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. The benefits and challenges of this approach are discussed in the context of a collection of simulations and measurements using two new tag designs.