Planar antenna arrays with electronically reconfigurable apertur

• Applicant: Professor Dr.-Ing. Christian Waldschmidt, since 2/2024
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 444833493

In recent years, electronically steerable antennas for sensor and communication systems in the millimeter wave range have increasingly gained relevance. While for a long time the economical barrier for such system architectures was high due to their considerable degree of complexity, many electrical steerable antenna arrays have been established in civil and commercial application scenarios nowadays. Representative for the multifarious use, automotive radar sensors at 77 GHz, terrestrial radio links at 25 GHz (5G)/ 60 GHz and the mobile satellite communication at 30 GHz can be mentioned as prominent examples. They owe their popularity to dramatic advances in the silicon germanium (SiGe) semiconductor technology enabling the highly miniaturized and cost-effective realization of transceiver topology in this frequency range. Recent developments show that multichannel system-on-chip (SoC) solutions may absorb large portion of the overall system complexity. Although the vast functional range accommodated in the analog and digital circuitry of those antenna systems is increasing continuously, the extension of features directly within antenna elements is not being observed. Since electronical steerable antenna arrays change their properties inherently while manipulating the complex excitation coefficients, a compromise on the element performance e.g. for different scanning angles has inevitably to be made during the design process. In principle, the cause-effect relationships for these passive structures are well-known from literature being described in the spatial domain by the superimposition of coupling coefficients to adjacent antenna elements. In this research proposals a novel planar antenna concept for millimeter wave frequencies is investigated fundamentally in which the aperture of antenna array is supposed to be reconfigurable electronically. Through this approach, it will be possible for the first time to conduct the beam synthesis by the complex element excitations as well as by the electrical reconfiguration of the mutual element interactions. The proposal will offer a completely new degree of freedom in designing planar antenna arrays. Apart from the beam synthesis by the excitation of the individual elements, this methodology opens the possibility to reduce specifically the gain degradation at larger elevation angles over a wide frequency range by the adaptive reconfiguration of the aperture. Furthermore, antenna arrays applying the idea of non-linear and active controllable apertures will be investigated in order to suppress interference signals as a function of their (spectral) power density, modulation form and angle of incidence without using classical beamforming techniques.

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