GaN mm-wave Radar Components Embedded

Project Information

GRACE

Grant agreement ID: 821270

DOI

10.3030/821270

Project closed

EC signature date 25 October 2018

Start date 1 November 2018

End date 31 August 2021

Funded under

• SOCIETAL CHALLENGES - Smart, Green And Integrated Transport

Total cost

€ 1 742 815,00

EU contribution

€ 1 742 815,00

Coordinated by

CHALMERS TEKNISKA HOGSKOLA AB
Sweden

Periodic Reporting for period 2 - GRACE (GaN mm-wave Radar Components Embedded)

Reporting period: 2019-11-01 to 2021-08-31

Summary of the context and overall objectives of the project

The GRACE project addresses the challenge of environmental impact from the aviation industry by the development of novel surface mount radar components for integration in Enhanced Flight Vision Systems (EFVS) of civil air crafts operating in the frequency range 93-100 GHz.

The Advisory Council for Aeronautical Research in Europe (ACARE) defined stringent targets to be achieved by aircraft technology maturing in 2020 compared to state of-the-art technology of the year 2000. ACARE targets a 50% reduction of CO2 emissions from the commercial flying segment, 40% by greener technologies and another 10% by a more efficient Air Traffic Management (ATM). The GRACE project directs to the ATM segment by introducing more efficient EFVSs. Traditionally, EFVSs are based on a forward looking infrared (IR) camera which gives a thermal image of the world. However, IR sensors are sensitive to environmental factors such as rain and fog. Further, they are not as good as Radars for motion detection. High-resolution motion detection may be fulfilled with a mm-wave (mmW) radar.

Key components in a radar system are Power Amplifiers (PAs) and a Signal Sources (SSs). The realization fo cost-effective mmW PAs and SSs rely on access to short gatelength GaN HEMT MMIC technology. The only process commercially open in Europe is the D01GH/D006GH process from OMMIC, which is a 100/60 nm gate-length process on Si substrate. The packaging of W-band components is traditionally based on chip-and-wire technology which provides the technical requirements but at a high cost. Significant cost reduction may be achieved with standard surface mount technologies (SMT) used at lower frequencies. Most mmW packages are different types of Quad Flat No (QFN) leads packages. In the GRACE project, a fan-out wafer level (FOWL) packaging approach offered by Fraunhofer IZM has been used.

In summary there have four primary technical objectives addressed in the GRACE project:
• Design of a 93-100 GHz Power Amplifier (PA) MMIC with an output power in the range of 500mW to 1W
• Design of a signal-source MMIC covering 93-100 GHz with state-of-the art far-carrier phase noise performance
• Development of a FOWL packaging flow for the PA MMIC
• Development of a FOWL packaging flow for the signal source MMIC

By project closure August 31, 2021 these objectives are essentially fulfilled with the demonstration of a 93-100 GHz PA with an output power of 500 mW and a signal source with state-of-the-art far carrier phase noise of -127 dBc/Hz at 10 MHz off-set from a carrier in the frequency band 93-100 GHz.

The GRACE project has received funding from the Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 821270.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The GRACE project has been run during 34 months with the aim to develop surface mount GaN HEMT radar components for EFVS systems. The project objectives have been addressed in four technical work packages (WPs) supported by a fifth WP for management.

In WP1 the radar components specifications have been iterated from a system level perspective. It was agreed that the project should aim at multiple version chips. On the one hand side highest possible performance without regards to complexity and on the other hand side good performance/complexity trade off. All project partners as well as the topic initiator have been engaged in the definition of specifications that were updated half way into the project based on performance of components in first design iteration.

In WP2 MC2 technologies has designed power amplifiers and Chalmers has designed signal source circuits, both using OMMIC's D01/006GH GaN HEMT process and design kit are that was validated sufficiently accurate within expected process variations with exception for parasitics that were compensated for. MC2 has designed four different versions of PAs and Chalmers has designed four signal source circuits based on internal or external resonators. Fraunhofer IZM has designed, modeled and simulated planar and vertical interconnects in the 93-100 GHz frequency range for the characterization of the FOWLP packaging technology applied for the fabrication of RF packages embedding both VCO and PA. Chip-package co-design was applied for the design of external resonators in the package operating at 12 GHz and 23 GHz for the VCO chip. The full packaging structures (with both PA and VCO) including RF signal path, DC supply and external resonator were designed and simulated.
In WP3 OMMIC delivered two iterations of GaN HEMT MMIC wafers in two iterations. MMICs from first and second run were sent to MC2 and Chalmers for characterization. First run MMICs were further sent to Fraunhofer IZM for packaging.

In WP4, MMICs from run 1 and 2 were characterized. First time success was met for both power amplifier and signal source MMICs. In the second MMIC run the power amplifiers were further optimized for improved gain and output power. The signal source MMICs were optimized for increased integration. VCO, xN, and frequency diviers were integrated on the same MMIC. The MMIC characterization demonstrated performance previously not available for ITAR free technology.
On-package probing demonstrated successful components.

WP5 “Project management and dissemination” has progressed according to project plan. Three scientific papers have been accepted for peer reviewed conferences and more results are to be disseminated after project closure. The project results were also disseminated at a final open workshop. No exploitation has been reported during the project period but a patent on a “COMPACT BALUN WITH OUT-OF-BAND SPURIOUS SUPPRESSION”.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The GRACE project has aimed at significantly improving performance and reducing cost of mmW radar components for next generation enhanced flight vision systems (EFVS). Critical building blocks are monolithic microwave integrated circuit (MMIC) power amplifiers and signal sources. Critical technologies are a short-gate length wide-band gap semiconductor technology, e.g. OMMIC’s D01GH or D006GH GaN HEMT technology and a suitable surface mount packaging technology, e.g. a fan-out-wafer-level (FOWL) packaging as supplied by Fraunhofer IZM.

The goals of GRACE as set out on components level, e.g. for the MMIC PA and the MMIC SS have been very competitive as compared to state of the art, for the respective functionality. On top of the high ambitions with respect to development of MMIC technology and circuit design, the GRACE project also aims at packaging the MMICs, using a fan-out-wafer-level (FOWL) packaging flow. The FOWLP is optimized to manage the thermal requirements of the PA and SS MMICs as well as the low loss required at mmW frequencies. Today, there are no standard packaging solutions available for mmW components, and certainly not for power components with high thermal constraints.

The experimental results demonstrated in the project is beyond what is previously available in Europe and ITAR free technology from other countries. In this aspect it will enable business and services that would otherwise not be possible, not only in aeronautical sector, but also in Telecom, Security and Defence applications.

Signal source MMIC

Team photo from kick-off meeting