Implantable medical devices (IMDs) are essential for life-saving healthcare advancements worldwide, enabling wireless remote monitoring capabilities. These capabilities include telemetry, wireless power transfer (WPT), and data communication. Modern active IMDs rely on robust wireless communication systems to transmit essential data, such as physiological information, diagnostic details, and parameters critical for optimizing therapies, both externally and among implantable subsystems. Fundamental communication techniques include optical, radiofrequency (RF), and ultrasonic. Achieving effective IMD communication through biological tissue requires careful consideration of the transmission modality to ensure safety and seamless integration with external systems. This paper examines the most widely adopted communication modalities, drawing insights from 56 research studies published over the past six years, with a particular emphasis on RF technology, which is favored for wireless IMDs due to recent progress in implantable antenna designs and WPT. These technological advancements have led to the development of compact, high-performance antennas that reduce interference, save power, and enable high-speed data transmission rates, establishing RF as the preferred modality for reliable and seamless communication in IMDs and opening up exciting possibilities for the future of healthcare technology.
{"title":"Innovations and Challenges in RF Antenna Technologies for Implantable Medical Devices Communication","authors":"Mohamed Benaissa;Abdelhalim Chaabane;Hussein Attia;Ibraheem Al-Naib","doi":"10.1109/JMW.2025.3555480","DOIUrl":"https://doi.org/10.1109/JMW.2025.3555480","url":null,"abstract":"Implantable medical devices (IMDs) are essential for life-saving healthcare advancements worldwide, enabling wireless remote monitoring capabilities. These capabilities include telemetry, wireless power transfer (WPT), and data communication. Modern active IMDs rely on robust wireless communication systems to transmit essential data, such as physiological information, diagnostic details, and parameters critical for optimizing therapies, both externally and among implantable subsystems. Fundamental communication techniques include optical, radiofrequency (RF), and ultrasonic. Achieving effective IMD communication through biological tissue requires careful consideration of the transmission modality to ensure safety and seamless integration with external systems. This paper examines the most widely adopted communication modalities, drawing insights from 56 research studies published over the past six years, with a particular emphasis on RF technology, which is favored for wireless IMDs due to recent progress in implantable antenna designs and WPT. These technological advancements have led to the development of compact, high-performance antennas that reduce interference, save power, and enable high-speed data transmission rates, establishing RF as the preferred modality for reliable and seamless communication in IMDs and opening up exciting possibilities for the future of healthcare technology.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"526-542"},"PeriodicalIF":6.9,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10978852","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925004","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}
Separability, detection capability, and height estimation performance are key measures of high performance 4D imaging radars. While many different sensors have been presented in recent years, no sensor-independent comparison of the performance achievable with differing array realizations was given. Therefore, in this work in total 113 sub-arrays of one large uniform rectangular array are analyzed. Measurements of real-world scenarios are performed with a high-resolution 4D imaging radar system with 1728 virtual channels on the static edge case to assess the performance in the angular domain. Regarding the above-mentioned performance criteria, three main conclusions can be derived from the performed analysis: Although the angular resolution depends on the array size, the separation capability of objects with small radar cross section from stronger ones depends on the channel count and not the aperture size. In scenarios with many targets located in the mid-range of the sensor, the detection capability increases at a constant channel count for smaller arrays with a lower sparsity in contrast to larger ones with less channels. Hereby, increasing the fill factor while keeping the aperture size constant is more beneficial to the performance than increasing the aperture size while keeping the fill factor constant.
{"title":"Influence of Channel Count and Array Sparsity on the Detection Performance of 4D Imaging Radars","authors":"Dominik Schwarz;Matthias Linder;Veronika Kienle;Nico Riese;Christian Waldschmidt","doi":"10.1109/JMW.2025.3560661","DOIUrl":"https://doi.org/10.1109/JMW.2025.3560661","url":null,"abstract":"Separability, detection capability, and height estimation performance are key measures of high performance 4D imaging radars. While many different sensors have been presented in recent years, no sensor-independent comparison of the performance achievable with differing array realizations was given. Therefore, in this work in total 113 sub-arrays of one large uniform rectangular array are analyzed. Measurements of real-world scenarios are performed with a high-resolution 4D imaging radar system with 1728 virtual channels on the static edge case to assess the performance in the angular domain. Regarding the above-mentioned performance criteria, three main conclusions can be derived from the performed analysis: Although the angular resolution depends on the array size, the separation capability of objects with small radar cross section from stronger ones depends on the channel count and not the aperture size. In scenarios with many targets located in the mid-range of the sensor, the detection capability increases at a constant channel count for smaller arrays with a lower sparsity in contrast to larger ones with less channels. Hereby, increasing the fill factor while keeping the aperture size constant is more beneficial to the performance than increasing the aperture size while keeping the fill factor constant.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"616-630"},"PeriodicalIF":6.9,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10979294","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925336","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}
Pub Date : 2025-04-25DOI: 10.1109/JMW.2025.3554213
Zhen Yue;Xin Xu;Si Hui Wu;Xian Qi Lin
This paper proposes an efficient and wide dynamic range rectifier based on power reflection structure. The rectifier consists of a branch-line coupler and two sub-rectifiers operating at different input power levels. The branch-line coupler is used as power reflection structure. Due to the electromagnetic symmetry of the branch-line coupler and the non-linear characteristics of the rectifier, the power reflection structure can reflect mismatched energy caused by load variations or input power fluctuations back into the sub-rectifier, which can improve the reflection coefficient of the rectifier. For validation in different application scenarios, two rectifiers operating at 5.8 GHz were designed, fabricated, and characterized. For the proposed rectifier I (with load resistances RL1 = 750Ω and RL2 = 300Ω), the measured PCE maintains exceeding 50% when the input power ranges from 8 to 29.2 dBm, and the peak PCE is 68.01% at 18 dBm input power. While for rectifier II (with load resistances RL3 = 800Ω and RL4 = 300Ω), the measured PCE remains over 50% with input power from −1.2 to 28.8 dBm, and the peak PCE is 68.51% at 15 dBm input power. Theoretical analysis and performance comparison are carried out that excellent performance of proposed rectifiers in extending the input power range, which can widely apply in WPT system.
{"title":"High-Efficiency and Wide-Dynamic-Range Rectifier Based on Power Reflection for Wireless Power Transfer in Sensor Networks","authors":"Zhen Yue;Xin Xu;Si Hui Wu;Xian Qi Lin","doi":"10.1109/JMW.2025.3554213","DOIUrl":"https://doi.org/10.1109/JMW.2025.3554213","url":null,"abstract":"This paper proposes an efficient and wide dynamic range rectifier based on power reflection structure. The rectifier consists of a branch-line coupler and two sub-rectifiers operating at different input power levels. The branch-line coupler is used as power reflection structure. Due to the electromagnetic symmetry of the branch-line coupler and the non-linear characteristics of the rectifier, the power reflection structure can reflect mismatched energy caused by load variations or input power fluctuations back into the sub-rectifier, which can improve the reflection coefficient of the rectifier. For validation in different application scenarios, two rectifiers operating at 5.8 GHz were designed, fabricated, and characterized. For the proposed rectifier I (with load resistances RL1 = 750Ω and RL2 = 300Ω), the measured PCE maintains exceeding 50% when the input power ranges from 8 to 29.2 dBm, and the peak PCE is 68.01% at 18 dBm input power. While for rectifier II (with load resistances RL3 = 800Ω and RL4 = 300Ω), the measured PCE remains over 50% with input power from −1.2 to 28.8 dBm, and the peak PCE is 68.51% at 15 dBm input power. Theoretical analysis and performance comparison are carried out that excellent performance of proposed rectifiers in extending the input power range, which can widely apply in WPT system.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"666-676"},"PeriodicalIF":6.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10976594","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925267","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}
Pub Date : 2025-04-23DOI: 10.1109/JMW.2025.3559355
Antonio Manuel Huéscar de la Cruz;Antonio Oliva Aparicio;Fernando D. Quesada Pereira;Alejandro Álvarez Melcón;Vicente E. Boria Esbert
In this contribution, an Integral Equation (IE) formulation is proposed for the analysis of microwave circuits, based on the junction of two different rectangular waveguides coupled by an arbitrarily shaped zero thickness discontinuity. These rectangular waveguides could include an unlimited number of conducting elements with arbitrary shapes inside them. To solve the IE, the problem is split into two equivalent subproblems, each of which is related to a rectangular waveguide. Subsequently, an equivalent surface magnetic current density ($vec{mathrm{mathbf{M}}}_{text{ap}}$) defined at the discontinuity is used to connect the equivalent problems of each rectangular waveguide. In order to reduce the number of unknowns, the Lorenz gauge Green's functions of rectangular waveguides and their spatial derivatives are used to model the boundary conditions. In addition, the Ewald method has been employed to significantly speed up the evaluation of these rectangular waveguide Green's functions. Therefore, the use of this surface magnetic current density can reduce in some configurations the number of unknowns compared to an alternative Electric Field Integral Equation (EFIE). In addition, it allows a simpler analysis of some kind of discontinuities with respect to an EFIE method. Finally, the proposed technique has been validated by comparison with the results provided by commercial full-wave software tools such as Ansys HFSS and CST Studio Suite, showing good agreement and a better numerical efficiency.
在这篇贡献中，基于任意形状的零厚度不连续耦合的两个不同矩形波导的结，提出了一个用于分析微波电路的积分方程（IE）公式。这些矩形波导可以包含无限数量的内部形状任意的导电元件。为了解决IE，这个问题被分成两个等价的子问题，每个子问题都与矩形波导有关。随后，利用在不连续点处定义的等效表面磁电流密度$vec{ mathm {mathbf{M}}}_{text{ap}}$来连接各矩形波导的等效问题。为了减少未知量，采用矩形波导的洛伦兹规范格林函数及其空间导数来模拟边界条件。此外，采用Ewald方法显著加快了矩形波导格林函数的计算速度。因此，与另一种电场积分方程（EFIE）相比，使用这种表面磁流密度可以在某些配置中减少未知数的数量。此外，它还允许用EFIE方法对某种不连续点进行更简单的分析。最后，通过与Ansys HFSS和CST Studio Suite等商用全波软件工具提供的结果进行对比，验证了所提方法的正确性和数值效率。
{"title":"Efficient Integral Equation Analysis of Arbitrarily Shaped Rectangular Waveguide Discontinuities Including Conducting Objects","authors":"Antonio Manuel Huéscar de la Cruz;Antonio Oliva Aparicio;Fernando D. Quesada Pereira;Alejandro Álvarez Melcón;Vicente E. Boria Esbert","doi":"10.1109/JMW.2025.3559355","DOIUrl":"https://doi.org/10.1109/JMW.2025.3559355","url":null,"abstract":"In this contribution, an Integral Equation (IE) formulation is proposed for the analysis of microwave circuits, based on the junction of two different rectangular waveguides coupled by an arbitrarily shaped zero thickness discontinuity. These rectangular waveguides could include an unlimited number of conducting elements with arbitrary shapes inside them. To solve the IE, the problem is split into two equivalent subproblems, each of which is related to a rectangular waveguide. Subsequently, an equivalent surface magnetic current density (<inline-formula><tex-math>$vec{mathrm{mathbf{M}}}_{text{ap}}$</tex-math></inline-formula>) defined at the discontinuity is used to connect the equivalent problems of each rectangular waveguide. In order to reduce the number of unknowns, the Lorenz gauge Green's functions of rectangular waveguides and their spatial derivatives are used to model the boundary conditions. In addition, the Ewald method has been employed to significantly speed up the evaluation of these rectangular waveguide Green's functions. Therefore, the use of this surface magnetic current density can reduce in some configurations the number of unknowns compared to an alternative Electric Field Integral Equation (EFIE). In addition, it allows a simpler analysis of some kind of discontinuities with respect to an EFIE method. Finally, the proposed technique has been validated by comparison with the results provided by commercial full-wave software tools such as Ansys HFSS and CST Studio Suite, showing good agreement and a better numerical efficiency.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"739-749"},"PeriodicalIF":6.9,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10975046","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925001","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}
Pub Date : 2025-04-21DOI: 10.1109/JMW.2025.3555839
Adam Der;Taylor Barton
This work presents an active impedance matching technique to extend the bandwidth of a power amplifier (PA). The architecture is similar to that of the load-modulated balanced amplifier, but employs phase-only control to avoid the complexity and gain compression characteristics associated with millimeter-wave load-modulated PAs. To evaluate the effectiveness of the technique and fully explore the design space, four monolithic microwave integrated circuit (MMIC) PA variants are fabricated and compared through measurements. Specifically, load-pull characterization of the best-case performance of the single-ended PA used in the active match balanced amplifier is compared to the overall active match architecture to identify and understand the sources of losses in the system. The primary active match design demonstrates a wideband operation from 18 to 44 GHz, with an output power of 28-31 dBm and a power-added efficiency (PAE) of 12–31% in continuous-wave (CW) measurements.
{"title":"An 18–44 GHz Power Amplifier in 90-nm GaN Using Active Impedance Matching","authors":"Adam Der;Taylor Barton","doi":"10.1109/JMW.2025.3555839","DOIUrl":"https://doi.org/10.1109/JMW.2025.3555839","url":null,"abstract":"This work presents an active impedance matching technique to extend the bandwidth of a power amplifier (PA). The architecture is similar to that of the load-modulated balanced amplifier, but employs phase-only control to avoid the complexity and gain compression characteristics associated with millimeter-wave load-modulated PAs. To evaluate the effectiveness of the technique and fully explore the design space, four monolithic microwave integrated circuit (MMIC) PA variants are fabricated and compared through measurements. Specifically, load-pull characterization of the best-case performance of the single-ended PA used in the active match balanced amplifier is compared to the overall active match architecture to identify and understand the sources of losses in the system. The primary active match design demonstrates a wideband operation from 18 to 44 GHz, with an output power of 28-31 dBm and a power-added efficiency (PAE) of 12–31% in continuous-wave (CW) measurements.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"702-710"},"PeriodicalIF":6.9,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10971220","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925220","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}
Electric vehicles (EV) have the potential to reduce greenhouse gas emissions, improve air quality, and lower mobility costs, thus promoting sustainable mobility. Battery management is crucial in electric vehicles to ensure safety, maximize battery lifespan, maintain optimal performance, and improve energy efficiency. However, the complex wiring harnesses required to transport sensor data make a Battery Management System (BMS) a complex and vulnerable block in EV design. This is due to weight and cost associated with extensive wiring harnesses, high connection failures probability, challenging maintenance, and limited flexibility in battery pack configuration. Researchers and manufacturers envisage a potential solution in Wireless BMS (wBMS) to improve EV safety, reduce weight, improve scalability, and enhance reliability by eliminating complex wiring. The state-of-the-art wBMS use wireless sensors, that themselves require a battery to operate, therefore, posing an additional liability and failure threat. Luckily, energy autonomous wireless sensors can be cutting-edge technology to irradicate this vulnerability and give the wBMS designers and manufacturers with the huge flexibility to further enhance reliability, reduce maintenance, lower weight, and improve environmental sustainability by eliminating the need for sensor battery replacements. This survey intends to summarize the recent contributions and developments made in providing the solutions for wBMS in automotive applications. A comprehensive review and analysis of power consumption of common communication standards used in wBMS is also provided. The potential of battery-free RFID (UHF/NFC) sensors in realizing energy autonomous wBMS for electric vehicles has been unearthed, several use cases, commercially available solutions and their practical application in automotive industry have been discussed. Moreover, this review serves as a useful guide for industry professionals and researchers developing battery-free passive wBMS, covering current advancements in battery-free passive wireless sensor technology, technology readiness, real-world operational challenges, and future trends.
{"title":"A Way Towards Energy Autonomous Wireless Sensing for EV Battery Management System","authors":"Badar Muneer;Valentina Palazzi;Federico Alimenti;Paolo Mezzanotte;Luca Roselli","doi":"10.1109/JMW.2025.3557211","DOIUrl":"https://doi.org/10.1109/JMW.2025.3557211","url":null,"abstract":"Electric vehicles (EV) have the potential to reduce greenhouse gas emissions, improve air quality, and lower mobility costs, thus promoting sustainable mobility. Battery management is crucial in electric vehicles to ensure safety, maximize battery lifespan, maintain optimal performance, and improve energy efficiency. However, the complex wiring harnesses required to transport sensor data make a Battery Management System (BMS) a complex and vulnerable block in EV design. This is due to weight and cost associated with extensive wiring harnesses, high connection failures probability, challenging maintenance, and limited flexibility in battery pack configuration. Researchers and manufacturers envisage a potential solution in Wireless BMS (wBMS) to improve EV safety, reduce weight, improve scalability, and enhance reliability by eliminating complex wiring. The state-of-the-art wBMS use wireless sensors, that themselves require a battery to operate, therefore, posing an additional liability and failure threat. Luckily, energy autonomous wireless sensors can be cutting-edge technology to irradicate this vulnerability and give the wBMS designers and manufacturers with the huge flexibility to further enhance reliability, reduce maintenance, lower weight, and improve environmental sustainability by eliminating the need for sensor battery replacements. This survey intends to summarize the recent contributions and developments made in providing the solutions for wBMS in automotive applications. A comprehensive review and analysis of power consumption of common communication standards used in wBMS is also provided. The potential of battery-free RFID (UHF/NFC) sensors in realizing energy autonomous wBMS for electric vehicles has been unearthed, several use cases, commercially available solutions and their practical application in automotive industry have been discussed. Moreover, this review serves as a useful guide for industry professionals and researchers developing battery-free passive wBMS, covering current advancements in battery-free passive wireless sensor technology, technology readiness, real-world operational challenges, and future trends.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"555-571"},"PeriodicalIF":6.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10967547","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925332","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}
Pub Date : 2025-04-15DOI: 10.1109/JMW.2025.3554050
Patrick Fenske;Tobias Koegel;Roghayeh Ghasemi;Danielle Gunders-Hunt;Martin Vossiek
Radar imaging performance can be significantly improved by creating synthetic apertures along a radar sensor's trajectory compared to standard MIMO imaging radars. Additionally, observing the scenery from both monostatic and bistatic perspectives with large bistatic angles can further increase the information content of radar images, as different parts of complex targets can exhibit different scattering mechanisms. Both technologies, synthetic aperture radar and coherent multistatic radar networks, come with demanding system requirements regarding the localization and synchronization of the involved radars, which are addressed by the proposed approach. The unique aspect of our novel bi-/multistatic radar approach is that no auxiliary sensor technology is needed to determine the trajectory. The same radar signals are jointly used at the same time for trajectory determination, clock synchronization, and bistatic SAR imaging. The integrated self-contained trajectory estimation is based on a particle filter algorithm that processes the line-of-sight radar signals of the bistatic radar pairs, which are exchanged in a double-sided two-way ranging manner. This approach opens up new applications of bi-/multistatic radar for autonomous air and ground vehicles. However, the requirement of a line-of-sight connection between the radar pairs imposes a constraint on possible bistatic constellations and trajectories. Therefore, it is shown that suitable compromises regarding the geometry, localization accuracy, and resolution of SAR imaging must also be taken into account. We demonstrate the capabilities of this approach by generating monostatic and bistatic SAR images with 77 GHz SIMO FMCW radar sensors from indoor and outdoor measurement scenarios with synthetically generated apertures estimated by the integrated self-contained localization algorithm.
与标准MIMO成像雷达相比，通过沿着雷达传感器的轨迹创建合成孔径，可以显著提高雷达成像性能。此外，由于复杂目标的不同部位会表现出不同的散射机制，采用大的双基地角度对景物进行单基地和双基地观测，可以进一步增加雷达图像的信息量。这两种技术，合成孔径雷达和相干多基地雷达网络，都对所涉及雷达的定位和同步提出了苛刻的系统要求，所提出的方法解决了这一问题。我们的新型双/多基地雷达方法的独特之处在于不需要辅助传感器技术来确定轨迹。同时使用相同的雷达信号进行弹道确定、时钟同步和双基地SAR成像。综合自包含轨迹估计基于粒子滤波算法，该算法对双基地雷达对的视距雷达信号进行处理，以双面双向测距方式交换。这种方法为自主空中和地面车辆的双/多基地雷达开辟了新的应用。然而，雷达对之间的视距连接要求对可能的双基地星座和轨迹施加了限制。因此，还必须考虑到SAR成像的几何形状，定位精度和分辨率的适当折衷。我们通过使用77 GHz SIMO FMCW雷达传感器从室内和室外测量场景中生成单站和双站SAR图像，并通过集成的自包含定位算法估计合成生成的孔径，证明了该方法的能力。
{"title":"Integrated Self-Contained Trajectory Estimation and Multistatic SAR Imaging in a Non-Static Uncoupled Bistatic Radar Network","authors":"Patrick Fenske;Tobias Koegel;Roghayeh Ghasemi;Danielle Gunders-Hunt;Martin Vossiek","doi":"10.1109/JMW.2025.3554050","DOIUrl":"https://doi.org/10.1109/JMW.2025.3554050","url":null,"abstract":"Radar imaging performance can be significantly improved by creating synthetic apertures along a radar sensor's trajectory compared to standard MIMO imaging radars. Additionally, observing the scenery from both monostatic and bistatic perspectives with large bistatic angles can further increase the information content of radar images, as different parts of complex targets can exhibit different scattering mechanisms. Both technologies, synthetic aperture radar and coherent multistatic radar networks, come with demanding system requirements regarding the localization and synchronization of the involved radars, which are addressed by the proposed approach. The unique aspect of our novel bi-/multistatic radar approach is that no auxiliary sensor technology is needed to determine the trajectory. The same radar signals are jointly used at the same time for trajectory determination, clock synchronization, and bistatic SAR imaging. The integrated self-contained trajectory estimation is based on a particle filter algorithm that processes the line-of-sight radar signals of the bistatic radar pairs, which are exchanged in a double-sided two-way ranging manner. This approach opens up new applications of bi-/multistatic radar for autonomous air and ground vehicles. However, the requirement of a line-of-sight connection between the radar pairs imposes a constraint on possible bistatic constellations and trajectories. Therefore, it is shown that suitable compromises regarding the geometry, localization accuracy, and resolution of SAR imaging must also be taken into account. We demonstrate the capabilities of this approach by generating monostatic and bistatic SAR images with 77 GHz SIMO FMCW radar sensors from indoor and outdoor measurement scenarios with synthetically generated apertures estimated by the integrated self-contained localization algorithm.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"600-615"},"PeriodicalIF":6.9,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10965474","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925042","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}
Pub Date : 2025-04-11DOI: 10.1109/JMW.2025.3550087
David H. Gultekin;John T. Vaughan;Devashish Shrivastava
Time-varying radiofrequency (RF) fields necessary to perform magnetic resonance imaging (MRI) may induce excessive heating near implanted conductive medical devices during MRI. The time and space-averaged root-mean-square effective magnetic field (B1+rms) and specific absorption rate (SAR) have been proposed as metrics to control the RF-induced heating and avoid unintended thermal injury. We experimentally evaluate the relationship between the RF-induced heating near an implanted conductive medical device, scanner-reported B1+rms, and RF power. RF heating was measured near the electrodes of a commercial deep brain stimulation (DBS) lead placed in a tissue-equivalent gel phantom using fluoroptic temperature probes in a commercial 3T scanner during MRI. Four RF transmit/receive coil combinations were used: a circularly polarized head transmit/receive coil, a 20-channel head/neck, a 32-channel head, or a 64-channel head/neck receive-only coil with a whole-body transmit coil. RF heating was induced by a 2D GRE sequence using two RF pulse types (fast and normal), three flip angles (30°, 60°, and 90°), and turning the receive-only coils off/on. The scanner-reported B1+rms and RF power were recorded. Measurements show that temperature change correlates linearly with both RF power and square of B1+rms for each coil and combination. However, the variation in heating for various RF coils and combinations was much larger for B1+rms compared to RF power. Additional studies across other MR scanners are needed to better understand the extent of variation in RF-induced heating near implanted conductive devices as a function of scanner-reported B1+rms and RF power to develop conservative and reliable patient labeling.
{"title":"Experimental Evaluation of Relationship Between Radiofrequency Heating Near Implanted Conductive Devices, Scanner-Reported B1+rms, and Transmit Power","authors":"David H. Gultekin;John T. Vaughan;Devashish Shrivastava","doi":"10.1109/JMW.2025.3550087","DOIUrl":"https://doi.org/10.1109/JMW.2025.3550087","url":null,"abstract":"Time-varying radiofrequency (RF) fields necessary to perform magnetic resonance imaging (MRI) may induce excessive heating near implanted conductive medical devices during MRI. The time and space-averaged root-mean-square effective magnetic field (B<sub>1+rms</sub>) and specific absorption rate (SAR) have been proposed as metrics to control the RF-induced heating and avoid unintended thermal injury. We experimentally evaluate the relationship between the RF-induced heating near an implanted conductive medical device, scanner-reported B<sub>1+rms</sub>, and RF power. RF heating was measured near the electrodes of a commercial deep brain stimulation (DBS) lead placed in a tissue-equivalent gel phantom using fluoroptic temperature probes in a commercial 3T scanner during MRI. Four RF transmit/receive coil combinations were used: a circularly polarized head transmit/receive coil, a 20-channel head/neck, a 32-channel head, or a 64-channel head/neck receive-only coil with a whole-body transmit coil. RF heating was induced by a 2D GRE sequence using two RF pulse types (fast and normal), three flip angles (30°, 60°, and 90°), and turning the receive-only coils off/on. The scanner-reported B<sub>1+rms</sub> and RF power were recorded. Measurements show that temperature change correlates linearly with both RF power and square of B<sub>1+rms</sub> for each coil and combination. However, the variation in heating for various RF coils and combinations was much larger for B<sub>1+rms</sub> compared to RF power. Additional studies across other MR scanners are needed to better understand the extent of variation in RF-induced heating near implanted conductive devices as a function of scanner-reported B<sub>1+rms</sub> and RF power to develop conservative and reliable patient labeling.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"518-525"},"PeriodicalIF":6.9,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10963882","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925335","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}
The THz gap has been a significant research objective for photonics and electronics for decades. This work introduces a fully integrated frequency modulated continuous wave (FMCW) radar sensor with a center frequency of 0.48 THz, realized in a silicon-germanium (SiGe) technology. The sensor consists of a THz MMIC integrated onto a front-end printed circuit board (PCB) with FR4 substrate used for frequency synthesis and IF signal amplification. A dielectric polytetrafluoroethylene (PTFE) lens is mounted above the MMIC to act as transmitter (Tx) and receiver (Rx) lens as well as a physical protection for the bond wires of the MMIC. A back-end PCB generates the supply voltages and control signals, and its analog-digital-converter (ADC) samples the IF signal. The whole sensor is just 4.9 cm by 4.3 cm in size and is cost-efficient due to its design with FR4 PCBs. The MMIC reaches an output power of up to $-9$ dBm. In FMCW operation with the full sensor, a tuning range of 49 GHz is reached along an equivalent isotropic radiated power (EIRP) of up to 22 dBm. Distance measurements were successfully tested for distances of up to 5 m, and a radiation pattern is presented. In summary, this article demonstrates the potential of SiGe technology in the THz range for applications like localization, material characterization, and communication.
{"title":"A Fully Integrated 0.48 THz FMCW Radar Sensor in a SiGe Technology","authors":"Florian Vogelsang;Jonathan Bott;David Starke;Marc Hamme;Benedikt Sievert;Holger Rücker;Nils Pohl","doi":"10.1109/JMW.2025.3553681","DOIUrl":"https://doi.org/10.1109/JMW.2025.3553681","url":null,"abstract":"The THz gap has been a significant research objective for photonics and electronics for decades. This work introduces a fully integrated frequency modulated continuous wave (FMCW) radar sensor with a center frequency of 0.48 THz, realized in a silicon-germanium (SiGe) technology. The sensor consists of a THz MMIC integrated onto a front-end printed circuit board (PCB) with FR4 substrate used for frequency synthesis and IF signal amplification. A dielectric polytetrafluoroethylene (PTFE) lens is mounted above the MMIC to act as transmitter (Tx) and receiver (Rx) lens as well as a physical protection for the bond wires of the MMIC. A back-end PCB generates the supply voltages and control signals, and its analog-digital-converter (ADC) samples the IF signal. The whole sensor is just 4.9 cm by 4.3 cm in size and is cost-efficient due to its design with FR4 PCBs. The MMIC reaches an output power of up to <inline-formula><tex-math>$-9$</tex-math></inline-formula> dBm. In FMCW operation with the full sensor, a tuning range of 49 GHz is reached along an equivalent isotropic radiated power (EIRP) of up to 22 dBm. Distance measurements were successfully tested for distances of up to 5 m, and a radiation pattern is presented. In summary, this article demonstrates the potential of SiGe technology in the THz range for applications like localization, material characterization, and communication.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"572-582"},"PeriodicalIF":6.9,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10959113","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925222","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}
Pub Date : 2025-04-04DOI: 10.1109/JMW.2025.3553507
Yuewen Zhou;Fangzheng Zhang;Jiayuan Kong;Yihan Wang;Jinhu Li;Kunyang Chen;Guanqun Sun;Yuhui He;Shilong Pan
Cluster target detection is challenging for traditional narrow-band radars. Microwave photonic multiple-input-multiple-output (MIMO) radar is an emerging technique for accurate cluster target detection, which enhances range and angular resolution via its large bandwidth and virtual aperture. Previous research on microwave photonic MIMO radars focuses on the effectiveness of photonics-based hardware, while its advantages for practical applications have not been effectively validated. This paper demonstrates a field trial of cluster target detection by a broadband microwave photonic MIMO radar having an 8×8 MIMO array and a bandwidth of 8 GHz per channel. Using a broadband digital beamforming algorithm that compensates for aperture fill time, precise target detection is achieved without beam squint and broadening problems. Meanwhile, grating lobes due to sparse array are well suppressed, which enables the improvement of angular resolution by using large-aperture sparse array. In the experiment, detections of a single drone and three densely distributed drones as a cluster are implemented respectively. By comparing the results of 50-MHz narrowband MIMO detection and 8-GHz full-band MIMO detection, the advantage of broadband microwave photonic MIMO radar is verified. For single drone detection, the range resolution and angular resolution are estimated to be 2.1 cm and 0.17°, respectively, and the grating lobes are well suppressed with peak-to-maximum grating-lobe ratio over 13.5 dB. When detecting three drones as a cluster, the individuals are precisely distinguished and located. The results validate that the microwave photonic MIMO radar has high-resolution detection capability superior to traditional narrow-band radars, and it provides an effective and practical solution for cluster target detection.
{"title":"Field Trial of Cluster Target Detection by Broadband Microwave Photonic MIMO Radar","authors":"Yuewen Zhou;Fangzheng Zhang;Jiayuan Kong;Yihan Wang;Jinhu Li;Kunyang Chen;Guanqun Sun;Yuhui He;Shilong Pan","doi":"10.1109/JMW.2025.3553507","DOIUrl":"https://doi.org/10.1109/JMW.2025.3553507","url":null,"abstract":"Cluster target detection is challenging for traditional narrow-band radars. Microwave photonic multiple-input-multiple-output (MIMO) radar is an emerging technique for accurate cluster target detection, which enhances range and angular resolution via its large bandwidth and virtual aperture. Previous research on microwave photonic MIMO radars focuses on the effectiveness of photonics-based hardware, while its advantages for practical applications have not been effectively validated. This paper demonstrates a field trial of cluster target detection by a broadband microwave photonic MIMO radar having an 8×8 MIMO array and a bandwidth of 8 GHz per channel. Using a broadband digital beamforming algorithm that compensates for aperture fill time, precise target detection is achieved without beam squint and broadening problems. Meanwhile, grating lobes due to sparse array are well suppressed, which enables the improvement of angular resolution by using large-aperture sparse array. In the experiment, detections of a single drone and three densely distributed drones as a cluster are implemented respectively. By comparing the results of 50-MHz narrowband MIMO detection and 8-GHz full-band MIMO detection, the advantage of broadband microwave photonic MIMO radar is verified. For single drone detection, the range resolution and angular resolution are estimated to be 2.1 cm and 0.17°, respectively, and the grating lobes are well suppressed with peak-to-maximum grating-lobe ratio over 13.5 dB. When detecting three drones as a cluster, the individuals are precisely distinguished and located. The results validate that the microwave photonic MIMO radar has high-resolution detection capability superior to traditional narrow-band radars, and it provides an effective and practical solution for cluster target detection.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"631-639"},"PeriodicalIF":6.9,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10949595","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925266","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}
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