We are talking with one of the CROWN experts, Mr. Antonio Nanni from Leonardo, who is the head of the “MMIC Characterizaion, Modelling and Qualification” Unit in the Microwave Lab Engineering Departement.
Antonio, what are the main responsibilities and activity areas of Leonardo in the CROWN project?
Leonardo participates in the overall project, from CONOPS definition to system architecture and from technology studies to system brick components design and implementation.
In the CROWN project, Leonardo leads the Work Package (WP) on Transmit Receive Module (TRM) architecture, design, and test. Leonardo’s main contribution is to provide the development, assembly and test of the new generation Transmit/Receive Module prototype, core building block of the CROWN system. In the development of TRM components, one of the main Leonardo contributions is in improving and demonstrating on emerging technologies (Gallium Nitride, GaN) adopting EU foundries and in particular the Leonardo Foundry with its GaN process.
And what were the main challenges that you were experiencing during this project regarding the development of the Transmit/Receive Module (TRM)?
The main challenges that engineers and scientists encountered during the development of CROWN Transmit/Receive Modules can be synthetised in three main topics:
Wideband Design: developing TRMs that operate across a wide frequency range are challenging. Ensuring consistent performance and impedance matching across the entire bandwidth is crucial. Guaranteeing ultrawideband application together with high IBW generates more complexity in the TRM architecture. Moreover, a wider bandwidth means a larger noise floor. Maintaining a high SNR across the entire bandwidth is crucial for accurate target detection and tracking.
Power Handling: TRM for Radar Application needs to handle high power levels, which can generate heat and require efficient thermal management to prevent damage or degradation. TRMs requires sophisticated integration and packaging solutions to accommodate a wide range of frequencies and maintain thermal stability. This adds complexity to the design process.
European technology assessment: 0ne of main challenges is developing new European Monolithic Microwave Integrated Circuit (MMIC) components in two different state of art GaN technologies with reduced size, reduced DC power consumption and more optimized electrical performance in ultrawideband frequencies. Hence, developing new wideband MMIC components entirely designed and produced in Europe is significant not only for future realization of MFRS, but also for strengthening the European supply chain.
Could you name the latest technology advancements in the TRC development process that have significantly improved radar systems' performance capabilities on the battlefield in recent years?
TRMs are crucial components of radar systems, and advancements in their design and technology have a significant impact on radar performance. Here are some notable advancements:
GaN Technology: Gallium Nitride (GaN) semiconductor technology has seen increased use in TRMs. GaN offers advantages such as higher power density, increased efficiency, and broader bandwidth compared to traditional materials like Gallium Arsenide (GaAs). This allows for more powerful and versatile radar systems.
Increased Integration: Advancements in packaging and integration have led to more compact and lightweight TRMs. This is particularly important for airborne radar systems, where size and weight constraints are critical.
Digital Beamforming: Digital beamforming techniques in TRMs allow for more precise control of the radar beam, enabling rapid beam scanning and adaptive beamforming for improved target tracking and jamming resistance.
Digital-to-Analog Converters (DACs) and Analog-to-Digital Converters (ADCs): High-performance DACs and ADCs integrated into TRMs enable more accurate signal processing, allowing radar systems to extract and process information from radar returns with greater precision.
What trends are recognized on the future battlefield regarding the use of the upper bands on the multifunction systems, like K- and Ka-bands?
The Ka and K frequency bands offer decisive advantages from an operational point of view. They are inherently high-capacity communications. The Ka and K frequency bands allow instantaneous high-bandwidth data transmission. This is essential for communication between military units, transmitting high-definition video, sending intelligence data and more.
They also allow effective field coverage: Radio waves in the Ka and K-bands can pass through and over obstacles, such as buildings and rough terrain, which is important for maintaining connectivity on an ever-changing battlefield. These bands can provide high-resolution imagery and real-time situational data, enabling commanders to make informed decisions quickly.
Furthermore, they are intrinsically resistant to interference. The Ka and K bands are less affected by electronic interference than lower frequency bands. This can be crucial to ensuring military communications remain secure and reliable in hostile environments.
Ka and K bands can also be used for surveillance radar and aerial surveillance systems, which allow military forces to monitor enemy troop movement and spot potential threats at short ranges.
Finally, they are decisive in satellite communications. Such bands are typically used for satellite communications, allowing military forces to maintain a constant connection in remote areas or on the move.
In summary, the Ka and K frequency bands play an important role in modern military operations, facilitating communication, surveillance, and intelligence gathering on a battlefield. For such a reason the integration of these features into a single multifunctional system plays a key role in next battlefield scenarios.
How would you name, what would be the best indicator of success of the CROWN project for you as a scientist and an expert?
In the CROWN mainframe, the project success depends on the development of the system's building blocks and the demonstration of their feasibility within EU supply chain. For these reasons, it is not possible to define a single indicator but in my opinion three Key parameters.
First, the Wideband Capability or the ability of the TRM and Antenna to efficiently cover a wide frequency range, while maintaining stable and accurate performance is a critical indicator. Success involves effective operation across the entire bandwidth without significant compromises, guaranteeing significantly greater instantaneous bandwidths than today systems.
Digital Beamforming Capability: Evaluation and demonstration of digital beamforming capabilities, including rapid beam steering, beam agility, and the ability to nullify interference. Success is measured by robust beamforming performance and consequently by the ability to perform multiple functions concurrently or sequentially.
EU GaN Technology Capability: Gallium Nitride (GaN) semiconductor technology has seen increased use in TRMs for its intrinsically properties that allow for more powerful and versatile radar systems. One of the best indicators is to demonstrate the EU GaN supply chain assurance regarding critical defence technologies and particularly for the domain of multifunction RF AESA-based systems. Adopting EU foundry processes, the best indicator is to demonstrate EU supply chain capability through the design, fabrication, and test of new MMIC families fulfilling the CROWN specifications.
Antonio Nanni received the Ms-Degree with honours in electronic engineering and the Ph.D. in Telecommunication and Microelectronic engineering from the University of Rome “Tor Vergata”. He works at the company Leonardo SpA in the Electronics division since year 2008. He started his career as microwave production and test engineer, focusing his attention on GaAs and GaN MMIC characterization at on-wafer level and FET nonlinear modelling oriented to radar applications. Today he is head of the “MMIC Characterization, Modelling and Qualification” Unit in the Microwave Lab Engineering Department. His actual research is focused on developing ATE system to characterize at microwave frequencies components from transistor and packaged device up to TR module, modelling of new transistor technologies and electronic component reliability and qualification under operative regime conditions.