanopaper via a well-developed scalable method: gravure printing. Insertion losses of -37.9 dB and -38.85 dB for the 100 lpi and 120 lpi antennas respectively were demonstrated at the maximum gain of 683.75 MHz. The RF-based responses from the printed antenna demonstrated the feasibility of using printing technology, such as gravure printing, to fabricate flexible RFID antennas for various electronic device applications. This study paves the way for the development of low cost, disposable devices comprised of biodegradable and earth abundant materials to promote greener electronics.

Smart RFID Antenna System for Indoor Tracking and Behavior Analysis of Small Animals in Colony Cages

Radio frequency identification (RFID) technology is more and more adopted in a wide range of applicative scenarios. Nevertheless, in many applications, commercial and general-purpose solutions can be unsuitable as in the case of the tracking of small-size living animals for the behavior analysis. In such a case, the whole RFID hardware, as well as the control software, should be opportunely tailored for the particular application. In this paper, a novel RFID-based approach enabling an effective localization and tracking of small-sized laboratory animals is proposed. It is mainly based on a near-field (NF) RFID multiantenna system working in the UHF bandwidth, to be placed below the animal's cage, and able to rigorously identify the NF RFID tags implanted in laboratory animals. Once the requirements of the reader antenna have been individuated, an antenna system composed of a matrix of specifically designed segmented loops has been prototyped. Moreover, to improve the effectiveness of the whole tracking system, a properly algorithm based on the measured received signal strength indication has been developed and integrated. It aims at removing potential minor ambiguities of the data captured by the multiantenna system. The whole animal tracking system has been then largely tested on phantom mice to verify its ability to precisely localize each subject and to reconstruct its path. Additionally, a first test performed on living mice has been presented. The achieved and discussed results demonstrate the effectiveness of the proposed approach.