3D Printing of Metallic Antennas for 0.5 THz to 6 THz (3D-@-6T)

• Applicants: Dr. Katja Höflich; Professor Dr.-Ing. Christian Waldschmidt
• Subject Area: Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 576297090

The 3D-@-6T project focuses on a novel 3D printing process based on localized electrochemical metal deposition for the fabrication of THz antennas. The 3D printing technology enables the deposition of pure copper with micrometer precision, thereby opening up—for the first time—the frequency range up to 6 THz for direct on-chip integration or interconnection of antennas. This means the 3D-@-6T project is entering uncharted scientific territory and addressing key research topics in high-frequency technology: i) Losses: Antenna integration can be carried out directly connected to the chip’s backend, minimizing transmission losses between signal generation and the antenna. ii) Component size: At the same time, vertical 3D antenna designs are possible, requiring only a fraction of the chip area compared to planar designs, making a decisive contribution to miniaturization. iii) Functionality: The vastly expanded parameter space for 3D designs allows for the realization of very broadband antennas with excellent radiation properties. The antennas are designed and modeled using full-wave electromagnetic (EM) simulators. The 3D printing technology is being researched in terms of its material basis and design principles for highly efficient antennas. Two novel methods for assembly and interconnection technology are being implemented. The high-precision pick-and-place transfer of printed antennas using a dual-beam instrument allows for rapid testing of new design concepts in a rapid-prototyping approach. The crucial technological breakthrough, however, is the localized electrochemical deposition of 3D antennas with micrometer accuracy directly onto pre-processed chips, without any additional processing steps such as sintering or metallization. To achieve these ambitious project goals, the 3D-@-6T project combines the specialized expertise and research equipment of two project leaders in an interdisciplinary approach. Prof. Christian Waldschmidt contributes his experience in the design of integrated antennas at several hundred GHz, in exploring assembly and interconnection technology (AVT) concepts up to 500 GHz, and in antenna measurement technology up to the THz range. Dr. Katja Höflich conducts research on the design and fabrication of complex 3D structures and optical antennas for applications in photonic quantum technology. She brings her expertise in innovative nano- and microfabrication techniques as well as in materials characterization methods. Thanks to this complementary know-how, the 3D-@-6T project is able to open up a new field of research regarding the manufacturing and integration of highly efficient antennas in assembly and interconnection technology in the frequency range up to several THz.

• DFG Programme: Research Grants