Pub Date : 2026-01-15DOI: 10.1016/j.aeue.2026.156218
Wan-Hao Xu , Junbing Duan , Lei Zhu , Cheng Liao , You-Feng Cheng , Ting Shi
This article investigates and analyzes the high-gain condition based on a vertically polarized (VP) endfire leaky-wave antenna by periodically loading parallel inductive elements on both sides of the double-sided parallel strip line. A radiation model of the employed leaky-wave antenna is firstly established to explore the effects of period length as well as propagation constants on the radiation gains and efficiencies. To achieve the high gain and efficiency, the structural influences of the antenna are then analyzed to explore the proper loading stub model to meet those requirements for the propagation characteristics. A prototype antenna is in final designed and fabricated to verify its performance in achieving high gain and efficiency radiation. The simulation results are in good agreement with the measured results, demonstrating the effectiveness of the resulted high-gain radiation condition for the VP endfire leaky-wave antenna.
{"title":"Proposal and analysis of high-gain vertically-polarized endfire leaky-wave antenna","authors":"Wan-Hao Xu , Junbing Duan , Lei Zhu , Cheng Liao , You-Feng Cheng , Ting Shi","doi":"10.1016/j.aeue.2026.156218","DOIUrl":"10.1016/j.aeue.2026.156218","url":null,"abstract":"<div><div>This article investigates and analyzes the high-gain condition based on a vertically polarized (VP) endfire leaky-wave antenna by periodically loading parallel inductive elements on both sides of the double-sided parallel strip line. A radiation model of the employed leaky-wave antenna is firstly established to explore the effects of period length as well as propagation constants on the radiation gains and efficiencies. To achieve the high gain and efficiency, the structural influences of the antenna are then analyzed to explore the proper loading stub model to meet those requirements for the propagation characteristics. A prototype antenna is in final designed and fabricated to verify its performance in achieving high gain and efficiency radiation. The simulation results are in good agreement with the measured results, demonstrating the effectiveness of the resulted high-gain radiation condition for the VP endfire leaky-wave antenna.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"207 ","pages":"Article 156218"},"PeriodicalIF":3.2,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145982035","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}
Vivaldi antennas used in Ground Penetrating Radar (GPR) systems often experience performance degradation at low frequencies due to inefficient radiation and impedance mismatch between the feedline and the tapered slot structure. To address these limitations, this paper presents a compact Vivaldi antenna employing a coplanar waveguide (CPW) feedline integrated with a single-stub matching technique. The stub position is analytically optimized to improve impedance matching over a broad frequency range. The CPW configuration simplifies the antenna structure by placing both the feedline and ground plane on the same substrate layer, resulting in a compact layout and facilitating broadband operation. The proposed antenna is fabricated on an FR-4 substrate with a thickness of and a relative permittivity of , with overall dimensions of . The measured results demonstrate broadband operation from 1.13 to 5 GHz. The antenna achieves a peak gain of 10.89 dBi in simulation and 10.36 dBi in measurement at 1.9 GHz, with a measured radiation efficiency of approximately 90.16% at the resonant frequency. The corresponding simulated and measured values of dB and dB indicate effective impedance matching at resonance, with minor discrepancies attributed to fabrication tolerances and measurement conditions. To assess practical feasibility, a preliminary sandbox-based GPR experiment was conducted using a pair of identical antennas in a bistatic configuration. The resulting A-scan response shows a distinct reflection corresponding to a buried metallic target at an estimated depth of 37.7 cm, which agrees well with the actual burial depth. These results indicate that the proposed antenna can support broadband GPR sensing within the investigated frequency range, while further system-level and field validations are recommended.
{"title":"CPW feed and stub optimization for Vivaldi antennas in broadband ground-penetrating radar applications","authors":"Kurnia Paranita Kartika Riyanti , Eko Setijadi , Gamantyo Hendrantoro , Nurhayati","doi":"10.1016/j.aeue.2026.156219","DOIUrl":"10.1016/j.aeue.2026.156219","url":null,"abstract":"<div><div>Vivaldi antennas used in Ground Penetrating Radar (GPR) systems often experience performance degradation at low frequencies due to inefficient radiation and impedance mismatch between the feedline and the tapered slot structure. To address these limitations, this paper presents a compact Vivaldi antenna employing a coplanar waveguide (CPW) feedline integrated with a single-stub matching technique. The stub position is analytically optimized to improve impedance matching over a broad frequency range. The CPW configuration simplifies the antenna structure by placing both the feedline and ground plane on the same substrate layer, resulting in a compact layout and facilitating broadband operation. The proposed antenna is fabricated on an FR-4 substrate with a thickness of <span><math><mrow><mn>1</mn><mo>.</mo><mn>6</mn><mspace></mspace><mi>mm</mi></mrow></math></span> and a relative permittivity of <span><math><mrow><msub><mrow><mi>ϵ</mi></mrow><mrow><mi>r</mi></mrow></msub><mo>=</mo><mn>4</mn><mo>.</mo><mn>3</mn></mrow></math></span>, with overall dimensions of <span><math><mrow><mn>80</mn><mo>×</mo><mn>80</mn><mo>×</mo><mn>1</mn><mo>.</mo><mn>635</mn></mrow></math></span> <span><math><msup><mrow><mi>mm</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span>. The measured results demonstrate broadband operation from 1.13 to 5 GHz. The antenna achieves a peak gain of 10.89 dBi in simulation and 10.36 dBi in measurement at 1.9 GHz, with a measured radiation efficiency of approximately 90.16% at the resonant frequency. The corresponding simulated and measured <span><math><msub><mrow><mi>S</mi></mrow><mrow><mn>11</mn></mrow></msub></math></span> values of <span><math><mrow><mo>−</mo><mn>61</mn><mo>.</mo><mn>21</mn></mrow></math></span> dB and <span><math><mrow><mo>−</mo><mn>39</mn><mo>.</mo><mn>13</mn></mrow></math></span> dB indicate effective impedance matching at resonance, with minor discrepancies attributed to fabrication tolerances and measurement conditions. To assess practical feasibility, a preliminary sandbox-based GPR experiment was conducted using a pair of identical antennas in a bistatic configuration. The resulting A-scan response shows a distinct reflection corresponding to a buried metallic target at an estimated depth of 37.7 cm, which agrees well with the actual burial depth. These results indicate that the proposed antenna can support broadband GPR sensing within the investigated frequency range, while further system-level and field validations are recommended.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"207 ","pages":"Article 156219"},"PeriodicalIF":3.2,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080292","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 : 2026-01-13DOI: 10.1016/j.aeue.2026.156215
Dongqi Chen , Kun Ye , Chuanxi Xing , Lang Zhou , Haixin Sun
This paper proposes a novel nested array (IAMDNA) by defining the positions of array elements through a special subarray design. This array can maintain the degrees of freedom (DOF) at a better level while greatly reducing the mutual coupling effect of the array. The paper presents closed-form expressions for the sensor positions and their corresponding DOFs in the novel nested array structure. Furthermore, through rigorous proof, the optimal array position expression for a specific number of sensors is derived. Array structure analysis and numerical simulation results show that, without considering array mutual coupling effects, the array’s estimation performance depends only on the DOFs. Based on this, the estimation accuracy of IAMDNA is slightly inferior to that of the comparison array. However, once the mutual coupling effect that must be considered in practical applications is introduced, the estimation accuracy of the IAMDNA array is significantly better than that of the comparison array, achieving a performance reversal. In conclusion, the physical structure of the IAMDNA array is sparser, which enables it to maintain excellent DOF while having greater practical application capabilities to resist mutual coupling effects.
{"title":"An improved sparse array design for improving DOA estimation performance under mutual coupling effect","authors":"Dongqi Chen , Kun Ye , Chuanxi Xing , Lang Zhou , Haixin Sun","doi":"10.1016/j.aeue.2026.156215","DOIUrl":"10.1016/j.aeue.2026.156215","url":null,"abstract":"<div><div>This paper proposes a novel nested array (IAMDNA) by defining the positions of array elements through a special subarray design. This array can maintain the degrees of freedom (DOF) at a better level while greatly reducing the mutual coupling effect of the array. The paper presents closed-form expressions for the sensor positions and their corresponding DOFs in the novel nested array structure. Furthermore, through rigorous proof, the optimal array position expression for a specific number of sensors is derived. Array structure analysis and numerical simulation results show that, without considering array mutual coupling effects, the array’s estimation performance depends only on the DOFs. Based on this, the estimation accuracy of IAMDNA is slightly inferior to that of the comparison array. However, once the mutual coupling effect that must be considered in practical applications is introduced, the estimation accuracy of the IAMDNA array is significantly better than that of the comparison array, achieving a performance reversal. In conclusion, the physical structure of the IAMDNA array is sparser, which enables it to maintain excellent DOF while having greater practical application capabilities to resist mutual coupling effects.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156215"},"PeriodicalIF":3.2,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977979","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 : 2026-01-12DOI: 10.1016/j.aeue.2026.156213
Shuaishuai Pan, Zhiyong Luo
Direction of Arrival (DOA) estimation has been applied in satellite applications. However, the growing demand for data volume has driven the gradual expansion of signal bandwidth, making broadband DOA estimation a critical challenge. Existing subspace-based DOA estimation algorithms usually exhibit weak performance and require prior information about the number of signals, limiting their practical applications. To address this issue, this paper proposes a novel broadband DOA estimation method based on covariance matrix reconstruction. First, focusing processing is applied to sampled data at different frequency points, and Eigenvalue Decomposition (EVD) is performed after obtaining the sample covariance matrix (SCM). Subsequently, a new clustering technique is developed by combining Gaussian Mixture Model (GMM) and Markov Random Field (MRF) theory to classify eigenvalues into signal and noise classes, thereby determining the number of signals. Then, a metric based on Kullback–Leibler (KL) divergence is constructed to measure subspace similarity and reconstruct the covariance matrix. Finally, DOA estimation is conducted using the reconstructed covariance matrix. Simulation results show that the proposed algorithms outperform other methods.
{"title":"Broadband DOA estimation with KL divergence for covariance matrix reconstruction","authors":"Shuaishuai Pan, Zhiyong Luo","doi":"10.1016/j.aeue.2026.156213","DOIUrl":"10.1016/j.aeue.2026.156213","url":null,"abstract":"<div><div>Direction of Arrival (DOA) estimation has been applied in satellite applications. However, the growing demand for data volume has driven the gradual expansion of signal bandwidth, making broadband DOA estimation a critical challenge. Existing subspace-based DOA estimation algorithms usually exhibit weak performance and require prior information about the number of signals, limiting their practical applications. To address this issue, this paper proposes a novel broadband DOA estimation method based on covariance matrix reconstruction. First, focusing processing is applied to sampled data at different frequency points, and Eigenvalue Decomposition (EVD) is performed after obtaining the sample covariance matrix (SCM). Subsequently, a new clustering technique is developed by combining Gaussian Mixture Model (GMM) and Markov Random Field (MRF) theory to classify eigenvalues into signal and noise classes, thereby determining the number of signals. Then, a metric based on Kullback–Leibler (KL) divergence is constructed to measure subspace similarity and reconstruct the covariance matrix. Finally, DOA estimation is conducted using the reconstructed covariance matrix. Simulation results show that the proposed algorithms outperform other methods.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156213"},"PeriodicalIF":3.2,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977981","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 : 2026-01-10DOI: 10.1016/j.aeue.2026.156209
Xinyu Zhang , Lijuan Zhong , Shidang Li , Yanping Zhou , Jianbin Cao , Chunguo Li
In practical wireless systems, transceiver hardware impairments (HWIs) introduce additional noise and nonlinear distortions, leading to degradation in physical layer security performance. In integrated sensing and communication (ISAC) systems, the transmitted waveform carrying communication information is susceptible to eavesdropping by sensing targets. To address this challenge, this paper investigates a reconfigurable intelligent surface (RIS)-assisted ISAC system that accounts for hardware impairments at both the transmitter and receiver. To enhance physical layer security and reduce information leakage to unauthorized users, we propose the strategic injection of artificial noise (AN) under certain conditions to degrade the signal quality at potential eavesdroppers. Specifically, we formulate a joint optimization problem involving sensing beamforming, artificial noise design, and RIS reflection coefficients, aiming to maximize the achievable secrecy rate while satisfying constraints on total transmit power, minimum communication rate, minimum radar sensing signal-to-noise ratio (SINR), and unit-modulus reflection coefficients. To solve the resulting non-convex problem, we first perform an equivalent transformation and decouple it into two non-convex subproblems. We then apply successive convex approximation (SCA) and semidefinite relaxation (SDR) to approximate the subproblems as convex programs. Finally, an alternating optimization (AO) algorithm is developed to efficiently solve the reformulated problem. Simulation results demonstrate that the proposed scheme effectively mitigates the performance degradation caused by hardware impairments and achieves an optimal trade-off between interference shaping and privacy preservation, outperforming conventional schemes without AN, RIS, or hardware impairment considerations.
{"title":"Joint robust beamforming design for RIS-assisted ISAC systems with hardware impairments","authors":"Xinyu Zhang , Lijuan Zhong , Shidang Li , Yanping Zhou , Jianbin Cao , Chunguo Li","doi":"10.1016/j.aeue.2026.156209","DOIUrl":"10.1016/j.aeue.2026.156209","url":null,"abstract":"<div><div>In practical wireless systems, transceiver hardware impairments (HWIs) introduce additional noise and nonlinear distortions, leading to degradation in physical layer security performance. In integrated sensing and communication (ISAC) systems, the transmitted waveform carrying communication information is susceptible to eavesdropping by sensing targets. To address this challenge, this paper investigates a reconfigurable intelligent surface (RIS)-assisted ISAC system that accounts for hardware impairments at both the transmitter and receiver. To enhance physical layer security and reduce information leakage to unauthorized users, we propose the strategic injection of artificial noise (AN) under certain conditions to degrade the signal quality at potential eavesdroppers. Specifically, we formulate a joint optimization problem involving sensing beamforming, artificial noise design, and RIS reflection coefficients, aiming to maximize the achievable secrecy rate while satisfying constraints on total transmit power, minimum communication rate, minimum radar sensing signal-to-noise ratio (SINR), and unit-modulus reflection coefficients. To solve the resulting non-convex problem, we first perform an equivalent transformation and decouple it into two non-convex subproblems. We then apply successive convex approximation (SCA) and semidefinite relaxation (SDR) to approximate the subproblems as convex programs. Finally, an alternating optimization (AO) algorithm is developed to efficiently solve the reformulated problem. Simulation results demonstrate that the proposed scheme effectively mitigates the performance degradation caused by hardware impairments and achieves an optimal trade-off between interference shaping and privacy preservation, outperforming conventional schemes without AN, RIS, or hardware impairment considerations.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156209"},"PeriodicalIF":3.2,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927444","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}
This paper proposes a broadband and compact filtering power divider (FPD) based on quarter circular/cambered (QCC) substrate integrated waveguide (SIW) and coplanar waveguide (CPW) resonators. Firstly, the impact of the CPW slot length on the quality factor (Q) of the QCC SIW resonator is analyzed. Subsequently, the CPW resonator is integrated into the QCC SIW to form a third-order bandpass filter (BPF) with a cascaded trisection (CT) topology. A transmission zero is located in the upper stopband. Finally, two third-order hybrid QCC SIW and CPW filtering power dividers (FPDs) with and without isolation resistors are designed. Furthermore, this paper introduces a new method for rapidly determining the quantity and value of isolation resistors. All the designs presented in this paper are simulated, manufactured, and experimentally validated. The measured results indicate that the proposed third-order FPD with isolation resistors operates at a center frequency of 5.08 GHz with a 3-dB FBW of 41.3% (2.1 GHz). The insertion loss (IL) is approximately (3 + 1.1) dB. The isolation between two output ports is better than 16 dB. A transmission zero (TZ) can be observed at 6.75 GHz in the right side of the passband attributing to the cross-coupling scheme, which enhances the out-of-band selectivity. The overall size of the proposed FPD with isolation resistors is 1.71λg × 1.49λg, and it features advantages of broad operating bandwidth, compact physical size, and low insertion loss.
{"title":"Broadband and compact filtering power divider employing quarter circular/cambered SIW and CPW structures","authors":"Ke-Long Sheng, Xiang Wang, Song-Song Qian, Zhi-Yuan Zong, Huangyan Li, Boyu Sima, Wen Wu","doi":"10.1016/j.aeue.2026.156196","DOIUrl":"10.1016/j.aeue.2026.156196","url":null,"abstract":"<div><div>This paper proposes a broadband and compact filtering power divider (FPD) based on quarter circular/cambered (QCC) substrate integrated waveguide (SIW) and coplanar waveguide (CPW) resonators. Firstly, the impact of the CPW slot length on the quality factor (<em>Q</em>) of the QCC SIW resonator is analyzed. Subsequently, the CPW resonator is integrated into the QCC SIW to form a third-order bandpass filter (BPF) with a cascaded trisection (CT) topology. A transmission zero is located in the upper stopband. Finally, two third-order hybrid QCC SIW and CPW filtering power dividers (FPDs) with and without isolation resistors are designed. Furthermore, this paper introduces a new method for rapidly determining the quantity and value of isolation resistors. All the designs presented in this paper are simulated, manufactured, and experimentally validated. The measured results indicate that the proposed third-order FPD with isolation resistors operates at a center frequency of 5.08 GHz with a 3-dB FBW of 41.3% (2.1 GHz). The insertion loss (IL) is approximately (3 + 1.1) dB. The isolation between two output ports is better than 16 dB. A transmission zero (TZ) can be observed at 6.75 GHz in the right side of the passband attributing to the cross-coupling scheme, which enhances the out-of-band selectivity. The overall size of the proposed FPD with isolation resistors is 1.71<em>λ</em><sub><em>g</em></sub> × 1.49<em>λ</em><sub><em>g</em></sub>, and it features advantages of broad operating bandwidth, compact physical size, and low insertion loss.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"207 ","pages":"Article 156196"},"PeriodicalIF":3.2,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025077","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}
This work presents a fractal 2-port multiple-input multiple-output (MIMO) antenna with wideband characteristics. The design covers a frequency range of 5.2–7.8 GHz, which falls under the C-band of the electromagnetic spectrum and achieves a 40% relative bandwidth at 6.5 GHz center frequency. The antenna has a compact dimension of 28 mm × 22 mm × 1.6 mm. It consists of two planar monopole radiating elements with partial ground modifications and a sequence of parasitic slots strategically placed in the ground plane. The identical radiating patches are positioned symmetrically to reduce correlation. Inductive resonant lines are incorporated into the ground plane to work as decoupling components. This suppresses surface current coupling between the antenna ports, thereby improving isolation despite using a low-cost substrate. A honeycomb defected ground structure (DGS) layout is etched, which helps in expanding the impedance bandwidth. It provides an isolation level of more than −15 dB. The diversity parameters like channel capacity loss (CCL), mean effective gain (MEG), etc. are found to be within the optimal limits. These traits make the small wideband antenna suitable for high-performance wireless applications such as the 5.9 GHz WLAN, 5.8 GHz Wi-Fi, and Wi-Fi 6/6E (IEEE 802.11ax), among others.
{"title":"Compact MIMO antenna employing inductive-capacitive coupling and honeycomb defected ground structure","authors":"Trishna Doloi , Gouree Shankar Das , Partha Protim Kalita , Yatish Beria , Reeta Devi , Akash Buragohain","doi":"10.1016/j.aeue.2026.156208","DOIUrl":"10.1016/j.aeue.2026.156208","url":null,"abstract":"<div><div>This work presents a fractal 2-port multiple-input multiple-output (MIMO) antenna with wideband characteristics. The design covers a frequency range of 5.2–7.8 GHz, which falls under the C-band of the electromagnetic spectrum and achieves a 40% relative bandwidth at 6.5 GHz center frequency. The antenna has a compact dimension of 28 mm × 22 mm × 1.6 mm. It consists of two planar monopole radiating elements with partial ground modifications and a sequence of parasitic slots strategically placed in the ground plane. The identical radiating patches are positioned symmetrically to reduce correlation. Inductive resonant lines are incorporated into the ground plane to work as decoupling components. This suppresses surface current coupling between the antenna ports, thereby improving isolation despite using a low-cost substrate. A honeycomb defected ground structure (DGS) layout is etched, which helps in expanding the impedance bandwidth. It provides an isolation level of more than −15 dB. The diversity parameters like channel capacity loss (CCL), mean effective gain (MEG), etc. are found to be within the optimal limits. These traits make the small wideband antenna suitable for high-performance wireless applications such as the 5.9 GHz WLAN, 5.8 GHz Wi-Fi, and Wi-Fi 6/6E (IEEE 802.11ax), among others.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156208"},"PeriodicalIF":3.2,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927449","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.2026.156206
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.
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