Holographic MIMO antenna systems

• Applicant: Professor Dr.-Ing. Christian Waldschmidt, since 2/2024
• Subject Area: Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 492998157

In recent years, multi-channel antenna systems for sensor and communication applications in the millimeter wave range have increasingly gained relevance. The decisive factor for this development was primarily the enormous advances in silicon-germanium (SiGe) and CMOS semiconductor technology, which meanwhile enable highly miniaturized and cost-effective realizations of complete transceiver topologies in this frequency range. The latest developments show that multi-channel system-on-chip (SoC) solutions may shift a large portion of the system complexity to the circuit level. Although current semiconductor technologies make it possible to implement active circuits at operating frequencies above 500 GHz, comparable MIMO systems above 150 GHz are usually characterized by a considerably more complex design with a lower scope of performance. In addition to the challenge of realizing a sufficiently high output power in the transmit path or a low noise figure in the receive path by integrated millimeter and submillimeter wave transceivers, the reasons for the limited performance can also be found in the highly lossy and tolerance-sensitive packaging and interconnection technology. Furthermore, nowadays there are hardly any compact antenna systems above 150 GHz available that have broadband, efficient and at the same time highly directive radiation characteristics as classic design approaches for the radiating elements are often inadequately compatible with the available semiconductor or packaging technologies for the upper millimeter wave range.A possible solution to the last-mentioned restriction is provided by leaky wave antennas that are based on the holographic principle. With an appropriate design, this type of antenna does not have any resonant behavior facilitating the implementation of highly efficient antennas with a large effective area and bandwidth. However, this requires a low-loss material composition for the antenna structure, which can be accomplished using an antenna-in-package (AiP) approach. Likewise, the integration into a packaged millimeter wave frontend is favored by the planar and simple design of holographic antennas.Within this research project, the new concept will be thoroughly investigated for the use in MIMO radar sensors. In comparison to classic MIMO radar systems using a minimum redundancy array approach, the holography-based radiation diagram synthesis offers completely new degrees of design freedoms, as it does not rely on the position-dependent superposition of individual radiation diagrams. The major objective is the fundamental investigation of holographic multi-port antennas, from which a scalable and flexible synthesis process is to be derived. Finally, the developed design methodologies will be verified experientially by the realization of several passive and active antenna prototypes.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr.-Ing. Tobias Chaloun, until 1/2024