IEEE Transactions on Terahertz Science and Technology最新文献

{"title":"Perturbed Resonance Frequency Analysis for Imaging Epidermal Thickness and Water Content Using Terahertz Spectroscopy","authors":"Pouyan Rezapoor;Aleksi Tamminen;Juha Ala-Laurinaho;Dan Ruan;Zachary Taylor","doi":"10.1109/TTHZ.2025.3637149","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3637149","url":null,"abstract":"In this study, we propose a novel perturbed resonance frequency analysis method where the modified, THz frequency, Fabry–Pérot resonances of a tissue loaded quartz window are used to quantify superficial skin layer thickness and water content. The superficial layer is treated as an unknown matching layer between the quartz window and deep epidermis and resolution of the longitudinal modes provides a unique mapping from resonance frequency and width to layer water content and thickness. The approach is experimentally validated with a telecentric beam scanning system coupled to VNA extender operating in the 330–500 GHz band. The system is used to observe the dynamic effects of stinging nettle exposure on in vivo human skin over a 52 × 52 mm² field-of-view. Spectroscopic imaging revealed an immediate decrease in resonance frequency and width of up to 15 GHz and 20 GHz, respectively, compared to unperturbed skin, which maps to a 30 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m increase in thickness and 25% decrease in water content. This immediate response was followed by a gradual recovery to pre-exposed values. These findings demonstrate additional dielectric window utility in terahertz biomedical spectroscopy in imaging beyond the standard field flattening and system calibration roles.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 4","pages":"357-365"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11268937","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147606240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving Terahertz-Detection Sensitivity of $8 times 8$ FET Arrays Through Liquid-Nitrogen Cooling in a Compact Low-Noise Cryostat","authors":"Jakob Holstein;Nicholas K. North;Arne Hof;Sanchit Kondawar;Dmytro B. But;Mohammed Salih;Lianhe Li;Edmund H. Linfield;A. Giles Davies;Joshua R. Freeman;Alexander Valavanis;Alvydas Lisauskas;Hartmut G. Roskos","doi":"10.1109/TTHZ.2026.3665013","DOIUrl":"https://doi.org/10.1109/TTHZ.2026.3665013","url":null,"abstract":"We show that the sensitivity of antenna-coupled field-effect transistors (FETs) to terahertz (THz) radiation improves continuously with decreasing temperature. The noise-equivalent power (NEP) of 540 GHz patch-antenna-coupled FETs decreases as temperature reduces to <inline-formula><tex-math>$20 ,{mathrm{K}}$</tex-math></inline-formula>. We project NEP values approaching 1–2pW/<inline-formula><tex-math>$sqrt{mathrm{Hz}}$</tex-math></inline-formula> under efficient power coupling conditions (e.g., using a superstrate Si-lens), which is comparable to superconducting niobium transition-edge sensorsat <inline-formula><tex-math>$4 ,{mathrm{K}}$</tex-math></inline-formula>. Building on these findings, a compact, low-noise, liquid-nitrogen-cooled (<inline-formula><tex-math>$77 ,{mathrm{K}}$</tex-math></inline-formula>) FET-based direct (incoherent) THz-power sensing system for spectroscopy applications was realized. Here, an 8×8 pixel-binned detector array fabricated in a commercial 65-nm Si-CMOS process, was optimized for operation in the 2.85–<inline-formula><tex-math>$3.4 ,mathrm{THz}$</tex-math></inline-formula> band. Characterization was performed in the focal plane of a 2.85-THz quantum-cascade laser delivering <inline-formula><tex-math>$sim$</tex-math></inline-formula>2 mW of THz power. A linear dynamic range exceeding <inline-formula><tex-math>$67 ,{mathrm{dB}}$</tex-math></inline-formula> was achieved without saturation (for 1 Hz-detection bandwidth). The system provides a <inline-formula><tex-math>$-3 ,{mathrm{dB}}$</tex-math></inline-formula> readout bandwidth of <inline-formula><tex-math>$5 ,{mathrm{MHz}}$</tex-math></inline-formula>, exceeding that of conventional thermal detectors (typically <inline-formula><tex-math>$1 ,{mathrm{kHz}}$</tex-math></inline-formula>). Combined with its broad temperature operability (20–<inline-formula><tex-math>$300 ,mathrm{K}$</tex-math></inline-formula>) and compact design, the system is particularly well suited for space- and payload-constrained platforms such as balloon- and satellite-based missions, where deep cryogenic coolingis impractical.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 4","pages":"463-475"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147606333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Create Change: IEEE","authors":"","doi":"10.1109/TTHZ.2026.3684285","DOIUrl":"https://doi.org/10.1109/TTHZ.2026.3684285","url":null,"abstract":"","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 5","pages":"620-620"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11494160","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147734757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IEEE Microwave Theory and Techniques Society Information","authors":"","doi":"10.1109/TTHZ.2026.3682165","DOIUrl":"https://doi.org/10.1109/TTHZ.2026.3682165","url":null,"abstract":"","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 5","pages":"C2-C2"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11494159","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147734754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Broadband and High-Efficiency Microbump Antenna-on-Chip Based on Parasitic-Mode Control With Ultra-Thin Substrate","authors":"Xuan Liu;Huibo Wu;Yongjian Zhang;Wenhua Chen;Yue Li","doi":"10.1109/TTHZ.2026.3668391","DOIUrl":"https://doi.org/10.1109/TTHZ.2026.3668391","url":null,"abstract":"Microbump antenna offers a viable antenna-on-chip (AoC) solution to achieve high radiation efficiency using standard semiconductor processes. This letter presents a feasible method for broadening the bandwidth of terahertz microbump antenna while preserving its high efficiency. Instead of introducing additional microbump structures, two pairs of lossy parasitic strips are used to introduce high-efficiency parasitic resonance, while enabling differential mode in each strip pair to mitigate the in-band gain deterioration. The proposed antenna is fabricated using the 65 nm complementary metal-oxide-semiconductor process and the standard flip-chip technology. Compared with the existing on-chip microbump antennas, the proposed method enhances the bandwidth from 2.8% to 5.7%, achieving an efficiency of 42% and a gain of 3.85 dBi on a substrate with a thickness of 0.006<italic>λ</i>₀, providing an implementable solution for high-performance AoCs for subterahertz integrated circuits.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 5","pages":"607-611"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147734759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Low-Complexity Neural Equalizer for Nonlinear Compensation in Photonics-Assisted Terahertz Wireless Links Beyond 500 GHz","authors":"Liang Zhao;Yanyi Wang;Dongju Du;Yingxiong Song;Zhengxuan Li;Nan Ye;Qianwu Zhang;Junjie Zhang;Min Zhu;Jiao Zhang;Mingxu Wang;Jianjun Yu","doi":"10.1109/TTHZ.2025.3648184","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3648184","url":null,"abstract":"Photonics-assisted terahertz (THz) communication beyond 500 GHz has emerged as a key enabler for future 6G wireless networks, but faces critical signal impairments such as phase noise, intersymbol interference (ISI), and nonlinear distortion caused by optoelectronic devices. The deep convolutional neural network (Deep-CNN) equalizers have been utilized at the receiver digital signal processing to mitigate signal impairments. However, traditional Deep-CNN equalizers face the issue of high computational complexity. Thus, we propose and demonstrate a low-complexity nonlinear equalizer CNN-biGRU-Attention-pruning (CNN-biGRU-A-P) for a THz wireless communication beyond 500 GHz. We introduce <inline-formula><tex-math>$mathcal {L}_{1}$</tex-math></inline-formula> -structured pruning, knowledge distillation, and the AdamW optimizer into the model to significantly reduce computational complexity and parameter count, while keeping the accuracy degradation within 3%. The experimental results demonstrate that, compared to the traditional Deep-CNN, the proposed CNN-biGRU-A-P reduces computational complexity by 96.8% and achieves a gain in receiver sensitivity of 0.5–0.8 dB. Meanwhile, the number of parameters of CNN-biGRU-A-P is reduced by 93.2% compared to the traditional Deep-CNN. The proposed CNN-biGRU-A-P nonlinear equalizer maintains high performance while significantly reducing computational complexity, thereby offering an efficient approach to mitigating nonlinear impairments in THz wireless communication systems.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 5","pages":"525-537"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147734752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"170–400 GHz Ultra-Wideband and Low-Loss Power Splitter Based on Dielectric Silicon Rib Waveguides","authors":"Zhu Liang;Feifan Han;Zebin Huang;Zhuoyue Wen;Weichao Li;Xiongbin Yu;Xiaofeng Tao","doi":"10.1109/TTHZ.2026.3676177","DOIUrl":"https://doi.org/10.1109/TTHZ.2026.3676177","url":null,"abstract":"In this letter, an ultra-wideband 3-dB power splitter based on all-dielectric high-resistivity silicon rib waveguide is designed, fabricated, and experimentally validated. The device is composed of input–output tapers, an adiabatic tapered coupler, and s-bend rib waveguides. Simulation results indicate that the device achieves an ultra-wide 3-dB bandwidth of 462.6 GHz. Experimental characterization confirms that the splitter exhibits an average insertion loss of 0.32 dB and balanced power division with an absolute imbalance of less than 0.6 dB over the 170–400 GHz range, which covers the full WR-4.3 and WR-2.8 bands. In addition, the proposed 3-dB power splitter device is ideally suited for broadband and low-loss power division and provides a robust and scalable foundation for an integrated terahertz system.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 5","pages":"612-616"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147734712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 110–170 GHz Stacked-PCB-Based Pyramidal Horn Antenna With Flexible Stacking","authors":"Anyi Tian;Chenxin Liu;Alberto Hernández-Escobar;Takumi Kojima;Hiroyuki Sakai;Kazuaki Kunihiro;Takashi Tomura;Kenichi Okada","doi":"10.1109/TTHZ.2026.3664519","DOIUrl":"https://doi.org/10.1109/TTHZ.2026.3664519","url":null,"abstract":"This article presents a stacked-PCB-based broadband D-band horn antenna with high efficiency fabricated using a conventional PCB process. By replacing the conventional multilayered PCB with multiple stacked single-layer PCBs, the dielectric material inside the horn aperture is removed, and the antenna walls can be formed using vertically aligned through-holes. This architecture enables flexible stacking, allowing the aperture size to be scaled simply by adjusting the number of layers, which in turn scales the antenna gain. These modifications also lead to improved antenna characteristics, including gain and radiation pattern. The measured reflection coefficient remains below −18 dB across the entire D-band (110–170 GHz). The sidelobe is less than −10 dB and cross-polarization discrimination is lower than −30 dB. The gain is measured to be 19.8 <inline-formula><tex-math>$pm$</tex-math></inline-formula> 1.7 dB.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 5","pages":"555-563"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11395622","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147734720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THz Automotive Paint Thickness Sensing Leveraging Physics-Informed Neural Network","authors":"Yida Wu;Songbo Cui;Lin Du;Kaushik Sarker;Zijian Zhang;Jianghao Li;Mingxuan Zhang;Zehao Yang;Li Li;Xiaojun Wu","doi":"10.1109/TTHZ.2026.3656299","DOIUrl":"https://doi.org/10.1109/TTHZ.2026.3656299","url":null,"abstract":"The precise measurement of automotive paint thickness is directly related to the durability of the paint and perfection in appearance of the vehicle body, which in turn may affect the production cost and market competitiveness of the vehicle. How to realize contactless, high-precision and fast inspection of surface paint thickness has become an issue of great concern to the automobile industry. Terahertz (THz) electromagnetic waves have been proven to have strong penetration capabilities for paint materials. The precise measurement of automotive paint thickness deploying THz time-domain spectroscopy (TDS) has demonstrated significant application potentials. However, due to multiple layers of paint and the boundaries between layers being unclear, traditional THz TDS technology combined with model inversion algorithms exhibits significant instability, hindering the application of THz technology in automotive paint thickness measurement. In this work, we propose a physics-informed neural network algorithm, which is constructed entirely based on multilayer perceptron, without introducing any complex steps involving signal preprocessing and training strategies. In addition, we use a deep learning network based on long short-term memory to achieve effective discrimination of reflection signals from paint layers with a minimum thickness difference of 0.5 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m between layers. Notably, the model was deployed with a small training set, and the experiments show that the model is robust and stable on real datasets despite having increased parameters. The result exhibited an improved accuracy of about 3.3 and 4.3 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m for three-layer and five-layer paints, respectively, while making the minimum measurable thickness to 4.5 <inline-formula><tex-math>$mu$</tex-math></inline-formula>m. This experiment promotes further application of THz technology by revalidating the ability of THz TDS to realize nondestructive measurement of paint thickness for automotive painting, addressing the actual need of vehicle production lines.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 5","pages":"515-524"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147734736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IEEE Transactions on Terahertz Science and Technology Publication Information","authors":"","doi":"10.1109/TTHZ.2026.3682169","DOIUrl":"https://doi.org/10.1109/TTHZ.2026.3682169","url":null,"abstract":"","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"16 5","pages":"C3-C3"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11494164","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147734756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}