Development and simulation of PIE encoder architecture for UHF RFID reader based on FPGA

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.

This paper presents the design of ultra-high frequency (UHF) radio frequency identification (RFID) reader antenna using low dielectric constant of microwave substrate. An RFID reader antenna emits electromagnetic signals to the microchip in the tag, and the microchip will be energized by modulating the wave and returns to the reader antenna. The process of wave emitting is known as backscattering due to the presence of tag been detected by the reader. High-dielectric constant substrate, for example flame-retardant-4 (FR4) which is commonly used for microstrip patch antenna, is high in dielectric constant and dielectric loss. Thus, this will lead to low gain and directivity properties of the antenna. To overcome this matter, low-dielectric constant substrate which is Taconic TLY-5 was proposed to be utilized for microstrip patch antenna design. The TLY-5 microstrip substrate thickness used is 1.6 mm, dielectric constant of 2.2, and loss tangent of 0.019. A high-conductivity metal which is typically a conductive copper is been used for the two layers of dielectric substrate, the top radiating patch layer and bottom ground layer where the copper thickness is 0.035 mm. Microstrip feed line is used for this UHF RFID reader antenna. The width of the feed line was tuned to obtain impedance matching of 50 Ω. The proposed antenna which is fork-shaped patch antenna was simulated using Computer Simulation Technology (CST) and Microwave Studio software at resonant frequency of 910 MHz with the outcome results of 7.985 dB gain and −11.11 dB return loss. Nevertheless, the typical value obtained for VSWR is less than 2.

Passive UHF (ultra high frequency) RFID (radio frequency identification) is a promising technology for products tracking in logistics or routing packages in supply chain. However, passive UHF RFID tag suffers a lot when it is placed on conductive plane or water surface. Many designs like microstrip antenna and ferrite antenna have been used to solve this metal-water problem. But their use is limited by narrow bandwidth and low antenna gain. The electromagnetic band gap (EBG) material which exhibits a unique forbidden band gap at certain frequency offers a potential solution to solve the problem of backside objects effects. Previous research paper indicated that the dipole RFID antenna above three-layer mushroom like EBG material exhibited a good antenna gain and long read range. However, the complicated structure and high material cost greatly limit the application of tag. In this paper, we developed a new type of EBG material which uses ferrite film to reduce size and lower forbidden frequency. A commercial ferrite film which has a high permeability is applied to form two-layer mushroom like EBG material for UHF RFID. This two-layer mushroom like EBG material is a two-layer structure with a ground plane. The design of EBG material for UHF RFID which operates at 915 MHz was discussed in this paper. An EBG tag on metal with a gain of 7 dBi was achieved in simulation. The simulation results showed that the RFID tag still could be read on EBG substrate with a good gain (~7 dBi).

The design of an ultrahigh-frequency (UHF) radio-frequency identification (RFID) reader antenna covering an electrically large near-field area is challenging for near-field UHF RFID applications. In such a design, magnetic field distribution on a large coverage area is required to be as uniform as possible. For some specific UHF near-field RFID applications, given radiation pattern characteristics are expected. A fragment-type wire structure is quite suitable for these demands because uniform magnetic field distribution and given patterns could be generated through optimizing the fragmented wires in a designated electrically large area to obtain corresponding current distribution. In this article, the concept of a fragment-type structure as well as some design guidelines are reviewed and summarized. Then, two omnidirectional fragment-type wire antennas with different cell size and two directional fragment-type wire antennas are designed. Both simulation and experiment results show that there is no reading null within an electrically large near-field zone having a perimeter of four operating wavelengths at 915 MHz (i.e., 320 mm x 320 mm). The omnidirectional designs are promising in the applications of UHF near-field RFID tag detection in self-confined volumes, and the directional designs are potential in the systems of UHF near-field/far-field RFID.

This paper presents a 2-D localization system based on phase-of-arrival evaluation of passive ultrahigh frequency (UHF) radio frequency identification (RFID) transponders. To handle the ambiguity caused by phase evaluation, several tags are arranged to form a uniform linear array. A multiple input multiple output system, where sequentially each frontend is configured to work as transmitter, while the remaining frontends serve as receivers, is used to enable position estimation. For proof of concept, a local position measurement system demonstrator was built comprising conventional passive EPCglobal Class-1 Gen-2 UHF RFID tags, one commercial off-the-shelf RFID reader, several transceiver frontends, baseband hardware, and signal processing. Measurements were carried out in an indoor office environment, where the $3.5~{\rm m} \times 2.5$ m measurement zone was surrounded by drywalls and concrete floor and ceiling, and the experimental results showed robust and accurate localization with a root-mean-square deviation of 0.011 m and a maximum error of 0.032 m. These experimental results were confirmed by simulations, which were performed to determine the limits of the system accuracy.

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.

This paper describes the development of four different ultra-high frequency (UHF) radio frequency identification (RFID) tag antenna using polycarbonate material or transparent paper as the substrate and aluminum tape as the radiating element. The main advantage of the method is that the materials are easy to obtain where it can be found in any hardware stores or in any general online shop. Plus, the antennas are designed in such a way that a meander line is traced along the shape of a bowtie antenna so that the antenna would operate at UHF band. The results of all four of the tag antenna designs are discussed and compared using graph obtained from Computer Simulation Technology (CST) simulation results and measurement results obtained from a portable Vector Network Analyzer (VNA) for the reflection coefficient, S 11 , and measurement results taken from VNA in chamber room for the radiation pattern. Finally, the results show that the measured results are in agreement with the simulated result and that the UHF RFID tag antennas are able to operate at UHF RFID band.

Passive UHF (Ultra High Frequency) RFID (Radio Frequency Identification) is a promising technology for products tracking in logistics or routing packages in supply chain. Usually, the UHF RFID antenna is made by etched copper, or aluminum. These etching process introduce chemical wastes during the etching process. Recently, printing silver paste becomes popular due to its environmental friendly manufacturing process. However, there are two drawbacks on printed silver paste RFID antenna. One is low conductivity compared to metal and the other is the high material cost. In this paper, we exam the effects of printing thickness on the performance of UHF RFID tags and summarize the optimized thickness for different read range requirements. A commercial conductive silver paste is printed on PET film as RFID tag antennas. Both finite element simulations and experiments are conducted to evaluate the effects of printed thickness. The simulation results presents that the 10 um thick RFID antenna exhibits relatively good radiation efficiency. The results indicate that 10 um thick RFID tag antenna presents the minimum turn-on power of 18 dBm to 22 dBm which is enough for most applications. The simulation and measurement results present that thinner printed silver paste RFID tag antenna is a potential solution for low cost UHF RFID tags. The cost of these tags could be lower than current etched Al/Cu RFID tags because of material saving.

ABSTRACTIn this research, two low profile metal mountable patch antenna designs for passive ultra-high frequency (UHF) radio frequency identification (RFID) tag are proposed. The complex impedance matching between the antenna and the referenced microchip, Alien-Higgs 3 whose impedance , is realized through an inductively coupled loop feed structure where it provides the needed reactance for the tag antenna. To enhance the bandwidth of the antenna, multiple co-planar radiating patches are employed to excite several resonant modes for worldwide use. The wide impedance bandwidth also compensates for fabrication inaccuracy which could shift the operating frequency of the final antenna design. The final dimensions of the antennas are 87 × 45 × 1.6 mm3 and 130 × 63 × 1.6 mm3. The measured impedance bandwidths of the proposed antennas when mounted on a metal plate are 155 MHz (RL ≥ 3 dB), which is from 830 to 985 MHz, and 117 MHz (RL ≥ 6 dB), which is from 850 to 967 MHz, respectively. The maximum simulated gains are −7 and −11 dB at the operating frequency of 915 MHz. Based on the measurement results, it is expected that the proposed antenna would be able to provide a reasonable read range of at least 2 m throughout the entire UHF RFID band when being attached on metal objects.

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 paper presents a wideband and high gain circularly polarized ultra-high-frequency (UHF) radio frequency identification (RFID) reader antenna. Such antenna is composed of one main radiation patch and one parasitic radiation patch with air as the dielectric layer. And two feeding lines connect to the main radiation patch with 90 deg phase difference. Numerical optimizations and experimental demonstrations are performed to investigate the performances of the proposed antenna and good agreements are achieved. This antenna can cover the whole UHF RFID frequency band (840–960 MHz) with gain of 9.7 dBi, which is suitable for universal UHF RFID applications.

Ultra High Frequency (UHF) Radio Frequency Identification (RFID) is an automatic identification technology which has already explored different ventures to replace barcode systems. Near-field (NF) identification is preferred in inventory containing liquids and metals, as well as point-of-sale applications where the challenge is to have an antenna that can scale to large sizes and has no blind spots on its surface. This paper presents a scalable NF antenna design that utilizes non-conventional but commercially available materials that makes the antenna inexpensive. The antenna architecture comprises of a rectangular spiral microstrip line with intentional impedance mismatches and a finite ground plane made from conductive tapes and sheets sandwiched by a non-conventional substrate material. Traditional patch and loop NF antennas suffer from size limitation, surface dead spots and have far-field (FF) component that introduces stray tag reads. The proposed antenna design has no surface blind spots, easily scalable and has potential for building an inexpensive tracking shelve with confined read zones that can detect both NF and FF tags. The light weight, chemical resistant, non-toxic, and self-extinguishing properties of the antenna can significantly expand the range of applications and deployment environments of UHF RFID.

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.

A miniaturized circularly polarized (CP) antenna for ultra-high frequency (UHF) radio-frequency identification (RFID) reader is designed in the present paper. For the aim of miniaturizing antenna, the square radiating patch is opened by four T-shape slots. This can extend the route of surface current, as a result the operating frequency drops and the size reduces. In additional two diagonal corners of the radiation patch are truncated by a square to achieve CP operation. The designed antenna is calculated and optimized by HFSS. The optimized antenna exhibits satisfied performances, and is therefore suitable for UHF RFID reader applications. The designed antenna shows the advantages of small size, simple structure, and low cost.

In a pioneering effort, this research presents a distinctive transformation of the Government College University Faisalabad (GCUF) logo into an RFID tag antenna using characteristic mode analysis (CMA), which resonates at the entire ultra-high frequency (UHF) radio frequency identification (RFID) band for IoT applications. The logo of GCUF is simulated in a computer simulation technology (CST) microwave studio to execute its four characteristic modes at 900 MHz. With the implementation of minor changes in the GCUF logo, optimal conjugate impedance matching with the RFID chip has been achieved. The impedance, reflection coefficient, and far-field pattern are examined through CST. The logo tag antenna is fabricated using a Rexin substrate (artificial leather) coated with conductive paint and a passive UHF RFID Alien Higgs H3 chip attached to the logo for impedance matching. The proposed design has been simulated with a human body model. The read range of the fabricated prototype is tested on different objects, like a notebook, T-shirt, and bag. The measured read range demonstrates the robustness of the proposed logo design across various distances: 3 m for a notebook and bag, and 2 m for a T-shirt, with RSSI values of −61 dB, −59 dB, and −62 dB, respectively.