Solid state electronics and photonic integration for THz communications

• Applicant: Professor Dr.-Ing. Ingmar Kallfass
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 491277347

Data traffic over wireless networks keeps following an exponential growth rate. The COVID pandemic will almost certainly have accelerated this growth and surely have a lasting effect on the digitization of business and private exchange. With the road open towards early 6th generation of cellular systems (6G), expected for 2030, Europe initiated strategic actions to push forward European-based technologies for the next generation core wireless networks. Leveraging on on-going strong action established in this field by the applicants, we propose a disruptive step in combining leading French and German technologies in a system-oriented approach for THz communication. The SOLITONIC project targets a THz transmitter at 300 GHz with up to 200 Gbit/s. Using the best features of photonic and electronic devices, we propose a combination of two THz technologies, featuring highest data-rates (photonics) and highest output linear powers (electronics). This approach will enhance the exploitable dynamic range of the THz transmitter, which is today’s major performance bottleneck in THz systems, and enable beyond state-of-the art in both THz system-level testing as well as THz link demonstrations. The main objective is the optimally-matched custom design of multi-channel uni-travelling carrier (UTC) photodiodes and wideband power amplifier MMICs based on InGaAs HEMT technology to achieve a new class of 300 GHz transmitter. It includes a co-integration of:a) For the French partner (CNRS, Lille) the design of multi-channel THz UTC photodiodes for 300 GHz down-conversion through photonic mixing of multiple laser lines, optimized for 250-350 GHz operation.b) For the German partner (University of Stuttgart), the design of InGaAs HEMT active amplifiers will enable to reach the required wideband linear output powers for km-range transmissions.In order to unlock the full potential of the electronic-photonic combination, all components will be custom-designed for optimum gain and linearity partitioning as well as interstage impedance matching. After co-integration of the two core chips, we will make use of optical pre-distortion techniques to optimize the performance and signal integrity at the combined UTC+amplifier output, building on unique photonic THz measurement techniques developed in the prior art of the two partners.

• DFG Programme: Research Grants
• International Connection: France
• Cooperation Partner: Professor Dr. Guillaume Ducournau