The ultra-stable, tunable THz system, developed within the 6G-ADLANTIK project, is based on frequency comb technology and enables carrier frequencies well beyond 500 GHz.
In this approach, a photodiode efficiently converts an optical beat signal derived from lasers with slightly different optical frequencies into an electrical signal through a photomixing process. The antenna structure surrounding the photomixer translates the oscillating photocurrent into a THz wave. The resulting signals can be modulated and demodulated for 6G wireless communications and can be tuned easily over a wide frequency range. The presented system also can be extended for component characterization with coherently received THz signals. A THz waveguide architecture simulation and design, as well as the development of ultra-low phase noise photonic reference oscillators, are also part of the scope of work for this project.
The ultra-low phase noise of the system is enabled by a comb-locked optical frequency synthesizer (OFS) in the TOPTICA laser engine. High-end instruments from Rohde & Schwarz are part of the setup: The R&S SFI100A wideband IF vector signal generator creates the baseband signals for the optical modulator with a sample rate of 16 GS/s. The R&S SMA100B RF and microwave signal generator generates a stable reference clock signal for the TOPTICA OFS system. The R&S RTP oscilloscope samples the baseband signal after the photoconductive continuous wave (cw) THz receiver (Rx) at a sample rate of 40 GS/s for further processing and demodulation of the 300 GHz carrier frequency signal, which will be shown at EuMW 2024.
The 6G-ADLANTIK project focuses on developing components for the THz frequency range based on photonic and electronic integration. Such THz components, yet to be developed, can then be used for innovative measurements and faster data transfers. These components will find applications not only in 6G communications but also in sensing and imaging. Funded by the Federal Ministry of Education and Research of Germany (BMBF) and coordinated by Rohde & Schwarz, 6G-ADLANTIK has brought together the partners Toptica Photonics AG, Fraunhofer-Institut HHI, Microwave Photonics GmbH, Technical University Berlin, and Spinner GmbH.
In addition, Rohde & Schwarz will co-host a full-day workshop at the European Microwave Conference (EuMC) on 22 September 2024 titled Photonic Technologies for Radio Frequency Applications, covering different aspects such as maturity, performance and costs of photonic RF technologies and their potential to compete with existing solutions.