X-TREME 6G – harnessing the power of microelectronic innovation to explore a whole new side of wireless communication

A substantial part of X-TREME 6G’s initial efforts consists of definining a comprehensive overview of our project scope and platform architecture that will be used for the selected use case scenarios to show the goals of the project. Let‘s get a bit technical, and talk microelectronics!

InP HBT platform

X-TREME 6G will develop a cutting-edge InP HBT microelectronics platform to unlock unprecedented performance for next-generation wireless and optical communication systems.

Indium Phosphide HBTs are the fastest semiconductor technology available today, offering unmatched speed and potential for further scaling – especially as traditional CMOS and SiGe technologies approach their physical limits.

Doing so, we ambition to:

  • Showcase InP HBT’s performance advantages in real-world 6G use cases.
  • Enable hetero-integration with SiGe BiCMOS to drive energy efficiency and reduce system costs.
  • Boost process maturity and manufacturability to support broader market adoption.
  • Open the platform to startups, SMEs, universities, and research institutes.
  • Our target outcomes are the following:
  • fT > 400 GHz, fMAX > 600 GHz, BVCEO > 4V
  • MMIC fabrication for mm-wave and sub-THz RF front ends
  • Validated PDKs up to 300 GHz
  • 99% transistor yield and competitive noise figures

InP HBT are not meant to replace CMOS or SiGe, but will complement them in high-performance domains like >Tb/s optical links and mm-wave 6G systems.

We are looking forward to breaking the cycle of niche adoption and bring this powerful technology to a wider innovation ecosystem.

Terahertz technology

Furthermore, the transition to 6G and terahertz (THz) frequencies (100 GHz to 10 THz) is redefining the boundaries of wireless communication. With the promise of ultra-high data rates and massive bandwidth, THz technologies are key to next-generation connectivity. However, they also introduce significant engineering challenges—particularly in packaging and integration.

Traditional packaging methods, optimized for lower frequencies, struggle with:

  • Miniaturization at THz wavelengths
  • Thermal dissipation due to high power densities
  • Signal integrity and RF performance affected by material interactions

To address these, the industry is shifting toward heterogeneous packaging, combining the strengths of various semiconductor technologies. For example:

  • Indium Phosphide (InP) power amplifiers offer high efficiency at THz frequencies
  • Silicon Germanium BiCMOS (SiGe BiCMOS) transceivers provide low power consumption and high integration density

Antenna-in-package (AiP) platform

X-TREME 6G will make a significant impact in this space. It will develop a holistic antenna-in-package (AiP) platform that integrates all system components—antennas, power amplifiers, transceivers—into a single system-in-package (SiP). This will be achieved using low-cost, large-scale PCB embedding processes, enabling scalable manufacturing up to 457mm x 610mm panels.

Key technical highlights:

  • Proven integration of SiGe transceivers and GaN power amplifiers (as demonstrated in the EU-Serena project)
  • Advanced thermal management via direct thermal vias on the PCB backside, addressing heat dissipation at THz frequencies
  • Ultra-short interconnects for improved signal integrity and RF performance

Importantly, X-TREME 6G‘s platform is fully compatible with FhG-IZM’s Substrate Integration Line, part of the Chips JU APECS heterogeneous integration Pilot Line. This positions our project as a potential early adopter for industrial pilot runs, accelerating the path to commercialization.

In summary, X-TREME 6G is not only solving the technical bottlenecks of THz packaging – it is laying the foundation for scalable, cost-effective deployment of 6G systems. Its innovations in heterogeneous integration and thermal management are paving the way for a future of ubiquitous, ultra-fast wireless connectivity.

SiGe and InP unified hardware development approach

Our project is at the initiative of a unified hardware development approach that leverages the strengths of both SiGe and InP technologies. This approach combines the high integration density of SiGe for complex building blocks, mixed-signal functionalities, and digital periphery functions, with the high-frequency performance of InP front-end ICs, seamlessly integrated using the Antenna-in-Package (AiP) platform.

AiP technology is a game changer for mmWave and sub-THz Communication, it offers several advantages over traditional on-chip antenna solutions, among which:

  • Higher Bandwidth-Efficiency Product
  • 3D Stack Integration
  • Reduced Package Parasitics

Therefore, X-TREME 6G will achieve significant performance gains compared to existing Silicon-only millimeter-wave phased array demonstrators. Indeed, our project targets a 10-15 dB dynamic range enhancement by:

  • Increased Output Power
  • Improved Efficiency
  • Enhanced Linearity
  • Reduced Noise Performance

By combining the high breakdown voltage, high-speed and low-noise characteristics of the InP technology with the high integration density and high performance of the SiGe technology within a seamless integration platform with a chip embedding approach, X-TREME 6G will reach highly ambitious goals, towards significantly enhancing overall system performance compared to state-of-the-art technology.

Doing so, X-TREME 6G will develop several demonstrators showcasing the capabilities of the proposed technology platform, paving the way for real-world applications:

  • D-band TX/RX Phased Array for JCAS
  • H-band Demonstrator, to explore the potential of even higher frequency bands for point-to-point backhaul scenarios and other high-bandwidth applications.
  • Q/V-band SATCOM TX/RX Phased Arrays, to showcase the superior integration capability and NTN application scenarios of SiGe technology.

By combining the strengths of advanced SiGe and InP technologies, X-TREME 6G will develop high-performance, low-power, and highly integrated transceivers for mmWave and sub-THz frequencies. Our focus on AiP technology and its targeted performance enhancements will pave the way for the realization of 6G’s ambitious goals, enabling a future of seamless connectivity and unprecedented communication capabilities.

Want to keep track of how X-TREME 6G will harness the possibilities of microelectronics to revolutionize wireless communication in Europe? Stay tuned, and connect with us on LinkedIn, where we regularly publish updates on the project’s status and advancements.

X-TREME 6G project has received fundings from the Smart Networks and Services Joint Undertaking (SNS JU) under the Horizon Europe research and innovation programme under Grant Agreement NO 101192681.