Pub Date : 2026-01-08DOI: 10.1016/j.aeue.2026.156206
Zheng You, Jinqi Zhang, Xuyin Niu, Guangqian Wu, Shaofeng Wang
A flexible wideband circularly polarized (CP) antenna with low radar cross section (RCS) is proposed. It employs a double-layer polarization conversion metasurface (PCM) integrated with a phase control surface (PCS). The metasurface units are orthogonally arranged to form a checkerboard patterned metasurface, which is integrated with a slot antenna array fed by a sequential rotating power divider network with a 90° phase difference. The feed network is fabricated on the flexible printed circuit (FPC). The CP antenna achieves a 3 dB axial ratio (AR) bandwidth from 6.72 GHz to 9.06 GHz and provides over 10 dB radar cross section (RCS) reduction across 5.82 GHz to 19.85 GHz. Under central bending angle from 0° to 90° conditions, the proposed antenna maintains stable RCS reduction and radiation performance, while also suppressing RCS for oblique incident electromagnetic waves within elevation angles from 0° to 45°. The designed metasurface antenna is suitable for radar detection systems and wearable devices.
{"title":"Wideband RCS reduction of circularly polarized flexible antenna using polarization conversion metasurface","authors":"Zheng You, Jinqi Zhang, Xuyin Niu, Guangqian Wu, Shaofeng Wang","doi":"10.1016/j.aeue.2026.156206","DOIUrl":"10.1016/j.aeue.2026.156206","url":null,"abstract":"<div><div>A flexible wideband circularly polarized (CP) antenna with low radar cross section (RCS) is proposed. It employs a double-layer polarization conversion metasurface (PCM) integrated with a phase control surface (PCS). The metasurface units are orthogonally arranged to form a checkerboard patterned metasurface, which is integrated with a slot antenna array fed by a sequential rotating power divider network with a 90° phase difference. The feed network is fabricated on the flexible printed circuit (FPC). The CP antenna achieves a 3 dB axial ratio (AR) bandwidth from 6.72 GHz to 9.06 GHz and provides over 10 dB radar cross section (RCS) reduction across 5.82 GHz to 19.85 GHz. Under central bending angle from 0° to 90° conditions, the proposed antenna maintains stable RCS reduction and radiation performance, while also suppressing RCS for oblique incident electromagnetic waves within elevation angles from 0° to 45°. The designed metasurface antenna is suitable for radar detection systems and wearable devices.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156206"},"PeriodicalIF":3.2,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-08DOI: 10.1016/j.aeue.2026.156207
Da Huang, Ming Bai
A partitioned iterative method is proposed for the scattering analysis of thin-walled PEC cavities under plane wave excitation. The method decomposes the excitation into internal and external components separated by the cavity aperture, enabling independent iterative calculations of induced currents on the inner and outer cavity walls. Iterative calculations for the induced currents in both parts are independent, and total scattered fields are synthesized from both parts. This partitioned iterative method is particularly applicable to solving bistatic scattering problems, achieving higher accuracy compared with the Iterative Physical Optics (IPO) method and Physical Optics (PO) in the case of cavity and duct models. Numerical results validate the accuracy of the method and the necessity of employing the partitioned iterative strategy.
{"title":"A partitioned iterative method for bistatic scattering analysis of PEC cavities with internal–external incident field decomposition","authors":"Da Huang, Ming Bai","doi":"10.1016/j.aeue.2026.156207","DOIUrl":"10.1016/j.aeue.2026.156207","url":null,"abstract":"<div><div>A partitioned iterative method is proposed for the scattering analysis of thin-walled PEC cavities under plane wave excitation. The method decomposes the excitation into internal and external components separated by the cavity aperture, enabling independent iterative calculations of induced currents on the inner and outer cavity walls. Iterative calculations for the induced currents in both parts are independent, and total scattered fields are synthesized from both parts. This partitioned iterative method is particularly applicable to solving bistatic scattering problems, achieving higher accuracy compared with the Iterative Physical Optics (IPO) method and Physical Optics (PO) in the case of cavity and duct models. Numerical results validate the accuracy of the method and the necessity of employing the partitioned iterative strategy.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156207"},"PeriodicalIF":3.2,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-07DOI: 10.1016/j.aeue.2025.156192
Girdhari Chaudhary , Yongchae Jeong
This paper presents RF co-design approach for a multi-function filtering phase shifter that integrate functionalities of a tunable bandpass filter, continuously tunable phase shifter, and isolator into a single circuit. To support detailed design, the analytical spectral S-parameters of the proposed multi-function non-reciprocal filtering phase shifter have been derived. The isolator functionality (i.e. |S21| ≠ |S12|) can be achieved using time-varying capacitors modulated by progressive phase shift sinusoidal signal. The frequency and transmission phase can be simultaneously tuned by varying resonant frequency of resonators. For experimental validation, a microstrip line multi-function non-reciprocal filtering phase shifter is designed, fabricated and measured. The measurement demonstrates a phase shift range of 200o with forward insertion loss less than 4.9 dB and reverse isolation higher than 30 dB across all phase shift and frequency tuning states. The passband frequency is tuned from 1.42 GHz to 1.75 GHz, providing frequency tunability range of 330 MHz (i.e. tuning ratio: 1:1.2324), while maintaining phase shift range of 200o at each frequency tuning state. Furthermore, the measured input and output return losses are higher than 12 dB for each phase shift and passband frequency tuning states.
{"title":"Spatiotemporal modulated multi-functional Non-reciprocal filtering phase shifter with continuously tunable frequency and isolator functionalities","authors":"Girdhari Chaudhary , Yongchae Jeong","doi":"10.1016/j.aeue.2025.156192","DOIUrl":"10.1016/j.aeue.2025.156192","url":null,"abstract":"<div><div>This paper presents RF co-design approach for a multi-function filtering phase shifter that integrate functionalities of a tunable bandpass filter, continuously tunable phase shifter, and isolator into a single circuit. To support detailed design, the analytical spectral S-parameters of the proposed multi-function non-reciprocal filtering phase shifter have been derived. The isolator functionality (<em>i.e.</em> |S<sub>21</sub>| ≠ |S<sub>12</sub>|) can be achieved using time-varying capacitors modulated by progressive phase shift sinusoidal signal. The frequency and transmission phase can be simultaneously tuned by varying resonant frequency of resonators. For experimental validation, a microstrip line multi-function non-reciprocal filtering phase shifter is designed, fabricated and measured. The measurement demonstrates a phase shift range of 200<sup>o</sup> with forward insertion loss less than 4.9 dB and reverse isolation higher than 30 dB across all phase shift and frequency tuning states. The passband frequency is tuned from 1.42 GHz to 1.75 GHz, providing frequency tunability range of 330 MHz (<em>i.e.</em> tuning ratio: 1:1.2324), while maintaining phase shift range of 200<sup>o</sup> at each frequency tuning state. Furthermore, the measured input and output return losses are higher than 12 dB for each phase shift and passband frequency tuning states.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156192"},"PeriodicalIF":3.2,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.aeue.2025.156193
Slawomir Koziel , Kaustab C. Sahu , Anna Pietrenko-Dabrowska
Full-wave electromagnetic (EM) analysis is commonly used in microwave engineering. Nonetheless, EM-driven design involves considerable expenses. Surrogate modeling may mitigate this issue; however, constructing reliable metamodels is demanding due to the curse of dimensionality and design utility requirements. This paper introduces a novel data-driven modeling methodology that integrates an attention mechanism into Recurrent Neural Networks (RNNs) based on Long Short-Term Memory (LSTM) and Gated Recurrent Units (GRU). The proposed surrogate enhances the representation of sequential dependencies across the frequency range in S-parameter estimation, treating frequency responses as time-series data. The projected LSTM and GRU layers reduce the dimensionality of the hidden states through a learned projection matrix, which reduces computational complexity and enhances the capacity of the model to capture long-term dependencies. Another enhancement is the attention mechanism, which dynamically assigns greater importance to critical frequency regions and enables the model to selectively highlight the most relevant components (e.g., corresponding to the circuit's center frequencies). The predictive power is further improved by sensitivity-based dimensionality reduction. Comprehensive verification showcases the competitive performance of our technique regarding predictive power as compared to multiple benchmark methods.
{"title":"Behavioral modeling of microwave components in constrained domains using recurrent neural networks with attention layers","authors":"Slawomir Koziel , Kaustab C. Sahu , Anna Pietrenko-Dabrowska","doi":"10.1016/j.aeue.2025.156193","DOIUrl":"10.1016/j.aeue.2025.156193","url":null,"abstract":"<div><div>Full-wave electromagnetic (EM) analysis is commonly used in microwave engineering. Nonetheless, EM-driven design involves considerable expenses. Surrogate modeling may mitigate this issue; however, constructing reliable metamodels is demanding due to the curse of dimensionality and design utility requirements. This paper introduces a novel data-driven modeling methodology that integrates an attention mechanism into Recurrent Neural Networks (RNNs) based on Long Short-Term Memory (LSTM) and Gated Recurrent Units (GRU). The proposed surrogate enhances the representation of sequential dependencies across the frequency range in S-parameter estimation, treating frequency responses as time-series data. The projected LSTM and GRU layers reduce the dimensionality of the hidden states through a learned projection matrix, which reduces computational complexity and enhances the capacity of the model to capture long-term dependencies. Another enhancement is the attention mechanism, which dynamically assigns greater importance to critical frequency regions and enables the model to selectively highlight the most relevant components (e.g., corresponding to the circuit's center frequencies). The predictive power is further improved by sensitivity-based dimensionality reduction. Comprehensive verification showcases the competitive performance of our technique regarding predictive power as compared to multiple benchmark methods.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156193"},"PeriodicalIF":3.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.aeue.2026.156198
Davut Ertekin , Mustafa Özden
The demand for green energy and application of hydrogen or photovoltaic (PV) for electrical vehicles (EVs) are enhancing steadily each day. DC–DC converters are critical power conversion systems that regulate voltage and current levels for battery packs in electric vehicles (EVs) powered by fuel cells (FCs) or PV panels and set the voltage for electric motor through an inverter circuit. The longevity of renewable energy sources (RESs) such as the FCs and PV arrays is heavily influenced by the current drawn by the DC–DC converter. Additionally, the converter topology must be cost-effective, minimize voltage and current stresses on semiconductor devices, offer ease of control, and provide flexible voltage outputs to meet the dynamic demands of the battery pack. This study introduces a switching DC–DC power converter designed specifically for FC-based electric vehicles (FCEVs), controlled by an innovative adaptive neuro fuzzy controller (ANFC). The high gain of the proposed converter enables the energy obtained from FCs and PV cells to be stored in a high-voltage battery pack and subsequently used to drive the electric motor and other electric vehicle components (such as lighting, heating, or cooling). This implies that, in an electric vehicle, it is sufficient to use only the proposed power converter instead of employing separate DC–DC converters for different energy sources such as PV or FCs. Subsequently, the stored energy can be used to operate the motor by providing the input voltage to the inverter. This approach makes the overall system more efficient and cost-effective. At the end of the simulation studies, it was observed that the proposed controller successfully ensures the control of the DC–DC converter, that no overshoot or oscillation occurs at the converter output, that an extremely short settling time of 0.016 s is achieved, and that a very low steady-state error of 0.7 is obtained. Experimental results for the proposed power converter are presented, thereby validating the theoretical findings.
{"title":"Adaptive neuro fuzzy control of a high gain bidirectional power converter for photovoltaic-hydrogen renewable electric vehicles with enhanced lifespan and reliability","authors":"Davut Ertekin , Mustafa Özden","doi":"10.1016/j.aeue.2026.156198","DOIUrl":"10.1016/j.aeue.2026.156198","url":null,"abstract":"<div><div>The demand for green energy and application of hydrogen or photovoltaic (PV) for electrical vehicles (EVs) are enhancing steadily each day. DC–DC converters are critical power conversion systems that regulate voltage and current levels for battery packs in electric vehicles (EVs) powered by fuel cells (FCs) or PV panels and set the voltage for electric motor through an inverter circuit. The longevity of renewable energy sources (RESs) such as the FCs and PV arrays is heavily influenced by the current drawn by the DC–DC converter. Additionally, the converter topology must be cost-effective, minimize voltage and current stresses on semiconductor devices, offer ease of control, and provide flexible voltage outputs to meet the dynamic demands of the battery pack. This study introduces a switching DC–DC power converter designed specifically for FC-based electric vehicles (FCEVs), controlled by an innovative adaptive neuro fuzzy controller (ANFC). The high gain of the proposed converter enables the energy obtained from FCs and PV cells to be stored in a high-voltage battery pack and subsequently used to drive the electric motor and other electric vehicle components (such as lighting, heating, or cooling). This implies that, in an electric vehicle, it is sufficient to use only the proposed power converter instead of employing separate DC–DC converters for different energy sources such as PV or FCs. Subsequently, the stored energy can be used to operate the motor by providing the input voltage to the inverter. This approach makes the overall system more efficient and cost-effective. At the end of the simulation studies, it was observed that the proposed controller successfully ensures the control of the DC–DC converter, that no overshoot or oscillation occurs at the converter output, that an extremely short settling time of 0.016 s is achieved, and that a very low steady-state error of 0.7 is obtained. Experimental results for the proposed power converter are presented, thereby validating the theoretical findings.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156198"},"PeriodicalIF":3.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.aeue.2025.156194
Basma Nazar, Sarab Kamal Mahmood, Noor Aldeen Hamza
Employing a Reconfigurable Intelligent Surface (RIS) in indoor environments is a promising technology for enhancing the quality of communication among multiple Internet of Things (IoT) devices, particularly when barriers within structures obstruct direct pathways between network components and the receiving end. Selecting the optimal placement for installing the RIS within a building profoundly influences transmission quality and network coverage, particularly when devices are situated at considerable distances or have to pass several obstacles before their signal reaches the receiver. In this paper, we propose three distinct approaches to determining the optimal site for the RIS, which will be installed on the ceiling of the building. This ensures comprehensive coverage for all network components transmitting data to the Base Station (BS) in uplink mode via Wi-Fi. All three methods depend on calculating the percentile of the lowest Signal-to-Noise ratio (SNR) values for IoT devices by utilizing the Hyndman-Fan Type 7 approach and the balance paths losses for the second and third methods to find the optimal site for the RIS surface. Additionally, our research's propagation model utilizes the Motley-Keenan model to determine route losses. Also, the RIS's losses, encompassing phase quantization and orientation losses, are considered in its total gain. A two-stage search methodology, including a coarse search succeeded by a fine search, was employed to ascertain the optimal location for the RIS. Furthermore, in this research, we employed two geometric representations of the indoor environment: the two-dimensional (2D) and three-dimensional (3D) representations, in addition to two different modulation schemes (QPSK and 16QAM) for each method.The present research also presumes perfect large-scale channel state information (CSI) for the IoT-RIS and RIS-BS connections, as well as a static indoor layout with fixed locations of IoT devices and obstructions. Finally, the maximum (SNR) of 5 % was recorded at the designated locations, coverage was assessed during the fine search phase, and the performance measurements at the designated sites and the final RIS location for each approach across many parameters are presented in tables and figures in addition to calculate the complexity of this proposed methods.
在室内环境中采用可重构智能表面（RIS）是一种很有前途的技术，可以提高多个物联网（IoT）设备之间的通信质量，特别是当结构内的障碍阻碍了网络组件和接收端之间的直接路径时。在建筑物内选择安装RIS的最佳位置会对传输质量和网络覆盖产生深远的影响，特别是当设备位于相当远的距离或在信号到达接收器之前必须通过几个障碍物时。在本文中，我们提出了三种不同的方法来确定RIS的最佳位置，RIS将安装在建筑物的天花板上。这确保了通过Wi-Fi以上行模式向基站（BS）传输数据的所有网络组件的全面覆盖。所有三种方法都依赖于利用Hyndman-Fan Type 7方法计算物联网设备最低信噪比（SNR）值的第5个百分位数，以及第二和第三种方法的平衡路径损失，以找到RIS表面的最佳位置。此外，我们研究的传播模型利用莫特利-基南模型来确定路由损失。此外，RIS的损耗，包括相位量化和定向损耗，在其总增益中被考虑。采用两阶段搜索方法，包括粗搜索和细搜索，确定RIS的最佳位置。此外，在本研究中，我们采用了室内环境的两种几何表示：二维（2D）和三维（3D）表示，以及两种不同的调制方案（QPSK和16QAM）。本研究还假设了物联网- ris和RIS-BS连接的完美大规模信道状态信息（CSI），以及物联网设备和障碍物固定位置的静态室内布局。最后，在指定地点记录了5%的最大信噪比，在精细搜索阶段评估了覆盖范围，并在表格和图表中给出了指定地点的性能测量结果和每种方法在许多参数下的最终RIS位置，此外还计算了所提出方法的复杂性。
{"title":"Improving an Indoor RIS Surface Location via the Motley-Keenan Model and a Two-Stage Grid Search Algorithm","authors":"Basma Nazar, Sarab Kamal Mahmood, Noor Aldeen Hamza","doi":"10.1016/j.aeue.2025.156194","DOIUrl":"10.1016/j.aeue.2025.156194","url":null,"abstract":"<div><div>Employing a Reconfigurable Intelligent Surface (RIS) in indoor environments is a promising technology for enhancing the quality of communication among multiple Internet of Things (IoT) devices, particularly when barriers within structures obstruct direct pathways between network components and the receiving end. Selecting the optimal placement for installing the RIS within a building profoundly influences transmission quality and network coverage, particularly when devices are situated at considerable distances or have to pass several obstacles before their signal reaches the receiver. In this paper, we propose three distinct approaches to determining the optimal site for the RIS, which will be installed on the ceiling of the building. This ensures comprehensive coverage for all network components transmitting data to the Base Station (BS) in uplink mode via Wi-Fi. All three methods depend on calculating the <span><math><msup><mn>5</mn><mi>th</mi></msup></math></span> percentile of the lowest Signal-to-Noise ratio (SNR) values for IoT devices by utilizing the Hyndman-Fan Type 7 approach and the balance paths losses for the second and third methods to find the optimal site for the RIS surface. Additionally, our research's propagation model utilizes the Motley-Keenan model to determine route losses. Also, the RIS's losses, encompassing phase quantization and orientation losses, are considered in its total gain. A two-stage search methodology, including a coarse search succeeded by a fine search, was employed to ascertain the optimal location for the RIS. Furthermore, in this research, we employed two geometric representations of the indoor environment: the two-dimensional (2D) and three-dimensional (3D) representations, in addition to two different modulation schemes (QPSK and 16QAM) for each method.The present research also presumes perfect large-scale channel state information (CSI) for the IoT-RIS and RIS-BS connections, as well as a static indoor layout with fixed locations of IoT devices and obstructions. Finally, the maximum (SNR) of 5 % was recorded at the designated locations, coverage was assessed during the fine search phase, and the performance measurements at the designated sites and the final RIS location for each approach across many parameters are presented in tables and figures in addition to calculate the complexity of this proposed methods.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156194"},"PeriodicalIF":3.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.aeue.2026.156197
Gongda Hu , Yukun Fang , Dawei Ding
In this article, a novel 2-bit fragment-type structure (FTS) design technique is proposed for automated design of microstrip bandpass filters (BPFs) of flexible structure and irregular shape. The 2-bit FTS description includes subtle structures in FTS elements on PCBs, which increase the dynamic range of equivalent reactance compared with 1-bit FTS without yielding large design matrix for BPF structure characterization. Structural coding method for 2-bit FTS with necessary vias is proposed, and multi-objective optimization search scheme for the FTS-based high performance BPF is illustrated. For demonstration, two compact planar BPFs with sharp roll-off are designed for operation at f0 = 1.75 GHz. The one with irregular design area presents a measured 3-dB passband of 32.1 %, in-band return loss (RL) of over 23 dB, and suppression of at least 20 dB in the stopband up to 2.1 f0. The mechanism of provoking multiple transmission zeros with 2-bit FTS are explained and performance comparison is conducted.
{"title":"Automated design of irregularly shaped microstrip bandpass filters with 2-bit fragment-type structure","authors":"Gongda Hu , Yukun Fang , Dawei Ding","doi":"10.1016/j.aeue.2026.156197","DOIUrl":"10.1016/j.aeue.2026.156197","url":null,"abstract":"<div><div>In this article, a novel 2-bit fragment-type structure (FTS) design technique is proposed for automated design of microstrip bandpass filters (BPFs) of flexible structure and irregular shape. The 2-bit FTS description includes subtle structures in FTS elements on PCBs, which increase the dynamic range of equivalent reactance compared with 1-bit FTS without yielding large design matrix for BPF structure characterization. Structural coding method for 2-bit FTS with necessary vias is proposed, and multi-objective optimization search scheme for the FTS-based high performance BPF is illustrated. For demonstration, two compact planar BPFs with sharp roll-off are designed for operation at <em>f</em><sub>0</sub> = 1.75 GHz. The one with irregular design area presents a measured 3-dB passband of 32.1 %, in-band return loss (RL) of over 23 dB, and suppression of at least 20 dB in the stopband up to 2.1 <em>f</em><sub>0</sub>. The mechanism of provoking multiple transmission zeros with 2-bit FTS are explained and performance comparison is conducted.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156197"},"PeriodicalIF":3.2,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-04DOI: 10.1016/j.aeue.2026.156195
Feifei Yang , Jia He , Xinlin Song , Huiping Yin , Jiangxing Chen
The dynamic characteristics of nonlinear circuits can be significantly enriched by the introduction of memristors. However, most existing memristor-based nonlinear circuits rely on inductive components, which limit the potential of memristor-based nonlinear circuits for miniaturization and on-chip implementation. Therefore, a memristor-based nonlinear circuit without inductor can overcome these limitations. In this work, a dual-memristor nonlinear circuit without inductor is designed, and then the dynamical equation of the dual-memristor nonlinear circuit and the corresponding energy function are obtained by using Kirchhoff's laws and Helmholtz's theorems. Furthermore, a novel hyperchaotic map is established from the dynamical equations of the dual-memristor nonlinear circuit by linearly transforming the state equations. Phase portraits, complexity measures, Lyapunov exponents, and bifurcation diagrams are employed to comprehensively analyze the complex dynamical behaviors of the proposed map. The results demonstrate that the map exhibits rich dynamical phenomena, such as periodic, chaotic, and hyperchaotic regimes. This work offers a valuable framework for applications in secure communication and pseudo-random number generation that require complex, high-dimensional chaotic dynamics. In addition, the elimination of the inductor not only makes the circuit model more amenable to very large-scale integration implementation but also provides a new and efficient discrete-time model for theoretical research in hyperchaos.
{"title":"Modeling and dynamical Behaviors of a hyperchaotic map based on dual-memristor circuit without inductor","authors":"Feifei Yang , Jia He , Xinlin Song , Huiping Yin , Jiangxing Chen","doi":"10.1016/j.aeue.2026.156195","DOIUrl":"10.1016/j.aeue.2026.156195","url":null,"abstract":"<div><div>The dynamic characteristics of nonlinear circuits can be significantly enriched by the introduction of memristors. However, most existing memristor-based nonlinear circuits rely on inductive components, which limit the potential of memristor-based nonlinear circuits for miniaturization and on-chip implementation. Therefore, a memristor-based nonlinear circuit without inductor can overcome these limitations. In this work, a dual-memristor nonlinear circuit without inductor is designed, and then the dynamical equation of the dual-memristor nonlinear circuit and the corresponding energy function are obtained by using Kirchhoff's laws and Helmholtz's theorems. Furthermore, a novel hyperchaotic map is established from the dynamical equations of the dual-memristor nonlinear circuit by linearly transforming the state equations. Phase portraits, complexity measures, Lyapunov exponents, and bifurcation diagrams are employed to comprehensively analyze the complex dynamical behaviors of the proposed map. The results demonstrate that the map exhibits rich dynamical phenomena, such as periodic, chaotic, and hyperchaotic regimes. This work offers a valuable framework for applications in secure communication and pseudo-random number generation that require complex, high-dimensional chaotic dynamics. In addition, the elimination of the inductor not only makes the circuit model more amenable to very large-scale integration implementation but also provides a new and efficient discrete-time model for theoretical research in hyperchaos.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156195"},"PeriodicalIF":3.2,"publicationDate":"2026-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-30DOI: 10.1016/j.aeue.2025.156190
Ruchita Gupta, Bhawna Aggarwal, Maneesha Gupta
In this paper, a new synthetic transformer architecture is proposed using MOS-C-based gyrator configuration that emulates magnetic transformer behavior through active components. This proposed design integrates grounded and floating synthetic inductors realized using MOS-based gyrator, connected in a T-network configuration for compactness, electronic tunability and CMOS compatibility. Analytical modeling confirms the inductance equivalency, transformer functionality, and coupling coefficient formulation. The proposed design employs all grounded passive elements. Simulations using Cadence Virtuoso in 180 nm gpdk CMOS technology with BSIM3v3 transistor model validates the design, demonstrating low-voltage operation (0.7 V), low power consumption (1.746 mW), and operates up to 40 MHz. Furthermore, the synthetic transformer is applied in a double-tuned band-pass filter (DTBPF) circuit to assess real world viability. Performance metrics such as gain, phase, transient, and noise response are analyzed. The double-tuned band-pass filter exhibits an output RMS noise of 146.7 V. Additionally, the coupling coefficient exhibits a wide tunable range from 0.32 to 0.93, highlighting strong electronic controllability. The sturdiness of the design has been verified by PVT variations, and Monte Carlo simulations. The proposed synthetic transformer offers miniaturization, electronically tunable, low power consumption and minimized silicon area ( X ), making it suitable for system-on-a-chip applications.
{"title":"A new low-power electronically tunable MOS-C synthetic transformer with application in double-tuned band-pass filter","authors":"Ruchita Gupta, Bhawna Aggarwal, Maneesha Gupta","doi":"10.1016/j.aeue.2025.156190","DOIUrl":"10.1016/j.aeue.2025.156190","url":null,"abstract":"<div><div>In this paper, a new synthetic transformer architecture is proposed using MOS-C-based gyrator configuration that emulates magnetic transformer behavior through active components. This proposed design integrates grounded and floating synthetic inductors realized using MOS-based gyrator, connected in a T-network configuration for compactness, electronic tunability and CMOS compatibility. Analytical modeling confirms the inductance equivalency, transformer functionality, and coupling coefficient formulation. The proposed design employs all grounded passive elements. Simulations using Cadence Virtuoso in 180 nm gpdk CMOS technology with BSIM3v3 transistor model validates the design, demonstrating low-voltage operation (<span><math><mo>±</mo></math></span>0.7 V), low power consumption (1.746 mW), and operates up to 40 MHz. Furthermore, the synthetic transformer is applied in a double-tuned band-pass filter (DTBPF) circuit to assess real world viability. Performance metrics such as gain, phase, transient, and noise response are analyzed. The double-tuned band-pass filter exhibits an output RMS noise of 146.7 <span><math><mi>μ</mi></math></span>V. Additionally, the coupling coefficient exhibits a wide tunable range from 0.32 to 0.93, highlighting strong electronic controllability. The sturdiness of the design has been verified by PVT variations, and Monte Carlo simulations. The proposed synthetic transformer offers miniaturization, electronically tunable, low power consumption and minimized silicon area (<span><math><mrow><mn>53</mn><mo>.</mo><mn>02</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> X <span><math><mrow><mn>65</mn><mo>.</mo><mn>86</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>), making it suitable for system-on-a-chip applications.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156190"},"PeriodicalIF":3.2,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-30DOI: 10.1016/j.aeue.2025.156183
Xingming Fan, Yihao Chen, Xin Zhang
This study addresses the low efficiency and instability of magnetically coupled resonant wireless power transfer (MCR-WPT) systems caused by inter-coil coupling variations at low frequencies. We propose an approach using differentially compensated low-frequency electromagnetic metamaterials. Unlike conventional research that ignores the coupling effects between metamaterial elements, this paper first establishes an equivalent circuit model that incorporates the mutual inductance coupling between adjacent elements, revealing the underlying mechanism by which inter-element coupling causes the overall resonant frequency shift of the array. Furthermore, a differentiated compensation capacitor design strategy is proposed. By assigning different lumped capacitors to elements at different positions in the array, this effectively compensates for the variations in equivalent inductance caused by these coupling differences, thereby stabilizing the array resonant frequency at the target frequency of 85 kHz. Finite element simulations demonstrate that the composite metamaterial array achieves a relative permeability near −1 at the target frequency and significantly optimizes the system's magnetic field distribution. Experimental results demonstrate that, over a transmission distance of 5 to 25 cm, the introduction of this composite metamaterial improves the system's transmission efficiency from 19.8%–49.3% to 40.1%–73.9%. Moreover, even under lateral displacement of the receiving coil, the system retains high efficiency, highlighting its improved robustness against misalignment.
{"title":"Design and application of differentiated compensation metamaterials for wireless power transfer system","authors":"Xingming Fan, Yihao Chen, Xin Zhang","doi":"10.1016/j.aeue.2025.156183","DOIUrl":"10.1016/j.aeue.2025.156183","url":null,"abstract":"<div><div>This study addresses the low efficiency and instability of magnetically coupled resonant wireless power transfer (MCR-WPT) systems caused by inter-coil coupling variations at low frequencies. We propose an approach using differentially compensated low-frequency electromagnetic metamaterials. Unlike conventional research that ignores the coupling effects between metamaterial elements, this paper first establishes an equivalent circuit model that incorporates the mutual inductance coupling between adjacent elements, revealing the underlying mechanism by which inter-element coupling causes the overall resonant frequency shift of the array. Furthermore, a differentiated compensation capacitor design strategy is proposed. By assigning different lumped capacitors to elements at different positions in the array, this effectively compensates for the variations in equivalent inductance caused by these coupling differences, thereby stabilizing the array resonant frequency at the target frequency of 85 kHz. Finite element simulations demonstrate that the composite metamaterial array achieves a relative permeability near −1 at the target frequency and significantly optimizes the system's magnetic field distribution. Experimental results demonstrate that, over a transmission distance of 5 to 25 cm, the introduction of this composite metamaterial improves the system's transmission efficiency from 19.8%–49.3% to 40.1%–73.9%. Moreover, even under lateral displacement of the receiving coil, the system retains high efficiency, highlighting its improved robustness against misalignment.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156183"},"PeriodicalIF":3.2,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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