Chipless Microwave RFID based on Printed Circuit Technology: Sensor Integration, Tag Localization and Robustness Optimization

• Applicants: Professor Dr.-Ing. Rolf Jakoby; Professor Dr.-Ing. Martin Vossiek
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2013 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 240171326

Among the key requirements for wireless sensors are low cost, robustness, durability, identification capability and large reading ranges, where possible with precise localization and range boundaries.Although many conventional solutions based on active semiconductor components can meet these criteria, they are limited by power-supply, durability, and robustness issues. When combined with suitable sensor concepts, chipless RFID technology has the potential to convincingly overcome these challenges. One of these key challenges is the integration of powerful sensor technologies into RFID.Basis of the proposed project (renewal proposal) are the results from the precursor project, where major advances in system modeling and implementation of new concepts enable the highest data capacities worldwide for chipless time-domain (TD-) RFID. Moreover, a new reader architecture based on the well-known FMCW principle, was developed, and implemented in a highly compact andmodular fashion.The general objective of the new project is the theoretical and experimental investigation of novel, chipless, TD-RFID systems with advanced sensor capabilities, focusing on integration of highly accurate temperature sensors on chipless TD-RFID tags as well as on tag- and reader-system concepts for 3D-tag localization and precise reading-range boundaries.The integration of high-precision temperature sensors becomes possible by a novel hybrid time frequency coding method. Hence, ID and sensor data can be simultaneously transmitted by decoupling parts of the signals due to a notch filter with the highest Q factor on the tag. The sensor data is decoded by the filter resonance frequency, while Q factor optimization is key to the accuracy of the temperature measurement.The wide bandwidth of the compact UWB reader system, developed in the precursor project, makes it an ideal candidate also for localization tasks. In the new project, a portable handheld reader, generating synthetic apertures, and thus, providing new options for 3D localization, will be developed. The trajectory of the reader will be determined by inertial sensors. Innovative MIMO reconstruction techniques, based on the differentiation of RFID signal-phase values spatially and/or over time for tolerancing the inertial sensors w.r.t. drift and offset, will be investigated.Besides low-cost, durability, robustness and non-line of sight operability, this novel chipless TD-RFID sensor system exhibit multi-functional characteristics, including ID as well as highly accurate sensing and localization. With these, it goes beyond competing systems such as barcodes and SAW-RFID, opening up new applications, particularly in robotics and automation.

• DFG Programme: Research Grants