18 research outputs found

    Photonic Technologies for Millimeter- and Submillimeter-wave Signals

    Get PDF
    [EN] Fiber optic components offer a competitive implementation for applications exploiting the millimeter-wave and THz regimes due to their capability for implementing broadband, compact, and cost-effective systems. In this paper, an outline of the latest technology developments and applications of fiber-optic-based technologies for the generation, transmission, and processing of high-frequency radio signals is provided. © 2012 B. Vidal et al.B. Vidal would like to thank the Spanish Ministerio de Economia y Competitividad for its support through Project TEC2009-08078. T. Nagatsuma would like to acknowledge the financial support provided by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (A) 23246067, 2011 and the JST-ANR WITH program.Vidal Rodriguez, B.; Nagatsuma, T.; Gomes, NJ.; Darcie, TE. (2012). Photonic Technologies for Millimeter- and Submillimeter-wave Signals. Advances in Optical Technologies. 2012:1-17. doi:10.1155/2012/925065S117201

    The 2023 terahertz science and technology roadmap

    Get PDF
    Terahertz (THz) radiation encompasses a wide spectral range within the electromagnetic spectrum that extends from microwaves to the far infrared (100 GHz–∼30 THz). Within its frequency boundaries exist a broad variety of scientific disciplines that have presented, and continue to present, technical challenges to researchers. During the past 50 years, for instance, the demands of the scientific community have substantially evolved and with a need for advanced instrumentation to support radio astronomy, Earth observation, weather forecasting, security imaging, telecommunications, non-destructive device testing and much more. Furthermore, applications have required an emergence of technology from the laboratory environment to production-scale supply and in-the-field deployments ranging from harsh ground-based locations to deep space. In addressing these requirements, the research and development community has advanced related technology and bridged the transition between electronics and photonics that high frequency operation demands. The multidisciplinary nature of THz work was our stimulus for creating the 2017 THz Science and Technology Roadmap (Dhillon et al 2017 J. Phys. D: Appl. Phys. 50 043001). As one might envisage, though, there remains much to explore both scientifically and technically and the field has continued to develop and expand rapidly. It is timely, therefore, to revise our previous roadmap and in this 2023 version we both provide an update on key developments in established technical areas that have important scientific and public benefit, and highlight new and emerging areas that show particular promise. The developments that we describe thus span from fundamental scientific research, such as THz astronomy and the emergent area of THz quantum optics, to highly applied and commercially and societally impactful subjects that include 6G THz communications, medical imaging, and climate monitoring and prediction. Our Roadmap vision draws upon the expertise and perspective of multiple international specialists that together provide an overview of past developments and the likely challenges facing the field of THz science and technology in future decades. The document is written in a form that is accessible to policy makers who wish to gain an overview of the current state of the THz art, and for the non-specialist and curious who wish to understand available technology and challenges. A such, our experts deliver a 'snapshot' introduction to the current status of the field and provide suggestions for exciting future technical development directions. Ultimately, we intend the Roadmap to portray the advantages and benefits of the THz domain and to stimulate further exploration of the field in support of scientific research and commercial realisation

    The 2023 terahertz science and technology roadmap

    Get PDF
    Terahertz (THz) radiation encompasses a wide spectral range within the electromagnetic spectrum that extends from microwaves to the far infrared (100 GHz-∼30 THz). Within its frequency boundaries exist a broad variety of scientific disciplines that have presented, and continue to present, technical challenges to researchers. During the past 50 years, for instance, the demands of the scientific community have substantially evolved and with a need for advanced instrumentation to support radio astronomy, Earth observation, weather forecasting, security imaging, telecommunications, non-destructive device testing and much more. Furthermore, applications have required an emergence of technology from the laboratory environment to production-scale supply and in-the-field deployments ranging from harsh ground-based locations to deep space. In addressing these requirements, the research and development community has advanced related technology and bridged the transition between electronics and photonics that high frequency operation demands. The multidisciplinary nature of THz work was our stimulus for creating the 2017 THz Science and Technology Roadmap (Dhillon et al 2017 J. Phys. D: Appl. Phys. 50 043001). As one might envisage, though, there remains much to explore both scientifically and technically and the field has continued to develop and expand rapidly. It is timely, therefore, to revise our previous roadmap and in this 2023 version we both provide an update on key developments in established technical areas that have important scientific and public benefit, and highlight new and emerging areas that show particular promise. The developments that we describe thus span from fundamental scientific research, such as THz astronomy and the emergent area of THz quantum optics, to highly applied and commercially and societally impactful subjects that include 6G THz communications, medical imaging, and climate monitoring and prediction. Our Roadmap vision draws upon the expertise and perspective of multiple international specialists that together provide an overview of past developments and the likely challenges facing the field of THz science and technology in future decades. The document is written in a form that is accessible to policy makers who wish to gain an overview of the current state of the THz art, and for the non-specialist and curious who wish to understand available technology and challenges. A such, our experts deliver a ‘snapshot’ introduction to the current status of the field and provide suggestions for exciting future technical development directions. Ultimately, we intend the Roadmap to portray the advantages and benefits of the THz domain and to stimulate further exploration of the field in support of scientific research and commercial realisation

    The 2023 terahertz science and technology roadmap

    Get PDF
    Terahertz (THz) radiation encompasses a wide spectral range within the electromagnetic spectrum that extends from microwaves to the far infrared (100 GHz–∼30 THz). Within its frequency boundaries exist a broad variety of scientific disciplines that have presented, and continue to present, technical challenges to researchers. During the past 50 years, for instance, the demands of the scientific community have substantially evolved and with a need for advanced instrumentation to support radio astronomy, Earth observation, weather forecasting, security imaging, telecommunications, non-destructive device testing and much more. Furthermore, applications have required an emergence of technology from the laboratory environment to production-scale supply and in-the-field deployments ranging from harsh ground-based locations to deep space. In addressing these requirements, the research and development community has advanced related technology and bridged the transition between electronics and photonics that high frequency operation demands. The multidisciplinary nature of THz work was our stimulus for creating the 2017 THz Science and Technology Roadmap (Dhillon et al 2017 J. Phys. D: Appl. Phys. 50 043001). As one might envisage, though, there remains much to explore both scientifically and technically and the field has continued to develop and expand rapidly. It is timely, therefore, to revise our previous roadmap and in this 2023 version we both provide an update on key developments in established technical areas that have important scientific and public benefit, and highlight new and emerging areas that show particular promise. The developments that we describe thus span from fundamental scientific research, such as THz astronomy and the emergent area of THz quantum optics, to highly applied and commercially and societally impactful subjects that include 6G THz communications, medical imaging, and climate monitoring and prediction. Our Roadmap vision draws upon the expertise and perspective of multiple international specialists that together provide an overview of past developments and the likely challenges facing the field of THz science and technology in future decades. The document is written in a form that is accessible to policy makers who wish to gain an overview of the current state of the THz art, and for the non-specialist and curious who wish to understand available technology and challenges. A such, our experts deliver a 'snapshot' introduction to the current status of the field and provide suggestions for exciting future technical development directions. Ultimately, we intend the Roadmap to portray the advantages and benefits of the THz domain and to stimulate further exploration of the field in support of scientific research and commercial realisation

    Millimeter-Wave Band Pass Distributed Amplifier for Low-Cost Active Multi-Beam Antennas

    Get PDF
    Recently, there have been a great interest in the millimeter-wave (mmW) and terahertz (THz) bands due to the unique features they provide for various applications. For example, the mmW is not significantly affected by the atmospheric constraints and it can penetrate through clothing and other dielectric materials. Therefore, it is suitable for a vast range of imaging applications such as vision, safety, health, environmental studies, security and non-destructive testing. Millimeter-wave imaging systems have been conventionally used for high end applications implementing sophisticated and expensive technologies. Recent advancements in the silicon integrated and low loss material passive technologies have created a great opportunity to study the feasibility of low cost mmW imaging systems. However, there are several challenges to be addressed first. Examples are modeling of active and passive devices and their low performance, highly attenuated channel and poor signal to noise ratio in the mmW. The main objective of this thesis is to investigate and develop new technologies enabling cost-effective implementation of mmW and sub-mmW imaging systems. To achieve this goal, an integrated active Rotman lens architecture is proposed as an ultimate solution to combine the unique properties of a Rotman lens with the superiority of CMOS technology for fabrication of cost effective integrated mmW systems. However, due to the limited sensitivity of on-chip detectors in the mmW, a large number of high gain, wide-band and miniaturized mmW Low Noise Amplifiers (LNA) are required to implement the proposed integrated Rotman lens architecture. A unique solution presented in this thesis is the novel Band Pass Distributed Amplifier (BPDA) topology. In this new topology, by short circuiting the line terminations in a Conventional Distributed Amplifier (CDA), standing waves are created in its artificial transmission lines. Conventionally, standing waves are strongly avoided by carefully matching these lines to 50 Ω in order to prevent instability of the amplifier. This causes that a large portion of the signal be absorbed in these resistive terminations. In this thesis, it is shown that due to presence of highly lossy parasitics of CMOS transistor at the mmW the amplifier stability is inherently achieved. Moreover, by eliminating these lossy and noise terminations in the CDA, the amplifier gain is boosted and its noise figure is reduced. In addition, a considerable decrease in the number of elements enables low power realization of many amplifiers in a small chip area. Using the lumped element model of the transistor, the transfer function of a single stage BPDAs is derived and compared to its conventional counter part. A methodology to design a single stage BPDA to achieve all the design goals is presented. Using the presented design guidelines, amplifiers for different mmW frequencies have been designed, fabricated and tested. Using only 4 transistors, a 60 GHz amplifier is fabricated on a very small chip area of 0.105 mm2 by a low-cost 130 nm CMOS technology. A peak gain of 14.7 dB and a noise figure of 6 dB are measured for this fabricated amplifier. oreover, it is shown that by further circuit optimization, high gain amplification can be realized at frequencies above the cut-off frequency of the transistor. Simulations show 32 and 28 dB gain can be obtained by implementing only 6 transistors using this CMOS technology at 60 and 77 GHz. A 4-stage 85 GHz amplifier is also designed and fabricated and a measured gain of 10 dB at 82 GHz is achieved with a 3 dB bandwidth of 11 GHz from 80 to 91 GHz. A good agreement between the simulated and measured results verifies the accuracy of the design procedure. In addition, a multi-stage wide-band BPDA has been designed to show the ability of the proposed topology for design of wide band mmW amplifiers using the CMOS technology. Simulated gain of 20.5 dB with a considerable 3 dB bandwidth of 38 GHz from 30 to 68 GHz is achieved while the noise figure is less than 6 dB in the whole bandwidth. An amplifier figure of merit is defined in terms of gain, noise figure, chip area, band width and power consumption. The results are compared to those of the state of the art to demonstrate the advantages of the proposed circuit topology and presented design techniques. Finally, a Rotman lens is designed and optimized by choosing a very small Focal Lens Ratio (FL), and a high measured efficiency of greater than 30% is achieved while the lens dimensions are less than 6 mm. The lens is designed and implemented using a low cost Alumina substrate and conventional microstrip lines to ease its integration with the active parts of the system.1 yea

    Terahertz Technology and Its Applications

    Get PDF
    The Terahertz frequency range (0.1 – 10)THz has demonstrated to provide many opportunities in prominent research fields such as high-speed communications, biomedicine, sensing, and imaging. This spectral range, lying between electronics and photonics, has been historically known as “terahertz gap” because of the lack of experimental as well as fabrication technologies. However, many efforts are now being carried out worldwide in order improve technology working at this frequency range. This book represents a mechanism to highlight some of the work being done within this range of the electromagnetic spectrum. The topics covered include non-destructive testing, teraherz imaging and sensing, among others

    State-of-the-Art of High-Power Gyro-Devices - Update of Experimental Results 2023 (KIT Scientific Reports ; 7765)

    Get PDF
    This report presents an update of the experimental achievements published in the review “State- of-the-Art of High-Power Gyro-Devices and Free Electron Masers”, Journal of Infrared, Millimeter, and Terahertz Waves, 41, No. 1, pp 1-140 (2020) and in the KIT Scientific Report 7761 (2021), related to the development of gyro-devices (Tables 2-34). Emphasis is on high-power gyrotron oscillators for long-pulse or continuous wave (CW) operation and pulsed gyrotrons for any applications

    State-of-the-Art of High-Power Gyro-Devices

    Get PDF
    This report presents an update of the experimental achievements published in the review “State- of-the-Art of High-Power Gyro-Devices and Free Electron Masers”, Journal of Infrared, Millimeter, and Terahertz Waves, 41, No. 1, pp 1-140 (2020) and in the KIT Scientific Report 7761 (2021), related to the development of gyro-devices (Tables 2-34). Emphasis is on high-power gyrotron oscillators for long-pulse or continuous wave (CW) operation and pulsed gyrotrons for any applications

    New photonic architectures and devices for generation and detection of sub-THz and THz waves

    Get PDF
    The development of high-quality and reliable devices in the THz frequency region to fill the existing technological gap has become a major concern. This is chiefly motivated by the need of a widespread exploitation of the extensive variety of identified applications in this frequency region by a wide range of users, including the non-scientific community. The photonic approaches used for these purposes offer important and exclusive advantages over other existing alternatives, which have as a main representative the all-electronic technology, especially in terms of frequency range coverage, possibility of photonic distribution using optical fibers, weight and Electromagnetic Interference (EMI) immunity. Nevertheless, the optical techniques have traditionally provided with worse performance in terms of phase noise, tunability and dynamic range (in generation), and conversion ratio (in detection) when compared to state-of-theart all-electronic THz technology. The work accomplished in this thesis focuses on the design, development and validation of new photonic architectures and devices for both generation and detection of sub-THz and THz waves which overcome the drawbacks of optical techniques at this frequency region while maintaining all their advantages. In this thesis, several photonic sub-THz and THz generation systems have been developed using Difference Frequency Generation (DFG) architectures in which the DFG source is provided by an Optical Frequency Comb Generator (OFCG) and optical mode selection. Different devices and techniques are investigated for each part of the system before arriving to the final high performance synthesizer. Passively Mode-Locked Laser Diodes (PMMLDs) are firstly evaluated as integrated OFCG. An improved design of the OFCG is achieved with a scheme based on a Discrete Mode (DM) laser under Gain- Switching (GS) regime and optical span expansion by the use of a single Electro- Optical (EO) phase modulator. As optical mode selection, both high selective optical filtering and Optical Injection Locking (OIL) are used and evaluated. A commercial 50 GHz photodiode (PD) and an n-i-pn-i-p superlattice THz photomixer are employed as photodetector for Optical to THz conversion. The final reported system consists on an OFCG based on GS, OIL as mode selection strategy and an n-i-pn-i-p superlattice photomixer. This synthesizer offers a wide frequency range (60-140 GHz), readily scalable to a range between 10 GHz and values well above 1 THz. Quasi-continuous tunability is offered in the whole frequency range, with a frequency resolution of 0.1 Hz at 100 GHz that can be straightforwardly improved to 0.01 Hz at 100 GHz and 0.1 Hz at 1 THz. The measured FWHM at 120 GHz is <10 Hz, only limited by the measurement instrumentation. The system offers excellent frequency and power stability with frequency and power deviations over 1 hour of 5 Hz and 1.5 dB, respectively. These values are also limited by both the accuracy and uncertainty of the measurement setup. The performance achieved by this photonic sub-THz and THz synthesizer for most figures of merit matches or even surpasses those of commercial stateof- the-art all-electronic systems, and overcomes some of their characteristics in more than one million times when compared to commercial state-of-the-art photonic solutions. The detection part of this thesis explores the use of photonic architectures based on EO heterodyne receivers and the key devices that encompass these architectures: photonic Local Oscillators (LOs) and EO mixers. First results are developed at microwave frequencies (<15 GHz) using an Ultra-Nonlinear Semiconductor Amplifier (XN-SOA) as EO mixer and a GS based photonic LO. It is demonstrated how this LO device based on GS provides with a significant improvement in the performance of the overall EO receiver when compared to a traditional linearly modulated LO. Furthermore, this detection architecture is validated in an actual application (photonic imaging array), featuring scalability, flexibility and reasonable conversion ratios. After this, an EO heterodyne receiver is demonstrated up to frequencies of 110 GHz. The photonic LO employed is the abovementioned photonic sub- THz synthesizer developed in this thesis, while the EO mixer is an np-i-pn quasi ballistic THz detector. The first fabricated sample of this novel device is used, which is optimized for homodyne/heterodyne detection. The resulting sub-THz EO heterodyne receiver has conversion ratios around -75 dB. It works under zero-bias conditions, which together with the photonic distribution of the LO offers a high potential for remote detection of sub-THz and THz waves. In summary, new photonic architectures and devices are able to provide with state-of-the-art performance for generation of sub-THz and THz waves. In the case of EO heterodyne detection at sub-THz and THz frequency regions, photonic techniques are improving their performance and are closer to offer an alternative to all-electronic detectors. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------El desarrollo de dispositivos fiables y de alta calidad en el rango frecuencial de Terahercios (THz) con el fin de cubrir el actual vacío tecnológico se ha convertido en una importante inquietud científica. Esto está principalmente motivado por la necesidad de explotar el gran número de aplicaciones identificadas en esta región frecuencial por un gran número de usuarios, incluyendo a usuarios no científicos. El enfoque fotónico empleado para estos propósitos ofrece importantes y exclusivas ventajas sobre otras alternativas existentes, que tienen como principal representante a la tecnología electrónica, especialmente en términos de rango de frecuencia de funcionamiento, posibilidad de distribución fotónica con fibras ópticas, peso, e inmunidad electromagnética. No obstante, las técnicas fotónicas tradicionalmente han ofrecido peores prestaciones en términos de ruido de fase, sintonía y rango dinámico (en generación) y ratio de conversión (en detección) con respecto a la tecnología electrónica de THz en el estado del arte. El trabajo realizado en esta tesis se centra en el diseño, desarrollo y validación de nuevas arquitecturas y componentes fotónicos tanto para generación como detección de ondas de sub-THz y THz que permitan solucionar las desventajas de las técnicas ópticas manteniendo todas sus ventajas. En esta tesis, varios sistemas de generación de sub-THz y THz han sido desarrollados utilizando arquitecturas Difference Frequency Generation (DFG) en las que la fuente DFG es proveída por un Optical Frequency Comb Generator (OFCG) y selección de modos ópticos. Diferentes dispositivos y técnicas son investigados para cada parte del sistema hasta conseguir un sintetizador de altas prestaciones. Passively Mode-Locked Laser Diodes (PMMLDs) son inicialmente evaluados como OFCG integrados. Un diseño mejorado del OFCG es conseguido mediante el uso de un esquema basado en un láser Discrete Mode (DM) bajo régimen Gain Switching (GS) y expansión del ancho de banda óptico mediante el uso de un modulador de fase Electro-Óptico (EO). Como estrategia de selección de modos ópticos, tanto filtrado óptico altamente selectivo como Optical Injection Locking (OIL) son usados y evaluados. Un fotodiodo comercial de ancho de banda 50 GHz y un fotomezclador de THz de superred n-i-pn-i-p son empleados. El sistema de generación final que se presenta en esta tesis consiste en un OFCG basado en GS, OIL como técnica de selección de modos ópticos y un fotomezclador de THz de superred n-i-pn-i-p. Este sintetizador ofrece un rango de funcionamiento de 60 a 140 GHz, directamente escalable a un rango entre 10 GHz y valores más allá de un THz. Sintonía cuasi-continua es ofrecida en todo el rango de frecuencia de operación, con una resolución en frecuencia de 0.1 Hz a 100 GHz que puede ser directamente escalable a 0.01 Hz a 100 GHz y 0.1 Hz a 1 THz. El ancho de línea a 3-dB de la señal a 120 GHz es menor de 10 Hz, solo limitada por la instrumentación de medida. El sistema ofrece una excelente estabilidad en potencia y frecuencia, con desviaciones sobre una hora de operación de 1.5 dB y 5 Hz, respectivamente. Estos valores también están limitados por la precisión e incertidumbre de la instrumentación de medida. Las prestaciones conseguidas por este sintetizador fotónico de sub-THz y THz para la mayoría de figuras de mérito, igualan o superan aquellas de las mejores soluciones comerciales electrónicas en el estado del arte, y supera algunas de estas características en más de un millón de veces en el caso de soluciones fotónicas comerciales en el estado del arte. La parte de detección de esta tesis explora el uso de arquitecturas fotónicas basadas en receptores EO heterodinos y los componentes clave que forman estas arquitecturas: Oscilador Local (OL) fotónico y mezcladores EO. Los primeros resultados son desarrollados en el entorno de microondas (<15 GHz) usando un amplificador de semiconductor óptico ultra no lineal (XN-SOA) como mezclador EO y un OL fotónico basado en GS. Se demuestra como este OL basado en GS ofrece una mejora significativa de las prestaciones del receptor con respecto al uso de OL fotónicos tradicionales basados en modulación lineal. Además, esta arquitectura de detección es validada en una aplicación real (imaging array fotónico), ofreciendo escalabilidad, flexibilidad y ratios de conversión razonables. Tras esto, un receptor EO heterodino es demostrado hasta frecuencias de 110 GHz. El OL fotónico empleado es el sintetizador de altas prestaciones presentado en esta tesis, mientras que el mezclador EO es un nuevo detector de THz: el np-i-pn cuasi-balístico. La primera muestra fabricada de estos nuevos dispositivos, especialmente diseñados y optimizados para detección homodina y heterodina, es empleada. El receptor EO heterodino resultante ofrece ratios de conversión de -75 dB. Este dispositivo es capaz de trabajar sin alimentación, lo que unido a la distribución fotónica del OL, ofrece un gran potencial para detección remota de ondas de sub-THz y THz. En resumen, las nuevas arquitecturas y dispositivos fotónicos presentados en esta tesis son capaces de ofrecer prestaciones en el estado del arte para generación de ondas de sub-THz y THz. En el caso de detectores EO heterodinos en frecuencias de sub-THz y THz, las técnicas fotónicas están mejorando sus prestaciones significativamente y están cada vez más cerca de ofrecer una alternativa a detectores electrónicos en el estado del arte

    `THz Torch' technology: secure thermal infrared wireless communications using engineered blackbody radiation

    No full text
    The thermal (emitted) infrared frequency bands, from 20 to 40 THz and 60 to 100 THz, are best known for applications in thermography. This underused and unregulated part of the spectral range offers opportunities for the development of secure communications. The `THz Torch' concept, operating between the THz and mid-infrared ranges, was recently introduced. This technology fundamentally exploits engineered blackbody radiation, by partitioning thermally-generated spectral power into pre-defined frequency channels; the energy in each channel is then independently pulsed modulated to create a robust form of short-range secure communications in the far/mid-infrared. In the thesis, the development of `THz Torch' wireless communications systems will first be introduced. State-of-the-art THz technologies, infrared sources and detectors, as well as near-infrared and visible light communications technologies, will be reviewed in Chapter 2. Basic single-channel architecture of the `THz Torch' technology will be presented in Chapter 3. Fundamental limits for the first single-channel proof-of-concept demonstrator will be discussed, and possible engineering solutions will be proposed and verified experimentally. With such improvements, to date, octave bandwidth (25 to 50 THz) single-channel wireless links have been demonstrated with >2 kbit/s data rate and >10 cm transmission distance. To further increase the overall end-to-end data rate and/or the level of security, multiplexing schemes for `THz Torch' technologies are proposed in Chapter 4. Both frequency division multiplexing (FDM) and frequency-hopping spread-spectrum (FHSS) working demonstrators, operating between 10 and 100 THz spectral range, will be implemented. With such 4-channel multiplexing schemes, measured bit error rates (BERs) of <10−6 have been achieved over a transmission distance of 2.5 cm. Moreover, the integrity of such 4-channel multiplexing system is evaluated by introducing four jamming, interception and channel crosstalk experiments. Chapter 5 gives a detailed power link budget analysis for the 4-channel multiplexing system. The design, simulation and measurement of scalable THz metal mesh filters, which have potential applications for multi-channel `THz Torch' technology, will be presented in Chapter 6. The conclusions and further work are summarised in the last chapter. It is expected that this thermodynamics-based approach represents a new paradigm in the sense that 19th century physics can be exploited with 20th century multiplexing concepts for low cost 21st century ubiquitous security and defence applications in the thermal infrared range.Open Acces
    corecore