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StatusOngoing
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Status date2025-07-14
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Activity Code5C.432
In this activity, a W-band integrated active receive front-end module at an operating frequency of 81 to 86 GHz was investigated. The module is based on Fraunhofer IAF’s ultra low-noise 50-nm metamorphic High Electron Mobility Transistors (mHEMTs) Monolithic Microwave Integrated Circuits (MMIC) technology. It doubles the channel capacity by separating and amplifying both the Left-Hand Circular Polarization (LHCP) and Right-Hand Circular Polarization (RHCP) components. At the same time, the project targets a significant reduction in noise figure performance as compared to previous W-Band Low Noise Amplifier (LNA) modules.
To that end, this activity covers both the design of novel low-noise amplifiers as well as their seamless integration in a frontend module that features a square or circular waveguide as input and a coaxial output connector for each polarization. One important aspect of the project is the lateral size requirement of less than 3λ for the entire module, which includes all RF components as well as the biasing circuitry. To separate the two incoming polarizations, several novel and ultra-compact polarizer implementations were considered in terms of their size, insertion loss and manufacturability. Furthermore, the project also targets a significant improvement of the noise figure to below 3.5 dB, while maintaining a gain value in excess of 30 dB. Also, the project team investigated ways to implement compact and high-performance out-of-band rejection filters, such that signals below the frequency range of interest are attenuated significantly.
More specifically, the MMIC investigation targets an amplifier that simultaneously features high gain and input return loss, an excellent noise figure and compactness.
The module on the other hand must exhibit a maximum footprint of 3λ (10.8 mm) in both dimensions of the antenna. Within this space, a multitude of functions must be realized: this includes the polarizer, waveguide transitions to two individual amplifiers, two coaxial output connectors and associated DC bias circuitry.
The receive front-end (RFE) enables extremely high data rates or low-power data transmission over a large distance. Its small size allows for its application in 2D array configurations with two separate channels for left-hand and right-hand circular polarisations.
The targeted receive front-end integrates two individual ultra low-noise amplifiers, a high-performance polarizer, a transmit rejection filter, miniature coaxial connectors and associated bias circuitry within a very compact form factor.
The W-band receive-front end consists of a waveguide input that supports LHCP/RHCP modes (square waveguide). The input signal feeds a polarizer, after which the signal is routed to two separate low-noise amplifier MMICs. A transmit rejection filter attenuates unwanted signals from the transmit path. The two amplified signals are then routed to coaxial output connectors. A DC biasing system provides accurate gate and drain voltages for each of the amplifier’s stages.
In the first work package, an overview of suitable semiconductor technologies and components is compiled. A baseline architecture and a verification plan are developed. Work package 2 entails design and processing of the critical components. In the third work package, a preliminary design baseline is established. WP four contains the development of implementation, test and verification plans. A second iteration of design, manufacturing and assessment of the required elements is allocated in work package 5. This work package also entails assembly and full characterization of the complete module. In WP6, the results are evaluated and a roadmap is laid out for commercialisation.
The project has been successfully completed.
