Smart Antennas for Automatic Radio Frequency Identification Readers

최근 RFID (Radio Frequency Identification) 기술이 다양한 분야에서 관심을 받고 사용됨으로써 RFID 리더 제조회사들은 다양한 종류의 리더를 생산하고 있다. 현재 RFID 기술에서 RFID 태그 데이터 전송 형태는 EPCglobal에서 제공하는 표준 규약을 따르고 있지만 각 리더 별 리더 연결 및 통신 방법은 회사별로 다른 실정이다. RFID 리더를 사용하던 중 타 회사나 리더 인터페이스가 다른 RFID 리더로 변경하거나 새롭게 추가해야 하는 경우에는 사용자가 직접 RFID 미들웨어 개발단계로 돌아가 미들웨어의 내부 요소를 변경해야 하는 상황이 발생한다. 본 논문에서는 RFID 기술을 사용 시, 특히 여러 회사 또는 표준화되지 않은 인터페이스를 제공하는 RFID 리더를 사용하는 경우에 RFID 애플리케이션과 독립적으로 리더를 관리할 수 있는 리더 프레임워크를 개발하고자 한다. 본 리더 프레임워크는 RFID 애플리케이션과 RFID 리더 사이에 존재하여 RFID 리더 투명성을 제공한다. 본 리더 프레임워크는 현재 작동되고 있는 리더를 모니터링 할 수 있고, 리더의 속성을 확인할 수 있으며 RFID 태그 이벤트 정보, 시스템 로그 정보를 확인할 수 있다. 본 리더 프레임워크를 통해 수십 대의 이기종의 RFID 리더 상태를 용이하게 관리할 수 있게되며 애플리케이션 상의 코드 수정 없이 리더의 추가, 삭제가 가능하게 된다. More recently, variety RFID (Radio Frequency Identification) readers are produced by RFID equipment manufactures. Although a transmission standard instituted by EPCglobal is proposed for data transmission between the RFID readers and tags, other RFID reader protocols and the communication connection methods are be in use in other RFID companies. To replace or add the RFID readers of an RFID system, the developers should make changes to the core of the application and/or middleware. In this paper, we propose an RFID reader framework which can manage RFID readers without having to make changes the code of the application in environment with the growing number of heterogeneous RFID readers.This framework that sits on the layer between the RFID readers and the applications provides transparency to the RFID readers. Additionally, it can be used for monitoring the state and the property of all connected RFID, and for recording the RFID tag event logs and system logs. By using this framework, heterogeneous readers can be replaced and added without writing additional code in the applications. Consequently the readers can be easily managed and controlled by the RFID system administrator.

Radio Frequency IDentification (RFID) technology successfully integrates radio transmitter and receiver, small size memory space and control circuitry to remotely store and retrieve data via wireless RF transceiver. As low-cost RFID tag can be massively manufactured by semiconductor industry, new applications associated with RFID technology have emerged rapidly such as inventory tracking, book storage and management, and airport baggage handling. Generally an RFID system is composed of many RFID tags (or tagged objects), at least one RFID reader, and one backend application system with database. An RFID tag gains its operation energy from query signals that are radio waves transmitted by RFID reader. Once a tag responds the query with its stored information to RFID reader, usually a unique identity number or string, the RFID system can recognize the tag carrier and perform required business logic operation. As RFID technique is widely used in supply chain management, the corresponding RFID application systems are expected to process and manage large amount of tagged objects at a predefined period of time regularly. Therefore, for large-scaled RFID applications, tag reading throughput is very critical since it will affect the total data processing time. To measure tag reading throughput of a RFID system, two performance criteria are usually adopted: tag reading delay and reader energy consumption [5]. As RFID reader and tag always communicate over a shared wireless channel, it is very easy to have signal collisions during a normal tag identification process when multiple tags exist in reader’s interrogation area. Signal collision results in query or data retransmission and eventually increases communication overhead and time delay of tag identification. Hence, an efficient tag collision arbitration mechanism is very important and critical for RFID systems to achieve effective performance. Existing RFID tag identification schemes can be classified into aloha-based solutions [3, 10, 12-13, 16, 21, 23-24] and tree-based solutions [1, 2, 4, 6-9, 14-15, 17-20, 22]. In aloha-based schemes, a reader estimates the number of tags in its interrogation area and broadcasts the total number of timeslots to each tag. Then each RFID tag randomly selects its own timeslot to transmit its ID without knowing which timeslots have been selected by other tags. By distributing tag responses to distinct timeslots instead of getting all tag responses at the same time, aloha-based schemes effectively reduce the probability of signal collision. However, aloha-based schemes have tag starvation problem in which certain tags may not

In this paper, we focus on configuring a low cost RFID (Radio Frequency IDentification) system with less RFID readers and low density RFID tag textiles for stable and accurate self-localization for an omni-directional mobile robot. An RFID system using multiple RFID readers and high density RFID tags has already been applied to an indoor mobile robot self-localization. However, the system production cost is relatively high. To reduce the production cost of the system while maintaining the self-localization performance, we redesign two new RFID systems configured with 20 RFID readers and 5 RFID readers enlarging the size of an RFID reader antenna. Particularly, a new likelihood function of the tag detection with the redesigned large size RFID reader antenna is proposed for Monte Carlo Localization (MCL). Furthermore, we come up with a novel arrangement of RFID tags installed in a hexagon pattern. The new arrangement of ID tags enables both low cost ID tag installation and high performance of self-localization. We examine the performances of robot self-localization with less RFID readers and lower density RFID tags installed on the floor based on MCL(Monte Carlo localization). The simulation demonstrates the validity of our proposed configuration of the RFID based self-localization.

Radio frequency identification (RFID) technology can automatically and inexpensively track items as they are moved through the supply chain. This can automate the whole updating and management system, thereby making the system work with a much smaller workforce and reducing the error that can occur because of interference by human beings. One of the major advantages RFID provides is that it does not require direct physical contact with the objects and also does not require the object to be placed in its ‘Line-of-Sight’. This has given it an edge over other auto-identification systems, like bar-codes. The recent proliferation of RFID tags and readers would require dedicated and very efficient middleware solutions that manage readers and process the vast amount of captured data according to the need of various applications. RFID middleware is the software sitting in between various RFID readers and the enterprise applications. Extracting meaningful information out of huge amount of scan data is a challenging task. In this paper we like to analyze the requirements and propose a design for such an RFID middleware. This paper demonstrates how to enable the middleware to handle a large amount of RFID scan data and execute business rules in real-time. The conventional existing middleware solutions show dramatic degradation in their performance when the number of simultaneously working readers increases. Our proposed solution tries to recover from that situation also. One of the major issues for large scale deployment of RFID systems is the design of a robust and flexible middleware system to interface various applications to the RFID readers. Most of the existing RFID middleware systems are costly, bulky, non-portable and heavily dependent on the support software. Our work also provides flexibility for easy addition and removal of applications and hardware.

In this paper, the simulation of radiation pattern of the proposed RFID C-slot tag antenna on a coated metallic cylindrical surface is presented. It is found that the radiation pattern in the shadow zone (behind the product) from the proposed RFID tag is stronger than that from the electric current source case (electric tag). Thus, the proposed C-slot tag antenna is useful for the RFID application especially for the curved metallic surface product.

New mutual agreement protocol to secure mobile RFID-enabled devices

We developed hardware and software to perform exposure studies of the effects of certain radio frequency (RF) electromagnetic fields on solid and liquid pharmaceuticals and biologies. The RF fields generated by our systems are similar to those emitted by radio frequency identification (RFID) readers operating in the USA licensed high frequency (HF) and ultra high frequency (UHF) bands (13.56 and 915 MHz respectively). Our systems can expose drug samples (pharmaceuticals and biologies) to uniform electric (E) and/or magnetic (H) fields at levels that are much higher than those experienced by drugs near "worst-case" readers at a distance of 20 cm. Worst-case readers are defined as those that emit the highest allowable field strengths. Maximum field strengths near these readers were identified by measurements and computations of fields from commercial readers, and are extrapolated to the maximum allowable effective isotropic radiated power or field strength dictated by the U.S. Federal Communications Commission (FCC). The UHF system we developed included a commercially available circularly polarized antenna, a microwave generator with pulse modulation, a high power amplifier, a plastic foam enclosure, and fiber optic temperature monitoring probes placed in the drugs and the surrounding air. The HF system we developed included a specially designed Helmholtz coil pair, an HF signal generator with pulse modulation, an HF amplifier, an RF impedance matching device, and the same enclosure, and thermometry system as in the UHF system. Exposures can be performed for each drug in both its retail primary package (the smallest container produced with an RFID tag on it, e.g. bottle) and in 54 mm diameter culture dishes. The containers are suitable for exposing a wide variety of formulations of drugs (tablets, liquids, powers, capsules, creams, etc.). Exposures of drugs in culture dishes assure uniform induced electric fields and currents. In contrast, exposures in the primary containers (e.g. vials) allow studies that account for the interactions of RF fields with the packaging materials and container geometry. In our UHF system we can expose drugs to over 20 watts effective isotropic radiated power over 5 times the FCC limits. We evaluated H fields emitted by commercially available RFID readers. In our HF system we can expose drugs to at least 5 times the H field they produce at 20 cm from the reader. We can expose samples to 5 A/m in primary packaging or in special organ culture dishes with an outer concentric ring. The ring has inner and outer diameters of 32 mm and 55 mm respectively. Computer monitoring of power, drug temperature, and air temperature can be performed continuously during exposure. Surrounding air temperature is monitored at all times while in our lab (storage and exposure) and while shipped to drug laboratories for analysis.

This study is motivated by the observations on the data collected by radio frequency identification (RFID) readers in a pilot study, which was used to investigate the feasibility of implementing an RFID-based monitoring system in an outpatient eye clinic. The raw RFID data collected from RFID readers contain noise and missing reads, which prevent us from determining the tag location. In this paper, fuzzy logic-based algorithms are proposed to interpret the raw RFID data to extract accurate information. The proposed algorithms determine the location of an RFID tag by evaluating its possibility of presence and absence. To evaluate the performance of the proposed algorithms, numerical experiments are conducted using the data observed in the outpatient eye clinic. Experiments results showed that the proposed algorithms outperform existing static smoothing method in terms of minimizing both false positives and false negatives. Furthermore, the proposed algorithms are applied to a set of simulated data to show the robustness of the proposed algorithms at various levels of RFID reader reliability.

Radio frequency identification (RFID) technology is used to identify RFID-tagged objects automatically. An RFID system generally consists of three components: an RFID tag, an RFID reader, and a backend system. An RFID tag is a small device for identification, which is attached to or embedded in an object. It has an unique identifier and may optionally hold additional product information for the object. An RFID reader is a device used to interrogate RFID tags. It can be fixed or portable. It passes communication messages between an RFID tag and a backend system. A backend system stores and manages the online data which are associates with RFID tags. Since the communication between an RFID tag and an RFID reader occurs without optical line of sight, RFID tags can be read much longer and much faster than other automatic identification and data capture (AIDC) technologies such as Bar-codes and smartcards. Thanks to these advantages, RFID technology has various applications.

Radio frequency identification (RFID) and wireless sensor networks (WSNs) have been popular in the industrial field, and both have undergone dramatic development. RFID and WSNs are well known for their abilities in identity identification and data transmission, respectively, and hence widely used in applications for environmental and health monitoring. Though the integration of a sensor and an RFID tag was proposed to gather both RFID tag and sensed information, few previous research efforts explore the integration of data transmission modes in the RFID and WSN systems to enhance the performance of the applications. In this paper, we propose a hybrid RFID and WSN system (HRW) that synergistically integrates the traditional RFID system and WSN system for efficient data collection. HRW has hybrid smart nodes that combine the function of RFID tags, the reduced function of RFID readers, and wireless sensors. Therefore, nodes can read each other's sensed data in tags, and all data can be quickly transmitted to an RFID reader through the node that first reaches it. The RFID readers transmit the collected data to the back-end servers for data processing and management. We also propose methods to improve data transmission efficiency and to protect data privacy and avoid malicious data selective forwarding in data transmission. Comprehensive simulation and trace-driven experimental results show the high performance of HRW in terms of the cost of deployment, transmission delay and capability, and tag capacity requirement.

The excessive use of digital platforms with rapidly increasing users in the wireless domain enforces communication systems to provide information with high data rates, high reliability and strong transmission connection quality. Wireless systems with single antenna elements are not able to accomplish the desired needs. Therefore, multiple-input multiple-output (MIMO) antennas are getting more attention in modern high-speed communication systems and play an essential part in the current generation of wireless technology. However, along with their ability to significantly increase channel capacity, it is a challenge to achieve an optimal isolation in a compact size for fifth-generation (5G) terminals. Portable devices, automobiles, handheld gadgets, smart phones, wireless sensors, radio frequency identification and other applications use MIMO antenna systems. In this review paper, the fundamentals of MIMO antennas, the performance parameters of MIMO antennas, and different design approaches and methodologies are discussed to realize the three most commonly used MIMO antennas, i.e., ultra-wideband (UWB), dual-band and circularly polarized antennas. The recent MIMO antenna design approaches with UWB, dual band and circularly polarized characteristics are compared in terms of their isolation techniques, gain, efficiency, envelope correlation coefficient (ECC) and channel capacity loss (CCL). This paper is very helpful to design suitable MIMO antennas applicable in UWB systems, satellite communication systems, GSM, Bluetooth, WiMAX, WLAN and many more. The issues with MIMO antenna systems in the indoor environment along with possible solutions to improve their performance are discussed. The paper also focuses on the applications of MIMO characteristics for future sixth-generation (6G) technology.

This paper investigates a small size 2 × 2 wideband multiple input multiple output (MIMO) antenna covering frequency band of 2.61 to 5.52 GHz. The antenna structure consists of elliptical ring patch with multiple circumferential slots. The edge-to-edge separation between the patches are kept 3.6 mm with volumetric dimensions of 30 × 46 × 1.6 mm3. The narrow slits are etched in the tapered ground plane to obtain the wideband characteristics. The electromagnetic coupling is improved more than 16 dB by employing the neutralization technique. The measured average gain and radiation efficiency of the proposed antenna are above 2.61dBi and 83.54%, respectively across the operating band. In addition to that, the important MIMO diversity parameters are investigated. The group delay and signal analysis in different orientations are also studied to ensure the quality performance of the antenna. The proposed MIMO antenna is simulated using CST microwave studio and further validated with the measurements. In addition to that, the parallel and orthogonal configuration of 4 × 4 MIMO antennas are analyzed by extending the proposed 2 × 2 MIMO design. The 4-port MIMO antennas exhibit the operating frequency bands varying from 2.80 to 5.58 GHz and 3.4 to 5.52 GHz, respectively for parallel and orthogonal MIMO configurations. The diversity parameters of 4-port MIMO antennas are calculated and compared with the measured results to verify its practical applications. Finaly, the SAR analysis of the antenna is presented at 3.08 and 5.20 GHz for 1/10 g tissues and are found 0.111/0.106 and 0.079/0.063 W K−1g−1, respectively. The proposed MIMO antenna designs are suitable for modern high-speed communication for 5G and sub-6 GHz frequency bands.

Radio Frequency Identification (RFID) is a modern wireless data transmission and reception technique for applications including automatic identification, asset tracking and security surveillance. As barcodes and other means of identification and asset tracking are inadequate for recent demands, RFID technology has attracted interest for applications such as logistics, supply chain management, asset tracking, and security access control. However, the cost of RFID limits their potential for the replacement of trillions of barcodes each year. The only possible solution is a fully printable chipless RFID tag. A novel RFID system comprised of a chipless RFID tag and an associated reader is reported in the thesis. The chipless tag is a fully-passive microwave circuit and uses spectral signatures for data encoding. The tag consists of a multi-resonator coupled to transmitting and receiving antennas. To accommodate multiple bits, the tag operates over the ultra wideband (UWB) frequency spectrum. UWB antennas are used to receive the interrogation signal sent from the reader and transmit the signal back to the reader after performing modulation of the frequency spectra with the multi-resonator. Modulation is performed in both amplitude and phase of the spectrum. A chipless tag up to 35 bits which operate over 3-7 GHz band has been designed. After the successful design of the chipless tag, three prototype readers have been developed. The Gen1 reader was designed to validate the chipless RFID concept using 6-bit chipless tag reading based on amplitude-only detection in S-band; the Gen2 reader is an upgraded version of Gen1 with both amplitude and phase detection capability; and the third generation reader is a UWB reader capable of reading up to 35-bits in the UWB band. The integrated reader is a complete system with analog RF and digital control sections loaded with graphical user interface (GUI) and software protocol. Both the hardware and software design of the RFID reader and field trials of the designed chipless RFID system have been validated in the real world environment. An investigation into antenna systems in order to enhance reading range up to 70 cm has also been performed. The unique features of the developed chipless RFID system are: (i) a low cost, fully printable tag and (ii) secure, remote and non-line-of-sight operability. The importance of this concept lies in the fact that chipless RFID tags become comparable to barcodes in terms of the substrate material used and the cost of fabrication. The main application of this chipless RFID system is in short-range tagging of extremely low cost items such as the Australian polymer banknote.

Oilfield tubulars (typically metallic pipes) and other types of oilfield equipment are typically stored in outdoor areas and may be scattered around the field. Managing these types of inventory is challenging and costly, as it requires significant labor resources. Therefore, inventory inaccuracy is common, and data-driven decisions may not be possible in a timely manner. We propose the use of radio frequency identification (RFID) for tracking oilfield tubulars and similar, outdoor-stored, equipment. Our proposed application utilizes passive ultra-high frequency (UHF) RFID technology that enables capturing unique serial identification numbers that are attached to inventory items from a distance of several meters. Passive UHF RFID tags require no batteries to operate. Typical tag cost is low. Each tag is placed on an inventory item and corresponds to a database entry containing specific information about this item. The tag communicates its serial number using power provided by an RFID reader radio transmission. The RFID reader is securely mounted to the underside of a UAV flown over the field. Captured RFID tags are either stored locally and retrieved once the UAV lands, or are wirelessly transmitted to a constantly updating inventory database. In addition to tag ID, the captured data typically includes time and date stamp, as well as location data. This research project included the design and manufacturing of an enclosure to house a RFID reader system which includes a host computer, embedded reader, antenna, power source, and necessary components for user interface. Specialized mounts were designed and manufactured to attach the enclosure and antenna to the UAV. The project incorporated the development of "middleware", specialized software installed on the host computer to communicate with the reader. The reader handles low-level communication with the antenna. To reduce network traffic, event management and data filtering are efficiently performed. The results of several UAV flights in experimental areas are presented and discussed. Various brands of passive RFID tags for oilfield applications were tested. Particular attention was given to population density of the items, stacking configuration, vertical altitude distance between reader and tags, and time to collect inventory data for a given area of surveillance. As RFID applications are increasing in the oil, gas, solar, and other sectors of the energy production industries, UAVs can effectively be used to get important operational and inventory data. UAV use is particularly appealing in inaccessible and remote locations.

Inteli-Straw (I-S) devices equipped with radiofrequency identification (RFID) technology were developed for gamete and embryo packaging, storage, and information retrieval to benefit the assisted reproduction industry. The aim of this study was to develop and test software for use with I-S technology. Two types of I-S were used, those with 125 and 134 kHz RFID chips, in conjunction with corresponding wireless RFID readers. Two different RFID chip designs were tested: (1) Mini: 0.25-mL straw, RFID tag dimensions = 1.25 × 7 mm and 1.4 × 8 mm; Standard: 0.5-mL straw, RFID tag dimensions = 2 × 12 mm; and (2) µ-chip (Hitachi Ltd., Tokyo, Japan) of 0.4 mm square and 0.06 mm thick. Inteli-Straw RFID chips can be written or have codes that can be associated with information in a database. The present RFID chips were used with the idChamp DX1 Veterinary & Livestock RFID Reader that uses Bluetooth to connect to an iOS platform for cloud computing. The iScanBrowser (Serialio, TX, USA) LED, an app for an iOS platform for use with a wireless RFID reader, was utilised, as well as a proprietary gamete and embryo database software. The present system allows for quickly accessing the RFID codes from the various I-S gamete and embryo packaging (before or after I-S filling) and entering the data into a computer or cloud-based database that can track their status, movement, metadata, and so on. The ability to acquire I-S information with wireless entry into the cloud-based database was achieved. When the RFID wireless reader detects an I-S, the RFID code is displayed almost immediately (~1 s) in a cell in the software system. The I-S (n = 194) were scanned for automatic database entry. For the wireless-enabled proof of concept, 17 scans of I-S [i.e. RFID chip design 1 (n = 15) and design 2 (n = 2)] were made with wireless scanner detection (< 2.5 cm from RFID reader to I-S) and online database entry with a 100% success rate. By using this I-S method, the present invention provides a wireless, cloud-based system for local or remote access, potentially benefiting both laboratory and field logistics. For AI and embryo transfer, the user can scan an I-S and the information is automatically detected; wireless cloud computing and RFID data crosschecking can occur; and the information can be uploaded to a database for later retrieval or analysis. Further, one can use an iphone or ipad to enter other information such as cow number into the cloud-based database during AI or embryo transfer. The present system can allow for near real-time viewing of the data, locally and remotely, or cross-checking of materials and associated information to reduce errors and improve assisted reproductive technology efficiency.