IEEE journal of microwaves最新文献

{"title":"A Radar-Based Concept for Simultaneous High-Resolution Imaging and Pixel-Wise Velocity Analysis for Tracking Human Motion","authors":"Johanna Bräunig;Simon Heinrich;Birte Coppers;Christoph Kammel;Vanessa Wirth;Marc Stamminger;Sigrid Leyendecker;Anna-Maria Liphardt;Ingrid Ullmann;Martin Vossiek","doi":"10.1109/JMW.2024.3453570","DOIUrl":"https://doi.org/10.1109/JMW.2024.3453570","url":null,"abstract":"The radar-based analysis of human motion is actively being researched due to its contact- and markerless nature and ability to measure motion directly via the Doppler effect. Especially in medical and biomechanical fields, precise movement analysis is crucial. However, existing radar-based studies typically exhibit low lateral resolution, focusing on velocity evaluations and the tracking of scattering centers resolvable in the range or Doppler domains. In this work, we present a novel concept that enables a pixel-wise velocity analysis of human motion in radar near-field imaging scenarios. For this, we utilize the well-established back-projection technique to reconstruct consecutive radar images and perform a subsequent pixel-wise phase comparison. To accurately capture pixel-specific velocities along the depth dimension, this is followed by corrections of near-field geometry distortions accounting for aperture properties and pixel positions. Our theoretical derivations are supported by comprehensive point target simulations. To assess the performance of the proposed approach, we conducted a proof-of-concept study. We tracked a hand surface's movement while performing a finger tapping motion and compared the fingertip position and velocity determined by the radar with the respective values obtained from an optical marker-based system. The results showed a velocity measurement accuracy of \u0000<inline-formula><tex-math>$8.1 ,mathrm{mms}^{-1}$</tex-math></inline-formula>\u0000 and a tracking accuracy of \u0000<inline-formula><tex-math>$1.4 ,mathrm{m}mathrm{m}$</tex-math></inline-formula>\u0000, demonstrating the great potential of our approach. The high angular resolution of the velocity measurement enables the tracking of the entire illuminated body shell, extending the range of future applications of radar-based motion analysis.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"639-652"},"PeriodicalIF":6.9,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10706625","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142408879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced Modeling of Circular Waveguide-Based Devices With Smooth Profiles Using Transformation Optics and Hierarchical Model Reduction","authors":"Giacomo Giannetti;Stefano Selleri;Gian Guido Gentili;Gines Garcia-Contreras;Juan Córcoles;Jorge A. Ruiz-Cruz","doi":"10.1109/JMW.2024.3454563","DOIUrl":"https://doi.org/10.1109/JMW.2024.3454563","url":null,"abstract":"A powerful and accurate analysis method for the full-wave analysis of circular waveguide-based devices is introduced. The method uses transformation optics, hierarchical model reduction, and the finite element method. First, transformation optics is applied to map the original device in a cylinder filled with an anisotropic and inhomogeneous medium. Second, exploiting a hierarchical model reduction approach, the electric field is expanded in terms of the modes of the circular waveguide in the transverse plane, while the longitudinal dependence of the fields is tackled by a 1D finite element method. The BCs are fulfilled rigorously. The 3D integrals arising from the discretization of the vector electric field equation are separable, thus allowing for solving radial and longitudinal integrals once and for all, while the angular integrals are the only ones to be computed for each specific device geometry. The limitations of the method are: (a) the input and output waveguides must be circular waveguides, even with different radii; (b) the device lateral surface must be expressed as a strictly-positive single-valued function in cylindrical coordinates; (c) the device profile must be smooth. The method is verified against full-wave simulations from commercial software and measurements available in the literature, showing good agreement and efficiency.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"675-689"},"PeriodicalIF":6.9,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10706872","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142408731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On Forward and Backward Modes in 1D Periodic Bounded Structures","authors":"Oskar Zetterstrom;Raúl Rodriguez-Berral;Francisco Mesa;Oscar Quevedo-Teruel","doi":"10.1109/JMW.2024.3451056","DOIUrl":"https://doi.org/10.1109/JMW.2024.3451056","url":null,"abstract":"We discuss the issue of identifying the forward/backward nature of modes in bounded one-dimensional periodic structures. This identification is based on the possibility of adequately and uniquely defining the phase velocity in these types of structure. We propose a general definition of phase velocity for one-dimensional scalar waves and show that, according to that general definition, the voltage and current waves in nonhomogeneous lossless transmission lines with positive per-unit-length capacitance and inductance are necessarily forward waves. We analyze in detail the particular case of periodic transmission lines and question the conclusions about the forward/backward nature of their modal solutions that are traditionally drawn from the inspection of the Brillouin diagrams. Numerical results for the case of corrugated parallel-plate waveguides support the idea that all modes can be considered forward-like as long as a periodic transmission line model remains a sensible and reliable description of the problem. In more general scenarios, we show that an appropriate definition of the phase velocity can still be found for electromagnetic waves with at least one linearly polarized field and that they are also necessarily forward waves if they propagate through media with positive \u0000<inline-formula><tex-math>$varepsilon$</tex-math></inline-formula>\u0000 and \u0000<inline-formula><tex-math>$mu$</tex-math></inline-formula>\u0000 parameters. Finally, we relate our discussion to the effective refractive index of periodic structures, highlighting that although its definition is not valid for a general periodic structure, it can be useful in many practical cases.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"690-705"},"PeriodicalIF":6.9,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10706633","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142408840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental Life-Cycle Assessment (LCA) of Wireless RF Systems: A Comparative Sustainability Analysis and a Microwave Engineers' Guide to LCA","authors":"Mahmoud Wagih;Andrew Bainbridge;Bashayer Alsulami;Jeff Kettle","doi":"10.1109/JMW.2024.3455575","DOIUrl":"https://doi.org/10.1109/JMW.2024.3455575","url":null,"abstract":"Information Communication and Technology (ICT) accounts for an increasing share of global Green House Gas (GHG) emissions. Wireless circuits and systems are indispensable in across all ICT sectors, from cellular networks through satellite communications, to the Internet of Things (IoT). While Life Cycle Assessment (LCA) is an industry-standard methodology for assessing the environmental impact of systems, there has been no comprehensive LCA study focusing on RF systems. We present the first comparative LCA specific to RF and microwave applications, and a design-for-sustainability guide covering mainstream RF applications. With Integrated Circuits (ICs) having the largest environmental impact, the trends in RFICs and MMICs are summarized and evaluated from an environmental perspective. Moving to mmWave frequencies, beyond 20 GHz, results in a shift to over 50% smaller node size above 28 GHz, but with minimal reduction in the core chip area, which inevitably increases the environmental footprint of 5G/6G mmWave systems. We then review active and passive microwave circuits focusing on phased array elements and filters, both distributed and lumped. A bespoke model for RF PCBs is also presented to model the surface finish and transmission line or antenna area accurately. Our LCA indicates that design choices such as the CMOS process, PCB material and surface finish, can have a large environmental impact at the manufacturing stage. We highlight the importance of low-loss components, comparing microstrip and LC filters, where a higher end-to-end RF system efficiency directly translates to a lower global warming potential (GWP), reducing Scope 2 GHG emissions.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"987-1000"},"PeriodicalIF":6.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10703165","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transmitarrays for Wireless Power Transfer on Earth and in Space","authors":"Jesse Brunet;Alex Ayling;Ali Hajimiri","doi":"10.1109/JMW.2024.3459859","DOIUrl":"https://doi.org/10.1109/JMW.2024.3459859","url":null,"abstract":"We present a space solar power system using transmitarrays for lowering the system's LCOE (Levelized Cost of Energy). We discuss the theoretical framework for transmitarrays in the context of wireless power transfer, including the transmission phase limit associated with layered frequency selective surfaces. We then present a proposal for using transmitarrays to lower the LCOE of space solar powered systems that are limited by the transmitting aperture size. Finally, we design and fabricate a low-cost, lightweight static transmitarray prototype and demonstrate a \u0000<inline-formula><tex-math>$sim$</tex-math></inline-formula>\u0000 2.4x increase in power transferred from the phased array transmitter to the rectenna receiver.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"934-945"},"PeriodicalIF":6.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10703104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 424 and 448 GHz Receiver for Aircraft Contrail Observations","authors":"Andy Fung;Pekka Kangaslahti;William Chun;Joelle Cooperrider;Javier Bosch-Lluis;Joan Munoz-Martin;Mary Soria;Erika Hernandez;Alan Tanner;Omkar Pradhan;Willam Deal;Caitlyn Cooke;Gerry Mei;Aaron Swanson;Khanh Nguyen","doi":"10.1109/JMW.2024.3450022","DOIUrl":"https://doi.org/10.1109/JMW.2024.3450022","url":null,"abstract":"Airplane produced contrail cirrus has a greenhouse effect in our atmosphere. It has an effect that is as much as or more than any other airplane emission such as airplane produced CO\u0000₂\u0000 Karcher et al. 2018. With air traffic anticipated to increase into the future it is important to understand contrail cirrus formation. We present a new receiver instrument using the 424 GHz (O\u0000₂\u0000) and 448 GHz (H\u0000₂\u0000O) emission lines for thermal and humidity profiling that will provide data to model airplane contrail formation. Such an instrument can be used for guiding aircraft flight paths to reduce the development of contrail cirrus that can have an immediate greenhouse effect in our atmosphere.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"928-933"},"PeriodicalIF":6.9,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10699383","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultra-Wideband Bistatic Radar Measurements of Snow","authors":"Omid Reyhanigalangashi;Siva-Prasad Gogineni;Drew Taylor;Shriniwas Kolpuke;Feras Abushakra;Jordan D. Larson;Aabhash Bhandari","doi":"10.1109/JMW.2024.3453941","DOIUrl":"https://doi.org/10.1109/JMW.2024.3453941","url":null,"abstract":"This paper presents the development of an ultra-wideband bistatic radar operating over the frequency range of 0.7–2.1 GHz based on the Radio-Frequency System-on-Chip (RF-SoC) platform and its application to snow measurements. The system utilizes Global Positioning System Disciplined Oscillators (GPS-DO) to synchronize the transmitter and receiver mounted on two small unmanned aerial systems (sUAS). We developed an arbitrary waveform generator to synthesize and transmit chirp signals. A data acquisition system was designed to capture signals with up to 2.2 GHz bandwidth and record the radar data. The transmit and receive antennas were developed using a four-element Vivaldi antenna array over the operating frequency range. Bistatic measurements were performed to determine the Brewster angle to estimate snow dielectric properties. The separation, incidence, and reflection angles were adjusted to collect radar data over an angular region extending from 27 to 68 degrees over snow at the Study of Precipitation, the Lower Atmosphere and Surface for Hydrometeorology (SPLASH) field site near Gothic, Colorado.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"894-905"},"PeriodicalIF":6.9,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10700996","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A D-Band Self-Packaged Low Loss Grounded Coplanar Waveguide to Rectangular Waveguide Transition With Silicon-Based Air Cavity-Backed Structure","authors":"Zi-Qi Zhang;Xiao-Long Huang;Liang Zhou;Yin-Shan Huang;Cheng-Rui Zhang","doi":"10.1109/JMW.2024.3459909","DOIUrl":"https://doi.org/10.1109/JMW.2024.3459909","url":null,"abstract":"A novel D-band self-packaged silicon-based air cavity-backed transition from grounded coplanar waveguide to air-filled rectangular waveguide was investigated, fabricated, and measured in this work. The equivalent circuit model was established and analyzed in detail, and design procedures are given. The calculated, simulated, and measured S-parameters of the transition show some agreement. The minimum measured insertion loss of the proposed transition is 1.1 dB at 147 GHz with a fractional 3-dB bandwidth of 10.2%. This transition demonstrates outstanding performance of low loss and profile compared with state-of-the art works in our in-house silicon-based MEMS photosensitive composite film fabrication process. It can be further used in a high-performance joint radar communication system in packaging.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"767-776"},"PeriodicalIF":6.9,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10699397","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142408877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ordinary and Extraordinary Permittivities of 4H SiC at Different Millimeter-Wave Frequencies, Temperatures, and Humidities","authors":"Tianze Li;Lei Li;Xiaopeng Wang;James C. M. Hwang;Shana Yanagimoto;Yoshiyuki Yanagimoto","doi":"10.1109/JMW.2024.3453325","DOIUrl":"https://doi.org/10.1109/JMW.2024.3453325","url":null,"abstract":"Hexagonal semiconductors such as 4H SiC have important high-frequency, high-power, and high-temperature applications. The applications require accurate knowledge of both ordinary and extraordinary relative permittivities, \u0000<italic>ϵ</i>\u0000_⊥\u0000 and \u0000<italic>ϵ</i>\u0000_||\u0000, perpendicular and parallel, respectively, to the c axis of these semiconductors. However, due to challenges for suitable test setups and precision high-frequency measurements, little reliable data exists for these semiconductors especially at millimeter-wave frequencies. Recently, we reported \u0000<italic>ϵ</i>\u0000_||\u0000 of 4H SiC from 110 to 170 GHz. This paper expands on the previous report to include both \u0000<italic>ϵ</i>\u0000_⊥\u0000 and \u0000<italic>ϵ</i>\u0000_||\u0000 of the same material from 55 to 330 GHz, as well as their temperature and humidity dependence enabled by improving the measurement precision to two decimal points. For example, at room temperature, real \u0000<italic>ϵ</i>\u0000_⊥\u0000 and \u0000<italic>ϵ</i>\u0000_||\u0000 are constant at 9.77 ± 0.01 and 10.20 ± 0.05, respectively. By contrast, the ordinary loss tangent increases linearly with the frequency \u0000<italic>f</i>\u0000 in the form of (4.9 ± 0.1) × 10\u0000⁻¹⁶\u0000 \u0000<italic>f</i>\u0000. The loss tangent, less than 1 × 10\u0000⁻⁴\u0000 over most millimeter-wave frequencies, is significantly lower than that of sapphire, our previous low-loss standard. Finally, both \u0000<italic>ϵ</i>\u0000_⊥\u0000 and \u0000<italic>ϵ</i>\u0000_||\u0000 have weak temperature coefficients on the order of 10\u0000⁻⁴\u0000 /°C. The knowledge reported here is especially critical to millimeter-wave applications of 4H SiC, not only for solid-state devices and circuits, but also as windows for high-power vacuum electronics.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"666-674"},"PeriodicalIF":6.9,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10684839","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142408730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards Detecting Climate Change Effects With UAV-Borne Imaging Radars","authors":"Ingrid Ullmann;Christina Bonfert;Alexander Grathwohl;Mohamed Amine Lahmeri;Victor Mustieles-Pérez;Julian Kanz;Elena Sterk;Frederik Bormuth;Roghayeh Ghasemi;Patrick Fenske;Michelangelo Villano;Robert Schober;Robert F. H. Fischer;Gerhard Krieger;Christian Damm;Christian Waldschmidt;Martin Vossiek","doi":"10.1109/JMW.2024.3450015","DOIUrl":"https://doi.org/10.1109/JMW.2024.3450015","url":null,"abstract":"Climate change is associated with a variety of environmental phenomena, such as the melting of glaciers, the drying out of crops and soils, and an increase in the risk of avalanches. To detect and monitor these changes, satellite-based radar imaging is widely used, as it enables the large-scale mapping of the Earth's surface independent of weather and sunlight. An emerging field of research is to use radar systems mounted on unmanned aerial vehicles (UAVs) for this purpose. UAV-borne radar systems image smaller areas, but can capture them in greater detail, more flexibly in terms of flight trajectory, and at shorter repetition intervals. This article presents the capabilities of UAV-based radar systems and the associated challenges in terms of system design and imaging techniques for detecting and monitoring the effects of climate change. Current research results are shown. In addition, we give an outlook on using a swarm of cooperative UAVs, each carrying a radar. UAV swarms will enable a higher imaging quality with respect to resolution and detectability, but at the same time come with a number of additional challenges, which will be discussed in the paper as well.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"4 4","pages":"881-893"},"PeriodicalIF":6.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10683959","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}