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Ultra capacity wireless layer beyond 100 GHz based on millimeter wave Traveling Wave Tubes

Periodic Reporting for period 2 - ULTRAWAVE (Ultra capacity wireless layer beyond 100 GHz based on millimeter wave Traveling Wave Tubes)

Reporting period: 2018-09-01 to 2021-05-31

For the first time, smartphones and tablets data usage exceeds desktops. This is a wake up call for manufacturers and operators to provide users with ubiquitous, high speed and high quality wireless coverage. The 5G cell densification is the only available route due to the constraints of sub-6GHz networks. A dense deployment of small cells requires a capillary backhaul and novel approaches to fronthaul. While the increase of data rate at small cell level has found solutions, the quest for high-density backhaul remains still unanswered. The fiber is too expensive and of difficult deployment. The wireless backhaul is the preferred solution for operators for performance, flexibility and cost. The traffic demand requires an upshift from microwave to high capacity millimeter wave backhaul, and overcome the current technology limits. ULTRAWAVE responds to the challenge of high capacity, high cell density backhaul by proposing, for the first time, the exploitation of the whole millimeter wave spectrum beyond 100 GHz. This will be used to create an ultra capacity layer providing more than 100 Gbps per kilometer square in Point to Multi point at D-band (141 – 174.8 GHz) over 500 m radius of coverage, fed by novel G-band (300 GHz) Point to Point high capacity links with more than 600 m range. The ULTRAWAVE system is empowered by the convergence of three main technologies: vacuum electronics, solid-state electronics and photonics in a unique wireless system, with transmission power at Watt level at millimeter waves, generated by novel traveling wave tubes. The ULTRAWAVE consortium includes five top Academic institutions and three high technology SMEs from five European countries. The vast capacity, flexibility and easy deployment of the ULTRAWAVE layer will enable backhaul of hundreds of small and pico cells, no matter the density, and will open scenarios so far not conceivable for new networks paradigms and architectures aiming at a full 5G implementation.
The ULTRAWAVE D-band (141 – 148.5 GHz) point to multipoint wireless system consists of a network of Transmission Hubs to produce wide sector area coverage and compact Network Terminal Equipment units (terminals) to be deployed arbitrarily in the coverage area. The transmission hubs are connected to the fiber and interconnected between them by G-band (275 -305 GHz) ultrahigh capacity links. Both D-band transmission hubs and terminals use simple radio topology. This is an important design aspect for the economy of the system, since the electronics at D-band is very challenging, not only in terms of MMMICs (millimeter wave Monolithic Integrated Circuits) but also interconnections, transitions, assembly.
Two novel high power Traveling Wave Tube (TWT) amplifiers, one at D-band and one at G-band, has been designed and are in final fabrication phase, to provide transmission power to satisfy the link budget in their respective bands of operation.
A novel D-band MMMIC (millimeter waves monolithic integrated circuit) chip set, antennas, housing, mother board, filters were designed, built and tested.
The G-band point to point system presented a formidable technology challenge due to the short wavelength. A proof of concept configuration has been developed. A G-band transmitter includes a photonics transmitter to produce the modulated signal, a MMIC power amplifier as driver of a G-band TWT, to produce the required transmission power, connected to a high gain antenna. The receiver includes an antenna connected to a new generation Low Noise Amplifier and a downconverter at D-band.
The novelty in combining TWTs of new design with advanced transceiver at D-band and G-band is a progress beyond the state of the art.
The advances in D-band and G-band technology introduced by the ULTRAWAVE project will boost the European sub-THz industry and independence, speeding up the deployment of innovative products suitable not only for the wireless economy sector, but also for other telecommunication systems or applications such as high resolution radar and imaging.
The ULTRAWAVE consortium was aware from the beginning of the formidable challenge and the arduous technology travel in an unexplored territory. Most of the partners mutually established a close working and personal relationship during the H2020 TWEETHER project, making the ULTRAWAVE team an integrated research unit.
The ULTRAWAVE project has developed new technological approaches, discovered obstacles and the solutions to solve them, established fundamental processes and paved the way for the European independence in sub-THz electronics, born for wireless network, but enabling for a broad range of applications.

The present and future impact of ULTRAWAVE is:

European MMMIC chip set at D-band with performance at the state of the art.

Fabrication processes and facilities for sub-THz TWTs.

Integration and assembly process for sub-THz components up to 300 GHz.

Novel wireless network architectures and networking performance strategy for economy and deployment.

Development of the full radio chain from C-band modem to D-band transmitter.
Coverage rendering D-band PmP