Aeu-International Journal of Electronics and Communications最新文献

{"title":"Design of a flexible compact insensitive wearable antenna for enhanced performance stability","authors":"Yarram Uma Maheswari,&nbsp;Bappadittya Roy","doi":"10.1016/j.aeue.2025.156143","DOIUrl":"10.1016/j.aeue.2025.156143","url":null,"abstract":"<div><div>This work introduces a portable conformal antenna developed for advanced body-centric wireless systems operating in the 2.45 GHz ISM band (Industrial, Scientific, and Medical) with extended resonances near 10.5 and 12.5 GHz. The antenna integrates a <span><math><mi>π</mi></math></span>-shaped slot within a diamond-shaped patch antenna (DPA) and uses a Defected Ground Structure (DGS) to improve BW (Band Width) and radiation characteristics. Fabricated on a flexible felt substrate, the design achieves a low-profile volume of 0.294 <span><math><mo>×</mo></math></span> 0.294 <span><math><mo>×</mo></math></span> 0.0163 <span><math><msup><mrow><mi>λ</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span>. A wide impedance bandwidth of 3.8 GHz (2–5.8 GHz) with VSWR <span><math><mrow><mo>&lt;</mo><mn>2</mn></mrow></math></span> is achieved, supporting robust multi-band operation. Additional high-frequency resonances enable applications such as biomedical imaging and high-resolution sensing. This design achieves a gain of 5.2 dBi at 2.45 GHz and 8.4 dBi at 5.8 GHz, a radiation efficiency of 90%, and a simulated Specific Absorption Rate (SAR) of 0.0031 Watts per kilogram, according to IEEE safety standards. Due to its broadband performance, low SAR, and mechanical flexibility, the proposed antenna is a strong candidate for future triband wearable communication and sensing systems.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"205 ","pages":"Article 156143"},"PeriodicalIF":3.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571869","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}

{"title":"An improved sparse array design for improving DOA estimation performance under mutual coupling effect","authors":"Dongqi Chen ,&nbsp;Kun Ye ,&nbsp;Chuanxi Xing ,&nbsp;Lang Zhou ,&nbsp;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":"2026-02-01","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}

{"title":"Independent and asymmetric coupling structure for integrated dual-band bandpass filter with microwave microfluidic milk sensor","authors":"Teguh Firmansyah ,&nbsp;Supriyanto Praptodiyono ,&nbsp;Imamul Muttakin ,&nbsp;Irma Saraswati ,&nbsp;Adi Nugraha ,&nbsp;Syah Alam ,&nbsp;Habib Nurseha Anggradinata ,&nbsp;Ken Paramayudha ,&nbsp;Yuyu Wahyu ,&nbsp;Teguh Handoyo ,&nbsp;Aloysius Adya Pramudita ,&nbsp;Gunawan Wibisono ,&nbsp;Mudrik Alaydrus ,&nbsp;Muhammad Iqbal ,&nbsp;Nugraha","doi":"10.1016/j.aeue.2025.156186","DOIUrl":"10.1016/j.aeue.2025.156186","url":null,"abstract":"<div><div>This study proposes an independent and asymmetric coupling structure for an integrated dual-band bandpass filter (BPF) with microwave microfluidic sensor. The proposed device features a three-port configuration where the dual-band BPF structure employs a coupled stepped impedance resonator (SIR), while the MS utilizes an interdigital capacitor (IDC) bridge structure located at the center of the ring resonator. The proposed structure was fabricated on a Rogers RT/Duroid 5880 substrate with εr = 2.2 and tan δ = 0.0009. Liquid samples, including a milk-water mixture and a milk-glucose mixture, were used for testing, each with a volume of 21.2 μL. Results demonstrate that the device provides dual-band BPF functionality with center frequencies of 2.16 GHz and 2.54 GHz, insertion losses (|S₂₁|) of −1.30 dB and − 1.20 dB, and fractional bandwidths (FBWs) of 2.13 % and 3.34 %, respectively. For the MS application, the device achieved a frequency shift (Δf) of 32.0 MHz and a normalized sensitivity (NS) of 0.064 % for the milk-water mixture. Additionally, for the milk-glucose mixture, the MS exhibited sensitivities of 3.75 × 10⁻³ dB/(mg/dL) and 5.00 kHz/(mg/dL) based on the magnitude and peak location of the transmission coefficient, respectively. The device also exhibited an isolation value (|S₃₂|) of less than −25 dB, indicating minimal interference between the dual-band BPF and the MS. This high isolation enables both components to operate independently. Finally, the proposed device structure holds potential for future applications such as supporting food safety while also offering radio frequency filtering functionalities.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156186"},"PeriodicalIF":3.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842266","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}

{"title":"A differentially fed dual-band dual-polarized filtering antenna with high selectivity","authors":"Yi Cao ,&nbsp;Zhipeng Xia ,&nbsp;Jianpeng Wang ,&nbsp;Lei Ge","doi":"10.1016/j.aeue.2025.156169","DOIUrl":"10.1016/j.aeue.2025.156169","url":null,"abstract":"<div><div>In this paper, a differentially fed dual-band dual-polarized filtering antenna with high selectivity is proposed for application in n78 and n79 band of fifth-generation (5G) communication. Based on two stacking circular patches working in TM₁₁ mode, two radiating frequency with dual polarization is initially indicated respectively at 3.5 GHz and 4.8 GHz. Subsequently, slots, T-branches, parasitic patches, and shorting posts are introduced to expand the bandwidth of lower-band and upper-band. Meanwhile the combination of slots, parasitic patches and shorting posts successfully introduced four radiation zeros which highly improved the selectivity. Measured results show that the proposed antenna exhibits a low profile of 0.04<em>λ</em>₀ and provides impedance bandwidths of 4 % (3.45–3.59GHz) and 6.7 % (4.59–4.91 GHz) along with maximum gains of 5.8 dBi and 8.6 dBi respectively at two working band. As expected, four radiation zeros are observed on realized gain which indicates a good selectivity.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156169"},"PeriodicalIF":3.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799835","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}

{"title":"Neural network-assisted quad-port UWB MIMO antenna with enhanced isolation for WLAN and Sub-6 GHz wireless applications","authors":"Killol Pandya ,&nbsp;Tigmanshu Patel ,&nbsp;Aneri Pandya ,&nbsp;Trushit Upadhyaya ,&nbsp;Upesh Patel ,&nbsp;Om Prakash Kumar","doi":"10.1016/j.aeue.2025.156184","DOIUrl":"10.1016/j.aeue.2025.156184","url":null,"abstract":"<div><div>The presented paper focuses on Neural Network (NN) based quad-port Multiple Input Multiple Output (MIMO) antenna development and analysis for 2.4/5 GHz WLAN, sub-6 GHz, and C-band communications. The engineered design exhibits the reflection coefficient values below-10 dB from 2.20 GHz to 11.70 GHz frequencies. The limited ground is proposed to attain the UWB response. The radiators are located orthogonally to each other at a minimum distance of half of the wavelength to minimize the mutual coupling effect. The flame-retardant material has been utilized to act as a substrate material with a dielectric constant is 4.3. The isolation geometry was developed and integrated with the ground structure to further improve the isolation. The conventional response has been generated using HFSS software. The proposed structure exhibits a gain of about 2 dBi, and efficiency is about 85 % to 90 %. The neural network has been trained, and the sets of data are given as input parameters to the NN. The NN predicted response was in line with the software-generated response. The values of diversity parameters, such as Channel Capacity Loss (CCL) is 0.001 bits/s/Hz, Envelop Correlation Coefficient(ECC) is 0.001 abs, Mean Effective Gain (MEG) is between −4 dB to −6 dB, and Diversity Gain (DG) is around 10 dB, were received. This work supports SDG 9 (Industry, Innovation and Infrastructure) by advancing AI-assisted wireless communication design and SDG 11 (Sustainable Cities and Communities) through improved reliability of WLAN and Sub-6 GHz systems.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156184"},"PeriodicalIF":3.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885915","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}

{"title":"Increasing transfer gap while maximizing load power by selecting topologies in wireless power transfer system","authors":"Lunde Ardhenta ,&nbsp;Ichijo Hodaka ,&nbsp;Takuya Hirata","doi":"10.1016/j.aeue.2025.156185","DOIUrl":"10.1016/j.aeue.2025.156185","url":null,"abstract":"<div><div>The coupling coefficient as well as the operating frequency increases or decreases the load power in a wireless power transfer system. The parameter space of coupling coefficient and operating frequency is divided into over-, critically-, and under-coupled regions. The load power at over- and under- coupled regions drops from the critically-coupled region where the power is ideally maximized. This situation for series–series topology has been clarified in the conventional studies. In this paper, the critically-coupled region or critical coupling coefficient for series-parallel and parallel-series topologies is revealed in a mathematically form. The results of this paper suggest a selection of topology to improve load power over longer distance in wireless power transfer.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"206 ","pages":"Article 156185"},"PeriodicalIF":3.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885917","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}

{"title":"Design and application of differentiated compensation metamaterials for wireless power transfer system","authors":"Xingming Fan,&nbsp;Yihao Chen,&nbsp;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":"2026-02-01","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}

{"title":"Improving an Indoor RIS Surface Location via the Motley-Keenan Model and a Two-Stage Grid Search Algorithm","authors":"Basma Nazar,&nbsp;Sarab Kamal Mahmood,&nbsp;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":"2026-02-01","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}

{"title":"DFnT based Orthogonal Time Chirp Space modulation over time-varying channels","authors":"Heng Xiong,&nbsp;Jiaojiao Liu,&nbsp;Nan Sun,&nbsp;Biyun Ma","doi":"10.1016/j.aeue.2025.156170","DOIUrl":"10.1016/j.aeue.2025.156170","url":null,"abstract":"<div><div>This paper proposes an Orthogonal Time Chirp Space (OTCS) system based on discrete Fresnel transform (DFnT). The novelty lies in modulating data symbols in the delay-Fresnel Doppler plane onto the two-dimensional (2D) complex chirped carriers, thereby utilizing the interference resistance of the chirp waves to improve system performance. Since a combination of inverse DFnT and discrete Fourier transform is adopted, the DFnT-OTCS system incurs minimal additional complexity compared to Orthogonal Time Frequency Space (OTFS). In addition, their equivalent channel matrices are proved the same sparsity. Simulation results over time-varying channels demonstrate under high signal-to-noise ratio (SNR) conditions, DFnT-OTCS outperforms OTFS and discrete fractional Fourier transform (DFrFT)-OTCS in terms of bit error rate (BER), especially in high speed applications.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"205 ","pages":"Article 156170"},"PeriodicalIF":3.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790137","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}

{"title":"A periodically loaded line phase shifter based on spoof plasmon polariton concept","authors":"Jie Ma ,&nbsp;Zhi Yu Bi ,&nbsp;Zhan Yi Fu ,&nbsp;Han Zhang ,&nbsp;Li Wei Yan ,&nbsp;Xiao Jian Fu ,&nbsp;Jun Wei Wu ,&nbsp;Fei Yang","doi":"10.1016/j.aeue.2025.156177","DOIUrl":"10.1016/j.aeue.2025.156177","url":null,"abstract":"<div><div>This paper presents a loaded-line phase shifter with wide phase-shifting range based on Spoof Surface Plasmon Polaritons (SSPPs) with interdigital capacitors and p-i-n diodes. The operating principle of digital phase shifting is first investigated, followed by an analysis of the dispersion characteristics. Through tailored dispersion engineering, a phase shifter based on the proposed unit cells is then designed, with simulated transmission characteristics validating the dispersion analysis. Experimental measurements confirm the design’s clear superiority over conventional loaded-line phase shifters. The fabricated prototype exhibits a stable phase shift step from 4.5 GHz to 5.2 GHz, a phase shift range of 0°to 280°, and an insertion loss below 3 dB.</div></div>","PeriodicalId":50844,"journal":{"name":"Aeu-International Journal of Electronics and Communications","volume":"205 ","pages":"Article 156177"},"PeriodicalIF":3.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790138","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}