Long-range RFID Research Articles

Design and Fabrication of Long-range UHF RFID Reader Antenna with Protection Cover

Design and Fabrication of Long-range UHF RFID Reader Antenna with Protection Cover

4D mmW/5G Metasurfaces and Wireless Sensors Combining Additive Manufacturing, Morphing and ML Technologies

The paper will introduce fully printed 4D metasurfaces and wireless sensors operating up to 5G/mmW frequency range. Multiple morphing (shape-changing) approaches will be presented for massively scalable additively manufactured implementations , while modulation, signal redirection and energy harvesting features will be thoroughly covered in terms of integrability, flexibility and power consumption requirements. The talk will also refer to multiple reconfigurable intelligent surfaces (RIS) being enabled by newly reported fully printed planar lenses (Rotman, Van Atta, …) and dielectric reflectarrays enabling ultra long interrogation ranges when combined with “zero-power” backscattering interrogation techniques. Major challenges of flexible hybrid electronic implementations as well as ultra-low-power printable structures for self-diagnostic and anti-counterfeiting packages will be discussed in depth and numerous ML techniques will be comparatively evaluated for their optimization, calibration and on-demand reconfigurability. The paper will conclude with fully printable mmW/5G RF modules for wireless sensing applications spanning a wide range of fully passive tags to energy autonomous long-range RFID systems and low-cost miniaturized tags for orientation and rotational sensing for VR applications as well as environmental sensing and structural health monitoring.

Circular wire-bundle superscatterer

Scattering cross-section is one of the main properties, characterizing an object in wireless applications. Resonant phenomena increase the electromagnetic visibility of a scatterer while keeping its footprint small. However, the single-channel limit or Chu-Harrington limit imposes a tight upper bound on a scattering cross-section of subwavelength objects. Being derived for a dipolar response, this limitation can be bypassed if several resonances of a structure are spectrally co-located and contribute constructively to the scattering. Subwavelength structures, obeying this design concept though hardly achievable in practical implementations, are called superscatterers. Here we demonstrate a superscatterer realization, based on a circular bundle of vertically aligned metal wires, optimized to demonstrate 5 multipoles, resonating at nearly the same frequency. As a result, the scattering cross-section becomes 12 times larger than object's geometrical cross-section. Owing to the multipolar multiplexing within the structure, the scattering is 7 times larger than the dipole single-channel limit. Additionally, as a result of the constructive interference of several multipoles, scattering directivity up to 10 dB is observed. Wire-bundle superscatterers may become an attractive architecture for many applications, including compact directive antennas, radar chaff and beacons, long-range RFID tags, and many others.

UHF RFID Tag Design Using Theory of Characteristics Modes for Platform-Tolerant and Harsh Metallic Environments

This paper presents a wideband, long-range RFID tag antenna design with platform tolerant features using characteristic mode analysis (CMA). The proposed design consists of a two-layer structure, that are separated by an air gap. The upper layer consists of T-match and dual loop-based meandered antenna optimized for achieving long read range characteristics in free space/low permittivity dielectrics. The second layer consists of multi-resonant strips printed on a grounded substrate carefully designed using CMA for producing multi-resonant modes in the required UHF RFID band. The multi-resonant strips help in achieving wide bandwidth and isolation between different environment surfaces. This tag antenna provides a wide bandwidth ranging from 900 – 940 MHz that covers both the US UHF RFID band (902 – 928 MHz) and the upper European UHF RFID band (915 – 921 MHz). Moreover, this design achieved a read range of 14.7 m in free space, 14 m on a metal plate, and 13 m on wood, and glass. Furthermore, the proposed antenna was also tested in harsh metal environments such as car number plates and cargo metallic containers. Therefore, the proposed tag can be used for tagging metallic containers, wood containers, and other harsh platforms for cargo management, Asset tracking, supply chain visibility, and Internet of Things (IoT) Applications.

A Phase-Based Ranging Method for Long-Range RFID Positioning With Quantum Tunneling Tags

This work demonstrates the ability to extend the positioning range of low-powered RFID tags to distances usually not achievable with other wireless or conventional RFID technologies. The technique is performed through a Received Signal Phase (RSP)-based method on a 5.8 GHz backscatter tunneling tag, in multipath-rich indoor and outdoor environments, at distances up to 35 meters from the reader. Distance errors as low as 0.1% of the total reader-to-tag distance were observed with average errors of 0.8% and 0.6% for indoor and outdoor environments, respectively. Compared to Received Signal Strength (RSS)-based techniques, the average distance estimation accuracy is improved by a factor of 51 and 38 for indoor and outdoor environments, respectively. Moreover, an Effective Isotropic Radiated Power (EIRP) of only 10.5 dBm and a biasing power for the tunneling tag of only $21.3~\mu \text{W}$ at 80 mV promise a low-power, long-range sub-meter scale positioning technique with a projected maximum range over 1 km.

RFID Backscattering in Long-Range Scenarios

This paper presents a 5.8-GHz RFID tag that, by exploiting the quantum tunneling effect, significantly increases the range of backscatter radio links. We present an electronically simple Tunneling RFID Tag characterized by return gains as high as 35 dB with link sensitivity as low as −81 dBm. Without relevant increase in power consumption, the tunneling tag enables a host of new wireless sensors and Internet of Things applications that require both the long range of conventional wireless links and the low power consumption of semi-passive RFID devices. Selected measurements demonstrate a reader-to-tag separation distance 10 times higher than the maximum range of ideal semi-passive tags. Moreover, the collected experimental results allowed to outline a mathematical model demonstrating how the long-range RFID tag prototype can achieve distances unusual for this technology.

A Scalable and Hybrid Location Estimation Algorithm for Long-Range RFID Systems

Localization of assets is a critical component of smart building applications. This problem involves a lot of challenges and gets even more challenging when a consistently high level of accuracy has to be ensured while employing long-range RFID readers. In general, these antennas are placed so that there is some level of overlap of their ranges of influence, in order to support asset tracking with high precision. However, it is desirable to reduce the level of overlap when employing multiple readers for large-scale asset tracking, due to the high cost of these RFID readers and antennas. In such scenarios, it is important to maintain accuracy while increasing the coverage area of the readers, and for this a robust localization algorithm is necessary. This paper describes a novel hybrid indoor localization algorithm that combines the transmission power level control and the signal strength information in an intelligent manner to locate assets accurately. The algorithm does not require much calibration and is easily scalable. Additionally, it allows for both coarse and fine-grained location estimation depending on application requirements. Our experiments in real indoor environments, and with different degrees of overlap between long-range RFID antennas show that our algorithm provides higher accuracy in comparison to other algorithms, and is also consistent.

A Wireless-Powered IR-UWB Transmitter for Long-Range Passive RFID Tags in 90-nm CMOS

An impulse radio ultrawideband (IR-UWB) transmitter (TX) intended for long-range passive radio-frequency (RF) identification tags is presented. It is wirelessly powered by an ultrahigh-frequency (UHF) signal. A 128-bit pseudonoise code is transmitted when enough energy is harvested. A new on-off-keying multicycle energy-efficient IR-UWB pulse generator (PG) is proposed, and a co-design with power management circuits is introduced to improve the system supply noise performance. A novel injection-locking divider co-designed with an RF voltage rectifier is proposed to eliminate the injection input resistive load that exists in some designs; otherwise, the input sensitivity would be degraded. A proof-of-concept prototype is fabricated in a TSMC 90-nm CMOS process. Measurements show the TX input sensitivity to be approximately -17.5 dBm with a 900-MHz UHF input. The measured PG output swing is 195 mV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p-p</sub> with a -10 dB bandwidth of approximately 3.4 GHz.

Student Attendance Management System Based on RFID and Imaging Processing

This paper raise a latest and original design for the student attendance management system, which is helpful to strengthen teaching management and improve the quality of teaching. It has not only great significance and also broad application prospects. In this system the 915M long-range RFID tag is used and no access control is set, enabling students to access conveniently without punching card, that is effective to avoid queuing. Through the camera fixed overhead, the program can make real-time image acquisition and processing to count the number of students entering and going out. Combined with the RF reader, it can avoid the appearance of one student carrying muti-card to punch card instead of others.

Compact printed double-folded inverted-L antenna for long-range RFID handheld reader

A novel compact printed double-folded inverted-L antenna is presented. The radiator is modified from a printed inverted-L antenna by extending and folding its radiated arm. A unidirectional radiation pattern is obtained as the radiator is mounted on a vertical printed rectangular ground. A slit etched on the ground of proper length and position is used to improve antenna directivity and suppress backward radiation. Measured results indicate that the proposed antenna has a good impedance characteristic (9% for return loss less than 10 dB), excellent front-to-back ratio and forward gain of 5.09 dBi. The antenna is applicable for long-range RFID handheld reader application.