Concepts for highly integrated silicon millimeter-wave circuits and systems with metrological performance (MilliMess)

• Applicants: Dr.-Ing. Jan Barowski; Professor Dr.-Ing. Nils Pohl
• Subject Area: Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology ; Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 551426719

The primary objective of this proposal is to explore monolithic silicon germanium (SiGe) based integrated circuits and systems for ultra-high precision, high-frequency metrology. The project accompanies the conception and design of integrated circuits and components by a systematic evaluation with respect to undesired error sources and their influence on the performance of the complete measurement system based on them. Vector network analysis is considered to be a case study for system-level evaluation. Since vector network analyzers offer the possibility of full system error correction in the sense of network analysis and consequently allow calibrated and traceable measurements with a very high dynamic range, they are particularly well-suited as high-performance reference systems. In general, the measurement range of vector network analyzers (VNAs) is limited to a maximum of 70 GHz by commercial equipment. To enable measurements at higher frequencies up to about 1 THz, external modules based on discrete waveguide components ("split block") with frequency multipliers, directional couplers, and dedicated downconverters into the intermediate frequency band (IF band) are further processed by the VNA are used. In cooperation between the two chairs, an extension module (110 GHz to 170 GHz) based on a SiGe MMIC has already been developed. This represents the starting point and is suitable as a case study for investigating factors influencing SiGe integrated circuits on high-performance measurements since different circuit characteristics can significantly affect the calibration capability of the module. Since nonlinear and stochastic effects cannot be calibrated, frequency multipliers with high spurious signal rejection and highly linear as well as simultaneously low-noise receive circuits are explored. In addition, transmit amplifiers are investigated with respect to their load-dependent behavior ("load-pull") in order to enable feedback-free integrated circuits. Furthermore, attention is paid to the realization of a front-end with high directivity to enable the separation of outgoing and returning waves in a broadband manner. For this reason, the coupling of adjacent circuit components is also considered. Subsequently, the integration of signal sources to generate test port and local oscillator signals on a chip is investigated. Using integrated on-chip signal sources stabilized by a phase-locked loop enables measurement with additional waveforms, such as fast linear/nonlinear modulated frequency ramps (FMCW methods). These new approaches in the signal processing of IF signals open up new possibilities for system error correction as well as the characterization of time-variant linear DUTs.

• DFG Programme: Research Grants