Sub-THz traveling wave amplifiers based on the double corrugated waveguide

Email Print Request Permissions Summary form only given. The importance of the sub-THz (0.1-1 THz) portion of the spectrum is recognized fundamental for many applications. In particular, the region around 0.22 THz is suitable for high data rate communications1 and imaging due the low atmospheric attenuation window. However, high power is needed in this frequency range to provide a reasonable length of the transmission path. Vacuum electron devices represent so far the only viable solution for relatively output power at those frequencies. Wideband Traveling Wave Tube Amplifiers (TWTAs) operating in the 0.22 THz range were demonstrated with relevant performance2. The high cost of TWTAs still prevents their wide market diffusion. The double corrugated waveguide (DCW) is a slow wave structure of easy fabrication and assembly. A TWT based on the DCW is presented as possible affordable approach3. A relative high output power (3.7W) over a wide bandwidth (20 GHz) centered at 0.23THz was demonstrated, with 13kV beam voltage and 30mA beam current. The wideband performance is related to the superposition of the beam line with the dispersion curve over a wide frequency region. The optimization of the DCW dimensions is then a crucial step to assure wideband amplification. A study on the definition of the widest synchronism region is proposed. The aim is to extend the region included between the lower and upper cutoff frequencies of the dispersion curve and to control the its slope, maintaining a low beam voltage and suitable values of interaction impedance and losses

Photonic band gap corrugated slow wave structure for THz sheet-beam vacuum electron devices

The use of photonic band gap (PBG) technology is investigated to alleviate some of the typical issues of vacuum electron devices at terahertz and is shown as particularly suitable for the use of large sheet beams. A full interaction structure including the slow wave structure and the coupler based on a tapered PBG corrugated waveguide is proposed for sheet beam backward wave oscillators (BWO). The case of a 346 GHz BWO is considered

Photonic crystal-coupler for sheet beam THz vacuum electron tubes

Photonic Crystal (PhC) technology was recently proposed as a compact and effective solution to improve the performance and ease the fabrication of terahertz vacuum electron devices. In particular, the introduction of defects in a bi-dimensional, all metallic PhC provides very effective transmission of the useful signal in a compact input/output coupler where a novel tunnel for sheet-beam injection/collection is realized. Simulation results are here experimentally validated via measurements on a Ku-band scaled model of the PhC-coupler which confirm the validity of the concept

A Fast Model of a 1-D Nonlinear Beam-Wave Interaction for a 225GHz TWT

A code for a fast 1-dimensional model has been developed for the simulation for the beam-wave interaction in the travelling wave tube amplifier (TWTA). the code is based on a Lagrangian algorithm. The input parameters are modified to extend the code validity to structure different from angular symmetric structures. The output power and gain for the double corrugated waveguide (DCW) TWT at 225 GHz is compared with particle in cell (PIC) simulators

Ultra Capacity Wireless Layer Beyond 100 GHz Based on Millimeter Wave Traveling Wave Tubes

The exploitation of the millimeter wave spectrum (100 – 300 GHz) for wireless communications needs a breakthrough in transmission power. Multigigabit per second data rate can be transported by the wide frequency bands available in the millimeter wave spectrum. The high atmosphere attenuation and the lack of solid state amplifiers with adequate power have so far prevented to achieve long transmission range. The new European Commission Horizon 2020 ULTRAWAVE, “Ultracapacity wireless layer beyond 100 GHz based on millimeter wave traveling wave tubes” is devoted to produce the millimeter wave technology for enabling a mesh of Point to multiPoint high capacity layers at D-band (141 – 148.5 GHz) connected by G-band Point to Point links (275 – 305 GHz) to the fiber access poin

Sub-THz wireless transport layer for ubiquitous high data rate

5G and the future 6G ambitions will be real when wireless “unlimited data’ will be available. Multi-Gigabit per second or Terabit per second are the new units to measure the data demand of emerging applications such as 8K video, e-health, extended reality, vehicle to everything , and many others. Actual wireless networks are based on the fiber substrate that feeds, by fixed access points, a wireless layer for distribution to users at much lower capacity, posing a limit to the introduction of data hungry applications. To increase the area capacity of the wireless distribution layer, an ubiquitous data source is needed. A wireless layer to transport data at rooftop level is conceived to replicate wireless the data provision of the fiber substrate, with unlimited access flexibility. This new layer is fed by fiber and provides to the wireless distribution layer links arbitrarily distributed, for a ubiquitous data distribution. The architecture and enabling technology of the proposed wireless transport layer will be described

Point to Multipoint at Millimetre Waves Above 90 GHz

The Point to multipoint wireless distribution is the most effective and affordable modality to deliver data to a high number of terminals distributed randomly in a wide area. The use of high density small cells, mandatory to increase the throughput per users, maintaining terminals at sub-6 GHz frequency, needs capillary backhaul networks that fibers cannot effectively provide. The TWEETHER project for point to multipoint at W-band is opening the route to a new generation of millimeter wave wireless networks for an affordable and easy to deploy backhaul and access with high capacity. The perspectives offered by the full millimeter wave spectrum provide a solution to the increasing data rate request

Guest Editorial Special Issue on Vacuum Electronic Devices, From Mega to Nano:Beyond One Century of Vacuum Electronics

I am delighted and honored to open the sixth Special Issue on Vacuum Electronics published by IEEE TRANSACTIONS ON ELECTRON DEVICES (T-ED) “From Mega to Nano: Beyond One Century of Vacuum Electronics” following the successful Special Issues published in January 2001, May 2005, May 2009, June 2014, and June 2018

one6G white paper, 6G technology overview:Second Edition, November 2022

6G is supposed to address the demands for consumption of mobile networking services in 2030 and beyond. These are characterized by a variety of diverse, often conflicting requirements, from technical ones such as extremely high data rates, unprecedented scale of communicating devices, high coverage, low communicating latency, flexibility of extension, etc., to non-technical ones such as enabling sustainable growth of the society as a whole, e.g., through energy efficiency of deployed networks. On the one hand, 6G is expected to fulfil all these individual requirements, extending thus the limits set by the previous generations of mobile networks (e.g., ten times lower latencies, or hundred times higher data rates than in 5G). On the other hand, 6G should also enable use cases characterized by combinations of these requirements never seen before, e.g., both extremely high data rates and extremely low communication latency). In this white paper, we give an overview of the key enabling technologies that constitute the pillars for the evolution towards 6G. They include: terahertz frequencies (Section 1), 6G radio access (Section 2), next generation MIMO (Section 3), integrated sensing and communication (Section 4), distributed and federated artificial intelligence (Section 5), intelligent user plane (Section 6) and flexible programmable infrastructures (Section 7). For each enabling technology, we first give the background on how and why the technology is relevant to 6G, backed up by a number of relevant use cases. After that, we describe the technology in detail, outline the key problems and difficulties, and give a comprehensive overview of the state of the art in that technology. 6G is, however, not limited to these seven technologies. They merely present our current understanding of the technological environment in which 6G is being born. Future versions of this white paper may include other relevant technologies too, as well as discuss how these technologies can be glued together in a coherent system

Efficient interference mitigation in mmWave backhaul network for high data rate 5G wireless communications

This paper investigates the performance of the W band millimeter wave (mmWave) backhaul network proposed by our EU TWEETHER project. We focus on the downlink transmission of the mmWave backhaul network, in which each of the hubs serves a cluster of base stations (BSs). In the considered backhaul network, available frequency resources are first allocated to the downlink links with the consideration of fairness issue. In order to mitigate interference in the mmWave backhaul network, each hub operates the proposed algorithm, namely cooperation and power adaptation (CPA). Our simulation results show that, the backhaul network with mmWave capabilities can achieve a significant better throughput performance than the sub-6 GHz ultra high frequency (UHF) backhaul network. Furthermore, our simulations also reveal that the proposed CPA algorithm can efficiently combat interference in the backhaul network