A Control Unit for a Very Compact Quantum Gyroscope
GIRAFFE – Industrial Applicability Proof of Quantum Sensing
GIRAFFE (GYRoscopes for Autonomous driving and Flight assistancE) is a research project dealing with quantum sensing technologies, co-funded by the Austrian Research Promotion Agency (FFG). The project aims to develop a high-performance embedded system to control a quantum gyroscope, leveraging an RFSoC (Radio-Frequency System-on-Chip) subsystem.
Cosylab is a partner in the GIRAFFE consortium, led by Silicon Austria Labs, Austria’s premier research centre for electronics-based systems. Specifically, GIRAFFE will advance the technology of diamond NV-centre gyroscopes and bridge the gap between experimental research and industrial applications of these sensing devices. By using a fully-functioning demonstrator, the final objective is to demonstrate the applicability of such sensors for the practical use case of self-governing navigation in driving and flight.
What is a Gyroscope
Gyroscopes are sensors that detect rotation and angular velocity about three orthogonal axes. They measure the effects of the Coriolis force that acts on an object in motion within a reference frame that rotates with respect to an inertial frame. The force is perpendicular both to the velocity relative to the rotating frame and to the angular velocity of the rotating frame relative to the inertial frame.
Quantum gyroscopes detect the Coriolis force by measuring the phase shift of a matter wave produced by a beam of atoms that is first split and then recombined after rotation.
Inertial-based Navigation and Quantum Technology
With recent advances in autonomous terrestrial and aerial vehicles, there is an increasing need for reliable inertial-based navigation, independent of satellite-based referencing. An essential component of these systems is a gyroscope. The current mass-produced MEMS (Micro-Electro-Mechanical-System) gyroscopes used in automotive applications are reaching their inherent limits of drift and sensitivity; therefore, they do not meet the demand for tomorrow’s navigation-grade performance.
Sensing performance can be fundamentally increased by exploiting the intrinsic quantum properties of fundamental particles. The GIRAFFE project aims to study sensing principles based on the precession of nuclear spins in diamond nitrogen-vacancy (NV) centres and implement them in a solid-state platform.
Challenges for NV-centre Quantum Gyroscopes
At present, research efforts on diamond NV nuclear-spin gyroscope technology have been undertaken mainly by quantum physics communities with specialised research infrastructure. There has been little transfer of experimental know-how between specific research institutions and the industry.
The challenge of transitioning the technology from the lab to real-world applications lies in integrating multiple large high-end instruments into an embedded electronic system. The latter must be shrunk to the size of a compact and miniaturised battery-powered unit to be practical in industrial use.
The Key-building Blocks of the GIRAFFE Demonstrator
A small-scale demonstrator for a quantum sensor unit with NV-centre diamond technology can be broadly divided into four subsystems — key-building blocks — each from a fundamentally separate domain:
- optical subsystem;
- magnetic subsystem ;
- multichannel RF/MW generation, amplification, and delivery;
- the digital electronic control unit
- (orchestrates the entire sensor readout procedure);
GIRAFFE Pushing the Envelope in Inertial Sensing
GIRAFFE uniquely combines quantum sensing technology with a holistic expert approach to design and integration at magnetic, optical, and RF (radio frequency) system levels and practical, domain-specific knowledge of advanced driver assistance systems (ADAS) use cases.
The project extends the fundamental knowledge in quantum physics and the performance of inertial sensing technology. Its results will be of significant relevance for the automotive and, potentially aerospace/defence industry.
Cosylab has considerable expertise in FPGA (Field Programmable Gate Array) applications and microwave generation, including multi-frequency generation ranging from MHz to GHz. In the quantum domain, for example, Cosylab has developed the control electronics for Qnami’s MicrowaveQ system, the first commercially available scanning NV microscope for atomic-scale analysis of magnetic materials.
Building Blocks for GIRAFFE’s Embedded Electronics
- RFSoC FPGA;
- digital sequencing circuitry;
- a multichannel high-speed analog interface with 500 MSPS;
- digital signal processing (digital filtering, lock-in detection);
- multichannel RF generation with controllable phase, amplitude and frequency;
- a compact RF amplifier;
- integration of a high-frequency laser pulsing board using state-of-the-art GaN technology
- (the subunit developed and provided by Infineon);
- customised diamond sample preparation with structures for high photon collection efficiency;
- compact optical system with confocal detection capabilities;
- small integrated RF antennas;
- a Halbach-like magnet system for DC-bias magnetic field;
The GIRAFFE Control Unit is Adaptable and Fast
Cosylab is to design and develop the digital electronic control unit of the GIRAFFE prototype. Based on the project’s simulations and system-integration concepts, Cosylab will cover the key building blocks required for the embedded electronics of the compact nuclear-spin diamond gyroscope at the heart of the GIRAFFE device.
First and foremost will be the design and realisation of the RFSoC FPGA platform. All the key-building blocks will be individually tested and characterised, then used as the base for the development and assembly of the final demonstrator. Cosylab will also develop demonstrator miniaturisation approaches that consider additive manufacturing possibilities.
FPGA Expertise is Key to GIRAFFE
Cosylab’s digital electronic control unit for GIRAFFE will orchestrate the entire sensor readout procedure. It will generate multichannel nanosecond pulses to trigger the high-power laser with sub-µs pulses via external driving boards using state-of-the-art GaN transistors.
The control unit will also trigger the radio-frequency pulses by generating a multichannel RF signal with controllable phase, frequency and output power. RF generation will be entirely embedded and cointegrated with the rest of the electronics by using a modern RF system-on-chip FPGA platform. The latter will ensure compact implementation and high performance with good phase and frequency stability.
An external amplifier and delivery system will be developed by project partners, for which an antenna structure or micro-coils might be integrated directly onto the diamond’s surface.
Furthermore, the control unit shall provide high-speed, analog-to-digital conversions of at least two photodetectors. A balanced detection or a lock-in detection will be used to detect the minute luminescence signal buried in noise. The control unit will possess enough processing power to assure high-speed real-time calculation of the angle rates and provide external interfacing to be integrated into the existing platforms.
The Future of Quantum Technology in Inertial Guidance
Despite their potential, many challenges remain to overcome in making quantum gyroscopes practical for widespread use. One of the concerns is improving the stability of these sensors, which is critical for maintaining their accuracy over long periods. Another issue is reducing their size and cost, which is vital for their adoption in commercial applications.
GIRAFFE project will address these issues by combining the protracted accuracy of diamond NV nuclear-spin technology with a high-performance embedded RFSoC FPGA platform. The two will be packaged together in a practical, miniaturised battery-powered unit tailored for manufacturing and industrial use.
The market for quantum gyroscopes is expected to grow significantly in the coming years. According to a report by the Business Research Company, the global gyroscopes market is expected to grow from 2.93 billion USD in 2023 to 3.82 billion USD in 2027 at a CAGR (Compound Annual Growth Rate) of 6.8%. This increase is driven by rising demand for high-precision and reliable inertial navigation systems, particularly in the aerospace and defence sectors, such as the production of unmanned aerial vehicles (UAVs) and drones for surveillance and warfare.
Scope of Cosylab’s GIRAFFE Technical Work
- VHDL hardware design of FPGA RFSoC embedded electronic platform;
- design of integrated electronics for high-speed laser pulsing and RF amplification;
- wire-bonding / homemade coiling setup;
- scientific programming (advanced signal processing);
- individual characterisation of key-building blocks;
- demonstrator performance-testing;
ABOUT THE AUTHORS
Jernej Kokalj is an electronics engineer specialising in FPGA development and project management. After work, he is a track and field coach for elementary school students at a local sports club. He enjoys working on leading-edge FPGA applications, such as next-generation PET scanners, microwave devices for brain-stroke detection — and quantum-based microscopes, gradiometers and gyroscopes.
He loves various sports and cherishes road trips with friends.
Cosylab is a member of a consortium led by Silicon Austria Labs, with the University of Stuttgart, Beyond Gravity Austria, AVL List GmbH, 4ActiveSystems, and Infineon Technologies Villach. This project is funded within the framework of Quantum Austria by the Austrian “Nationalstiftung für Forschung, Technologie und Entwicklung” (National Foundation for Research, Technology and Development), the FFG and FWF, with support of the Federal Ministry for Science and Research (BMBWF).
