IEEE Transactions on Terahertz Science and Technology最新文献

{"title":"Measurements and Verification of an Antenna Pattern-Based Tracking Algorithm at 300 GHz","authors":"Tobias Doeker;Lorenz H. W. Loeser;Thomas Kürner","doi":"10.1109/TTHZ.2025.3555599","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3555599","url":null,"abstract":"For wireless communication systems, beam tracking is crucial if the transmitter and/or the receiver is nonstatic. Specifically, for a communication system in the low terahertz frequency range, beam tracking becomes mandatory due to the necessity for highly directive antennas with narrow beams. Therefore, a beam tracking algorithm for horn antennas specified for 300 GHz has been developed. The proposed algorithm uses changes in antenna gain due to the movement of the transmitter and/or receiver. The received power and information about the antenna radiation pattern allow for the prediction of the angle of departure and angle of arrival. Basic verification of the algorithm has already been conducted through simulation and should now be verified under real conditions through measurements. This article presents a measurement campaign conducted with a channel sounding system around 300 GHz. According to the description of the algorithm provided at the beginning of this article, the measurement results are evaluated for both line-of-sight and non-line-of-sight scenarios. The measurement data are used as input for the algorithm to investigate the possibilities of beam tracking in a real system. It is shown that the algorithm can reliably predict angular changes in both line-of-sight and non-line-of-sight cases. With an accuracy of <inline-formula><tex-math>$pm$</tex-math></inline-formula> 1<inline-formula><tex-math>$^{circ }$</tex-math></inline-formula>, angular changes of up to 20<inline-formula><tex-math>$^{circ }$</tex-math></inline-formula> can be tracked using information from four different transmitter and receiver antenna combinations. Even higher angular ranges, up to 70<inline-formula><tex-math>$^{circ }$</tex-math></inline-formula> in the line-of-sight case and 45<inline-formula><tex-math>$^{circ }$</tex-math></inline-formula> in the non-line-of-sight case, can be tracked if the accuracy value is increased to <inline-formula><tex-math>$pm$</tex-math></inline-formula> 4<inline-formula><tex-math>$^{circ }$</tex-math></inline-formula>. The proposed algorithm has, thus, been verified both through simulation and real measurements.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 3","pages":"359-369"},"PeriodicalIF":3.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904627","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":"Gouy Phase Correction for Quasioptical, Dielectric Spectroscopy of Spherical Shells in a Gaussian Beam for Terahertz Corneal Sensing","authors":"Roman Grigorev;Faezeh Zarrinkhat;Joel Lamberg;Irina Nefedova;Mohammad Mirmoosa;Juha Ala-Laurinaho;Aleksi Tamminen;Zachary Taylor","doi":"10.1109/TTHZ.2025.3551619","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3551619","url":null,"abstract":"This study aims to explore the effect of the Gouy phase shift correction on determining refractive index and physical thickness of concentric spherical shells measured by quasioptical terahertz (THz) spectroscopy. The shells consisted of a loss-free quartz layer sitting on a water core which serves as an aqueous half space similar to the cornea's aqueous humour. The reflection of the water-backed quartz shells were measured with a focused Gaussian beam in the 220–330 GHz range. The optics generated a beam with a frequency-independent confocal distance resulting in equal radius of curvature and thus optimal wavefront matching to the sample curvature across the band. Thickness and refractive index were estimated from the measurements using Fresnel’s equations and a fixed phase velocity. Parameter extraction was performed a second time where the frequency and axial location dependent phase velocity was corrected by incorporating the expected Gouy phase shift. The correction improved both the thickness and refractive index accuracy. The utility of Gouy phase correction was explored on hydrated corneal phantoms and increased the accuracy of thickness, and anterior and posterior water content estimates.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 3","pages":"370-378"},"PeriodicalIF":3.9,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904666","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":"An InP Distributed Active Isolator With >30-dB Isolation Over 215-GHz Bandwidth for Sub-THz Wideband Transceivers","authors":"Phat T. Nguyen;Natalie S. Wagner;Alexander Stameroff;Anh-Vu Pham","doi":"10.1109/TTHZ.2025.3550802","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3550802","url":null,"abstract":"This article presents a 5–220-GHz active isolator with >50 to >30 dB reverse isolation to protect local oscillators in sub-THz wideband transceivers. The isolator design adopts a Darlington distributed amplifier topology comprised of five high-isolation stages to achieve a flat forward transmission and wideband input/output matchings. To achieve a high isolation across the wide bandwidth, the isolator codesigns stacked heterojunction bipolar transistor (HBT) topology and high-isolation layout structures, building high-isolation stages for the complete isolator. A new layout arrangement using low-crosstalk transmission lines, high-isolation cell shielding, and coplanar waveguides with continuous ground planes is presented and implemented to mitigate couplings that severely degrade isolation at sub-THz frequencies. The indium phosphide active isolator is fabricated and characterized. The prototype exhibits a forward gain of 10 dB and a reverse isolation of >50, >37, and >30 dB up to 40, 190, and 220 GHz, respectively. The maximum saturated power and the output 1-dB compression point are 15.8 and 12.2 dBm, respectively. From 120 to 170 GHz, the output third-order intercept point is from 21.4 to 16.1 dBm. The isolator consumes 45 mA of current with an active area size of 0.176 mm².","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 3","pages":"440-455"},"PeriodicalIF":3.9,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904603","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":"Unveiling the Origin of Spurious Features in THz-TDS of Powder Compacts","authors":"Jon Gorecki;Keir N. Murphy;Daniel Markl;Andrew D. Burnett;Mira Naftaly","doi":"10.1109/TTHZ.2025.3549944","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3549944","url":null,"abstract":"Terahertz time-domain spectroscopy (THz-TDS) is a vital tool for scientific and industrial analysis, however, many commonly analyzed products, such as those found in pharmaceutical, agriculture, and mining sectors, are produced as powders or granular materials, and these sample morphologies have been reported to produce anomalous spectral features which can often obscure known material resonances. The cause of these anomalous features has been poorly understood, making it difficult to predict their presence and limiting the applicability of THz–TDS for such materials. Here, we systematically study how the sample morphology of granular compacts produces anomalous spectral features by performing extensive experimental measurements on two-part powder compacts with varying microsphere size and concentration. Further, we employ ray-tracing simulations to identify the physical mechanism whereby these spectral features arise owing to variations in optical path length within the heterogeneous sample. We believe this is the first time that the physical cause of spurious spectral features within powder samples has been adequately explained and that a robust method has been presented for modeling this effect. By understanding these features, we propose that instead of being seen as a parasitic effect, their presence can be utilised to extract morphological properties of the samples, thereby enhancing the utility of THz-TDS for granular materials.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 3","pages":"418-430"},"PeriodicalIF":3.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904604","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":"Terahertz Metamaterial Sensor With Embedded Microfluidic Channels for Real-Time Liquid Analytes Sensing","authors":"Xue Li;Jingye Sun;Fangjing Hu;Qing You;Yuning Li;Tao Deng","doi":"10.1109/TTHZ.2025.3548847","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3548847","url":null,"abstract":"The vibrational and rotational energy levels of numerous biological macromolecules fall within the terahertz (THz) range, making THz spectroscopy a viable method for identifying biological samples. However, most biomolecular activities can only be observed in a liquid environment. Being a polar substance, water exhibits strong absorption characteristics toward THz waves. In this study, we proposed a novel THz metamaterial sensor with embedded microfluidic channels fabricated in the PDMS substrate that operates in reflective modes. This approach not only enables the reduction of THz wave absorptions by water by decreasing the volume of the liquid sample but also realizes the real-time detection of liquid samples. Simulated results reveal that the double splits ring resonators (DSRRs) metal structure exhibits two resonant dips below 1 THz, with a maximum figure of merit of 0.77 RIU^-1. Meanwhile, the sensors show significant resonant frequencies red-shifts as the refractive index for the analytes varies in the microchannels. Moreover, the split ring resonators with two gaps (SRRsTG) and DSRRs sensors were fabricated and demonstrated using a THz time-domain spectroscopy system. It has been found that the experimental results are in good agreement with the simulation results when the microchannels are empty (air). The sensors are capable of distinguishing various liquid analytes (e.g., water, acetone, and alcohol) by observing the shifts and amplitude variations for two resonant frequencies under different electric field polarizations. In addition, the DSRRs sensors show higher sensitivities in comparison to those of SRRsTG sensors, giving frequency shifts up to 92.1 GHz in TE mode and 192.3 GHz in TM mode for alcohol (99.7%) detections. The presented approach has been easily realized by standard lithography methods and could be applied to other metamaterial structures, as well as for biological sample detections.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 3","pages":"379-388"},"PeriodicalIF":3.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904665","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":"Ultra-Thin Film Sensing With Terahertz Subwavelength Thin Disc Microresonators","authors":"Kane H.J. Hill;Dominik Walter Vogt","doi":"10.1109/TTHZ.2025.3548856","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3548856","url":null,"abstract":"Subwavelength thin disc terahertz microresonators have been proven to exhibit unprecedented quality factors, exceptionally low losses and extensive evanescent fields. We investigate the microresonators' potential for ultra-thin film sensing using poly(methyl methacrylate) films for a compelling proof-of-concept. Highly subwavelength thin films (<inline-formula><tex-math>$lambda$</tex-math></inline-formula>/10 000) with thicknesses of tens of nanometers were deposited atop the thin disc microresonator, each causing a pronounced frequency shift and a marked reduction in the intrinsic quality factor; these differences were measurable using a standard continuous-wave terahertz spectrometer with an added terahertz microresonator frequency reference. This demonstration benchmarks the exceptional sensitivity of thin disc terahertz microresonators, and, to our knowledge, marks the first recorded use of a whispering-gallery mode resonator for ultra-thin film sensing in the THz domain. Our findings create exciting possibilities for future applications, such as detecting ultra-thin films of sophisticated analytes.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 3","pages":"412-417"},"PeriodicalIF":3.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10916966","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904617","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":"SubTHz Fully-Metallic Geodesic Luneburg Lens Antenna","authors":"Pilar Castillo-Tapia;Shiyi Yang;Angel Palomares-Caballero;Jean-Paul Guillet;N. J. G. Fonseca;Oscar Quevedo-Teruel","doi":"10.1109/TTHZ.2025.3548452","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3548452","url":null,"abstract":"We propose and validate experimentally a fully metallic geodesic Luneburg lens antenna operating in the subTHz band. The antenna produces three beams pointing at 0<inline-formula><tex-math>$^circ$</tex-math></inline-formula>, 40<inline-formula><tex-math>$^circ$</tex-math></inline-formula>, and <inline-formula><tex-math>$-$</tex-math></inline-formula>40<inline-formula><tex-math>$^circ$</tex-math></inline-formula>. To facilitate the integration, the geodesic lens is folded to reduce its height to approximately 38.7% of the original Rinehart–Luneburg lens. To reduce potential leakage resulting from manufacturing and assembly tolerances at subTHz frequencies, the waveguide feeding structure has a deliberate small air gap alongside electromagnetic bandgap structures. This enhancement aims to bolster the robustness of the antenna, ensuring stable performance even in the presence of misalignments. The results demonstrate the robustness of geodesic lenses in the subTHz regime; showing their suitability for applications that require multibeam antennas at these high frequencies. The successful performance of geodesic lenses in the subTHz regime confirms its potential for operation at higher frequencies above 300 GHz.","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 3","pages":"514-518"},"PeriodicalIF":3.9,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10914556","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904630","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.2025.3544854","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3544854","url":null,"abstract":"","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 2","pages":"C2-C2"},"PeriodicalIF":3.9,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10910275","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553172","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 Open Access Publishing","authors":"","doi":"10.1109/TTHZ.2025.3544945","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3544945","url":null,"abstract":"","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 2","pages":"304-304"},"PeriodicalIF":3.9,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10910283","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553390","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 Transactions on Terahertz Science and Technology Publication Information","authors":"","doi":"10.1109/TTHZ.2025.3544898","DOIUrl":"https://doi.org/10.1109/TTHZ.2025.3544898","url":null,"abstract":"","PeriodicalId":13258,"journal":{"name":"IEEE Transactions on Terahertz Science and Technology","volume":"15 2","pages":"C3-C3"},"PeriodicalIF":3.9,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10910279","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553373","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}