W-band project for better data transmission in satellite comms

In order to meet the world’s rapidly growing data consumption and increasing bandwidth requirements, satellite communications are shifting to higher frequencies. The W-band (75–110 GHz) is well suited for use in space, but technical components have been lacking so far. In response to this, the Fraunhofer Institute for Applied Solid State Physics IAF has launched the BEACON project.

Not only does the W-band offer high data throughput when used at high altitudes and in space, it is also likely to significantly increase system capacity, reduce the number of gateway earth stations and reduce overall system costs. However, there has been a lack of suitable technology and hardware for applications in the W-band frequency range to date. Fraunhofer IAF, together with RPG-Radiometer Physics, is addressing this challenge with the project ‘BEACON — W-band Integrated Active Receive Front-End’.

The project partners are developing an integrated active W-band receive front-end with an operating frequency of 81 to 86 GHz that will enable extremely high data rates or long-distance data transmission with low power consumption. The receive module is based on Fraunhofer IAF’s extremely low-noise MMIC (monolithic microwave integrated circuit) technology.

“Fraunhofer IAF has done tremendous development work in the mHEMT process over the past years and has acquired a core competence in developing amplifiers with the lowest noise worldwide. Based on this, the project aims to reduce the noise figure to below 3.5 dB and thus significantly improve the state of the art,” said Dr Philipp Neininger, project coordinator at Fraunhofer IAF. In addition, the receive module is designed to isolate left- from right-hand circular polarisation and amplify them with two separate channels (LHCP and RHCP), which serves to effectively double data throughput.

A major challenge in the BEACON project is the novel arrangement of components on the very small module area. The new approach involves integrating a large number of functions within a very small footprint: these include the polariser, waveguide transitions to two individual amplifiers, two coaxial output connectors and the associated DC circuitry.

“The combination of these features — extremely low noise, two different polarisations and an innovative array — brings an enormous technological advance in the field of W-band components,” Neininger said.

In 2021, satellite signals in the W-band frequency range were received from space for the first time. The W-Cube nanosatellite also began its journey to polar orbit aboard a Falcon 9 rocket and has since been successfully transmitting satellite signals to Earth at 75 GHz from an altitude of 500 km. For this mission, Fraunhofer IAF had already developed the transmitter module of the satellite as well as the receive module of the corresponding ground station.

Image caption: Close-up of a similar receive module showing the integration of different components. Image ©Fraunhofer IAF