measurement system for OTA characterizations

• Subject Area: Electrical Engineering and Information Technology
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 556949430

In order to characterize the electromagnetic radiation properties of transmitting and receiving units and their components, so-called "over-the-air" (OTA) measurements are carried out. Antennas can be connected directly to an excitation signal. Increasingly, however, highly integrated systems or passive units are also of interest for the Internet of Things (IoT). In general terms, this involves spatially resolved measurement of high-frequency electromagnetic fields in the near field or far field. Such an OTA measurement system consists of an electromagnetically shielded chamber equipped with absorbers. This prevents interference and reflections. In addition, a high-frequency measuring device is required for signal generation and analysis, usually a vector network analyzer. A remote-controlled positioning system is used to spatially resolved record the signals emitted by the test object (typically using measuring antennas). Such a measurement system is being applied for in the project. The size of the chamber is largely determined by the lower frequency. A lower cut-off frequency of 6 GHz was considered here based on the trade-off between available installation space, relevant radio standards and budget considerations, although lower frequencies are desirable and advantageous. The measurement technology and the far-field conditions influenced by the size of the structures determine the upper cut-off frequency. Initially, the range up to 40 GHz is to be covered in order to enable research in the important 5G / 6G frequency ranges around 28 GHz, for example. An extension to higher frequencies is foreseeable (e.g. 76 / 77 GHz for automotive radar) and planned in future projects. The OTA measurement system should therefore be expandable to higher frequencies.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Messsystem für OTA-Charakterisierungen
• Instrumentation Group: 6380 Frequenzanalysatoren, Schwingungsanalysatoren
• Applicant Institution: Technische Universität Clausthal
• Leader: Professor Dr.-Ing. Niels Neumann