Smart RF Systems based on Artificial and Functional Materials

Passive chipless RFID and wireless sensor tags (i. e. tags without active power supply and without silicon ‘chip’-based information handling) allow for identification and measurement in environments that cannot be accessed by ‘conventional’ chip-based approaches, either for technical or economical reasons.

Team Leader: Alejandro Jiménez Sáez

The research of the microwave engineering group in this field is focused on novel tag designs and concepts for passive chipless RFID and wireless sensors based on the high-Q resonator concept. An example can be seen in the temperature sensor for machine tools shown in the following photo, as well as a video of the working principle of a former sensor design.

Dielectric resonator high temperature sensor demonstration

Of special interest is the use periodic structures such as the Bed of Nails and Photonic Crystals for the realization of frequency-coded retroreflective structures, i.e., structures that passively color and reflect mm-Wave and THz waves. These tags are developed within the project SFB/TRR Marie and in collaboration with partners from the Universität Duisburg-Essen and the Ruhr-Universität Bochum. An overview of the design, fabrication, and characterization of such a retroreflector can be seen in the following video.

Furthermore, the use of periodic structures for the realization of tunable components is being investigated in collaboration with the Tunable Microwave Devices’ group. An example of a phase shifter integrated in a Bed of Nails can be seen in the images below.