Chipless RFID Tags as Microwave Sensors for Delamination Detection in Layered Structures.

Monitoring multilayer dielectric structures for defects, such as disbonds and delaminations, is an ongoing issue in a number of critical applications. Chipless RFID tags can be used to address some of the issues pertinent to detecting these defects. This work explores the use of chipless RFID tags for this application and investigates the effects of tag operating frequency, material thickness, material dielectric properties, and delamination thickness on this approach's sensing capabilities.

Corner Reflector Based Misalignment-Tolerant Chipless RFID Tag Design Methodology.

Chipless RFID is a relatively new and rapidly growing field that faces some practical implementation challenges. One of these challenges is extreme sensitivity to small misalignments between the tag and the reader antenna. These tilts and translations can lead to erroneous responses which can then be interpreted as incorrect IDs or sensing parameter values in identification and sensing applications, respectively.

Review of advances in microwave and millimetre-wave NDT&E: principles and applications.

Microwave and millimetre-wave non-destructive testing and evaluation (NDT&E) has a long history dating back to the late 1950s (Bahr 1982 ; Zoughi 2000 ; Feinstein 1967 ; Ash 1973 In ; Auld 1981 , 149-154; Case 2017 ). However, sustained activities in this field date back to the early 1980s (Zoughi 1995 , 71-74; Zoughi 2018 , 1051-1057; Kharkovsky 2007 , 26-38). Owing to various limitations associated with using microwaves and millimetre waves for NDT&E, these techniques did not see much utility in the early days.

Multi-Bit Chipless RFID Sensing Methodology for Rotation Determination.

Chipless RFID tags can be used for both identification and sensing applications. While binary codes are assigned to the responses of ID tags, they typically are not assigned to the responses of sensing tags. Instead, changes in tag response characteristics, like notches, are related to a sensing parameter.

Application-Adaptable Chipless RFID Tag: Design Methodology, Metrics, and Measurements.

The field of chipless RFID is growing due to the cost effectiveness, simplicity, and versatility of the technology. Typically, chipless RFID tags utilize a single type of resonator in their design and are designed for a singular application. These design practices are limiting both in terms of versatility and practicality.

Utilization of Microwave Imaging for Chipless RFID Tag Reading and Verification - A Hybrid Approach.

Chipless RFID tags can operate in the time-, frequency-, or spatial-domain, each of which comes with its own limitations and challenges. This work proposes and provides a proof-of-concept for a hybrid spatial- and frequency-domain approach that combines frequency-domain information of the resonators of chipless RFID tags with microwave synthetic aperture radar (SAR) imaging. In this way, the tag resonators can serve a dual identification and sensing purpose allowing for tags to become more information-dense.

Measurement of Inkjet-Printing Parameters for Accurate Chipless RFID Tag EM Simulation.

The use of Chipless RFID tags has been increasing for many applications, especially for structural health monitoring (SHM) applications where they are either affixed or embedded in materials and structures. The practical utility of chipless RFID is dependent upon the ability to manufacture tags in a cost-effective manner. One approach for achieving this is through the use of an inkjet printer and conductive ink.

Application-Adaptable Chipless RFID Tag.

Chipless RFID has gained prominence due to its application versatility and cost and complexity advantages over traditional RFID. However, chipless RFID tags are typically designed for a specific application instead of being deployable for a multitude of applications. In this paper, a new approach to adaptable chipless RFID tag is proposed that can be optimized for a variety of applications, including materials characterization with tags as embedded sensors.

Embedded Chipless RFID Measurement Methodology for Microwave Materials Characterization.

The use of chipless RFID is rapidly growing with applications for both identification and sensing purposes. In existing chipless RFID technology for identification purposes, radar cross-section (RCS) vs. frequency information is often used to create a unique identification (binary) code of 1's and 0's.