Journal of Infrared, Millimeter, and Terahertz Waves最新文献_第2页

Development of a 40 T Fast-Cooling and Long-Pulse Magnet for a 1 THz Gyrotron 为 1 THz 陀螺仪开发 40 T 快速冷却长脉冲磁体

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-08-02 DOI: 10.1007/s10762-024-01003-x

Houxiu Xiao, Zhiyu Qiu, Xiaotao Han, Yu Huang, Shaozhe Zhang, Xianfei Chen

{"title":"Development of a 40 T Fast-Cooling and Long-Pulse Magnet for a 1 THz Gyrotron","authors":"Houxiu Xiao, Zhiyu Qiu, Xiaotao Han, Yu Huang, Shaozhe Zhang, Xianfei Chen","doi":"10.1007/s10762-024-01003-x","DOIUrl":"https://doi.org/10.1007/s10762-024-01003-x","url":null,"abstract":"The pulsed magnet can generate a high magnetic field (up to 100T), promoting the development of high-frequency high-power gyrotrons. In this article, a fast cooling and long lifetime 40 T pulsed magnet is developed for a 1 THz gyrotron. To address the various challenges in thermal and mechanical aspects, copper conductors and internal fibers have been combined to enhance mechanical strength and minimize temperature rise, prolonging the lifetime and the admissible duration of the magnet operation. Internal cooling channels are introduced to increase the cooling speed without compromising mechanical strength. Experimental results have demonstrated the magnet's reliability and repeatability in achieving a 40 T pulsed field for tens of milliseconds with a cooldown time of 6 min. It is estimated that the lifetime is about 20,000 shots at 40 T. Importantly, the magnet is capable of realizing a 40 T flat-top pulsed field (flat-top time 10 ms) with a cooldown period of 16 min. This can facilitate the long-pulsed quasi-steady operation of gyrotron operation, which is attractive for numerous high-power THz applications.","PeriodicalId":16181,"journal":{"name":"Journal of Infrared, Millimeter, and Terahertz Waves","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Compact Elliptical Slot Millimeter-Wave MIMO Antenna for 5G Applications 面向 5G 应用的紧凑型椭圆槽毫米波 MIMO 天线

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-07-25 DOI: 10.1007/s10762-024-01002-y

Nazia Farooq, Khalid Muzaffar, S. A. Malik

{"title":"Compact Elliptical Slot Millimeter-Wave MIMO Antenna for 5G Applications","authors":"Nazia Farooq, Khalid Muzaffar, S. A. Malik","doi":"10.1007/s10762-024-01002-y","DOIUrl":"https://doi.org/10.1007/s10762-024-01002-y","url":null,"abstract":"This study introduces a novel, highly compact broadband millimeter-wave (mm-wave) antenna design and its Multiple-Input-Multiple-Output (MIMO) configuration proposed for 28 GHz applications targeting 5G networks. The antenna is designed over a 0.25 mm thick Rogers RT5880LZ substrate having a relative dielectric permittivity of 2 and an overall size of 16 mm × 16 mm. Its MIMO configuration utilizes polarization diversity and includes four elliptical-slot radiators integrated with microstrip-line structures, specifically optimized for 28 GHz operation. The performance of the proposed mm-wave MIMO configuration is validated through simulation of its S-parameters using CST software and measurements obtained with a vector network analyzer (VNA). The proposed antenna demonstrates excellent S-parameter performance, achieving a gain of up to 6 dBi and a radiation efficiency of 94% across the operational frequency band. Each antenna element exhibits an impressive wide operating bandwidth of 9 GHz, spanning from 22.2 to 31.4 GHz at a − 10 dB threshold. Evaluations of the MIMO system’s performance indicate promising results, including an exceptionally low envelope correlation of about ({10}^{-5}) and a diversity gain of around 10 dB throughout the operating bandwidth. The design also ensures significant isolation between MIMO elements without requiring decoupling structures. A physical prototype of the proposed antenna is fabricated and subjected to measurements, depicting a strong corelation between the measured and simulated data, with some minor variations attributed to fabrication tolerances and cable losses. Comparative analysis further emphasizes the potential viability of the proposed MIMO antenna positioning it as a viable candidate for future compact-sized mm-wave MIMO systems.","PeriodicalId":16181,"journal":{"name":"Journal of Infrared, Millimeter, and Terahertz Waves","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141781074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ultra-Wideband PIN-PD THz Emitter with > 5.5 THz Bandwidth 带宽大于 5.5 THz 的超宽带 PIN-PD THz 发射器

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-07-24 DOI: 10.1007/s10762-024-01001-z

Milan Deumer, Simon Nellen, Sebastian Lauck, Shahram Keyvaninia, Shaffi Berrios, Matti Kieper, Martin Schell, Robert B. Kohlhaas

引用次数: 0

Terahertz Radiation from Water Molecules Rotated by Femtosecond Laser Field 飞秒激光场旋转水分子产生的太赫兹辐射

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-07-22 DOI: 10.1007/s10762-024-01000-0

Yezi Pu, Xiao-Yu Peng, Xuan Shi, Hongquan Zhao

{"title":"Terahertz Radiation from Water Molecules Rotated by Femtosecond Laser Field","authors":"Yezi Pu, Xiao-Yu Peng, Xuan Shi, Hongquan Zhao","doi":"10.1007/s10762-024-01000-0","DOIUrl":"https://doi.org/10.1007/s10762-024-01000-0","url":null,"abstract":"THz radiation can be generated routinely from water plasmas by focusing femtosecond laser pulses on a water film or water line. However, there are no relevant reports on the THz generation from rotated water molecules driven directly by strong electric field of femtosecond laser pulses under non-plasma condition. Here, we develop a theoretical model of water molecules to study the interaction between laser electric field and water molecules based on quantum mechanics theory. We find that broadband THz radiation (bandwidth ~ 10 THz) can be generated through the transitions of rotational energy levels of the rotated water molecules driven by a linear polarization mid-infrared laser (laser intensity ≤ 1012 W∙cm−2). We demonstrate that the generated THz spectrum can be controlled by changing the laser intensity and its pulse duration. Moreover, for a Gaussian pump laser beam, the high-frequency components of THz wave increase gradually, while the low-frequency components decrease gradually when the laser pulse duration increases from 150 to 400 fs. Our results provide a new idea and possibility for THz generation from water.","PeriodicalId":16181,"journal":{"name":"Journal of Infrared, Millimeter, and Terahertz Waves","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Millimeter-Wave Spectrometer for High-Precision Studies of Jet-Cooled Molecules and Weakly Bound Molecular Complexes 用于高精度研究喷射冷却分子和弱结合分子复合物的毫米波光谱仪

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-07-09 DOI: 10.1007/s10762-024-00999-6

I. V. Tarabukin, V. A. Panfilov, D. G. Poydashev, L. A. Surin

{"title":"Millimeter-Wave Spectrometer for High-Precision Studies of Jet-Cooled Molecules and Weakly Bound Molecular Complexes","authors":"I. V. Tarabukin, V. A. Panfilov, D. G. Poydashev, L. A. Surin","doi":"10.1007/s10762-024-00999-6","DOIUrl":"https://doi.org/10.1007/s10762-024-00999-6","url":null,"abstract":"We have constructed a millimeter-wave free-space absorption spectrometer for high-resolution studies of jet-cooled molecules and weakly bound van der Waals complexes. The spectrometer employs a microwave frequency generator supplemented by active frequency multipliers and covers the spectral region from 50 to 170 GHz. A nozzle source is fixed on a rooftop mirror placed in the vacuum chamber in such a way that the millimeter-wave radiation propagates parallel to the molecular jet and makes two passes along it. Such arrangement of radiation and nozzle provides better sensitivity and higher spectral resolution compared to more common perpendicular configuration. Schottky diode detectors are used to measure absorption in the molecular gas flow. The observed linewidths are 30–40 kHz, and the accuracy of the line center determination is about 3–4 kHz. The presented spectra of the astrophysically relevant rare CO isotopologues, and the weakly bound NH3–H2 complexes demonstrate the potential of the newly built spectrometer. The line splittings arising from the hyperfine interactions of the nuclear spins of 13C for CO and 14N for NH3–H2 were resolved and analyzed.","PeriodicalId":16181,"journal":{"name":"Journal of Infrared, Millimeter, and Terahertz Waves","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141576544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Broadband MIMO Configuration Using a Novel Split Ring Metasurface as Superstrate for Gain Enhancement Operating in Millimetre Wave Regime 使用新型分环金属表面作为超基底以增强毫米波频段增益的宽带多输入多输出（MIMO）配置

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-07-05 DOI: 10.1007/s10762-024-00997-8

Vijay Kumar Sahu, Rajyalakshmi Valluri, P. V. Sridevi

引用次数: 0

3D Printed Broadband Sub-terahertz Absorber for Absolute Power Sensors in Free Space 用于自由空间绝对功率传感器的 3D 打印宽带亚太赫兹吸收器

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-07-03 DOI: 10.1007/s10762-024-00996-9

Genki Kuwano, Kazuma Kurihara, Ryohei Hokari, Yuya Tojima, Moto Kinoshita

{"title":"3D Printed Broadband Sub-terahertz Absorber for Absolute Power Sensors in Free Space","authors":"Genki Kuwano, Kazuma Kurihara, Ryohei Hokari, Yuya Tojima, Moto Kinoshita","doi":"10.1007/s10762-024-00996-9","DOIUrl":"https://doi.org/10.1007/s10762-024-00996-9","url":null,"abstract":"Evaluating the output of emitters and calibrating detectors using absolute power sensors is critical for public use. In free-space thermal power sensors, the measurement accuracy and sensitivity depend on the absorption characteristics of the absorber, and the response time relates to its intrinsic thermal time constant. A response time of a few seconds is useful in practical scenarios where factors such as power variations caused by changes in the current–voltage characteristics of the emitter are monitored. At the minimum, an intrinsic thermal time constant of a few tens of second is required to achieve a few-second measurement time because the actual time can be enhanced by the control method of the sensors. However, in the sub-terahertz region, conventional broadband absorbers must be adequately thick for high absorption, increasing thermal capacity. Thus, achieving high absorption and a good thermal response remains challenging. In this study, an absorber featuring a resin-hollow pyramidal structure covered with a metal film thinner than the skin depth was devised. To realize the proposed absorber, we used resin 3D printing and Ni–P electroless plating. A comparison with conventional absorbers demonstrated that the thermal time constant was comparable to that of a planar absorber, known for its suitable response but low absorption below 1 THz, while maintaining over 98.6% absorptance in the 0.1- to 0.3-THz range. These results can aid in the construction of a sub-terahertz power sensor with high accuracy, high sensitivity, and a few-second response time.","PeriodicalId":16181,"journal":{"name":"Journal of Infrared, Millimeter, and Terahertz Waves","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Terahertz Characterization Microcellular Polyethylene Terephthalate (MCPET) across Broad Temperature Range 微孔聚对苯二甲酸乙二酯 (MCPET) 在宽温度范围内的太赫兹特性分析

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-06-25 DOI: 10.1007/s10762-024-00995-w

Hirohisa Uchida, Katsuhiko Miyamoto, Kei Takeya

引用次数: 0

Quad-port 28/38 GHz Antenna with Isolation Improvement for 5G Wireless Networks 用于 5G 无线网络的具有隔离改进功能的四端口 28/38 GHz 天线

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-06-13 DOI: 10.1007/s10762-024-00993-y

Mai. F. Ahmed, Mohamed I. Ahmed, Ahmed A. Ibrahim, S. M. Gaber

引用次数: 0

Investigation and Experiment of a Novel Chamfered V-Shaped Microstrip Slow-Wave Structure for W-Band Traveling-Wave Tube 用于 W 波段行波管的新型倒角 V 形微带慢波结构的研究与实验

IF 2.9 3区工程技术

Journal of Infrared, Millimeter, and Terahertz Waves Pub Date : 2024-06-08 DOI: 10.1007/s10762-024-00994-x

Guo Guo, Jing Zeng, Qixiang Zhao, Tianzhong Zhang, Taifu Zhou, Pengyu Lu, HanBiao Tan, Yanyu Wei

引用次数: 0