随着5G系统数据流量的快速增长，毫米波技术在5G等工业和学术应用领域引起了广泛的关注，但由于相关的高路径损耗衰减、多路径干扰等特点，引入多输入多输出(MIMO)技术来提高其无线通信的频谱效率和覆盖范围。设计了一种基于回型环去耦结构的紧凑型陷波毫米波MIMO天线，整体尺寸仅为24 mm×18 mm×0.8 mm。天线整体刻蚀在FR4—KB板材上，通过在天线辐射贴片刻蚀“H”型缝隙，实现了n258(24.25-27.5 GHz)频段的陷波。进一步，在接地板设置回型环结构来产生高频谐振点，使得MIMO天线获得良好的去耦效果。仿真与测试结果可以看出：该宽带毫米波天线工作频段为20.9-33.2 GHz(相对带宽达到49%),隔离度均大于18.2 dB,满足MIMO天线隔离度要求，包络相关系数(ECC)小于0.004,具有良好的辐射效率和增益性能，可以广泛用于毫米波MIMO天线通信系统。

This paper proposes a lightweight antenna surrogate model based on a one-dimensional grouped-and-pointwise heterogeneous convolutional neural network (1D GP-HetCNN) for the prediction of the scattering parameter () curve of antennas. Using antenna physical parameters as the input, the surrogate model can predict the curve efficiently and accurately. Then, in order to study complicated frequency features of curves, the 1D GP-HetCNN model is further combined with a multi-task learning method, constructing 1D GP-HetCNN-MTL. Based on the two trained surrogate models, two optimization methods employing the whale optimization algorithm and the coati optimization algorithm are developed respectively. On the test set, the 1D GP-HetCNN model achieves the root mean square error (RMSE) of 0.0305 and the mean absolute error (MAE) of 0.0189; the 1D GP-HetCNN-MTL model achieves the RMSE of 0.0426 and the MAE of 0.0282. Both surrogate models perform better than the two baseline models. Moreover, results from the two optimization methods show that they can identify improved physical parameters with a wider operating bandwidth from 19.3 GHz to averagely 20.0 GHz more efficiently than conventional electromagnetic (EM) simulation, which increases the fractional bandwidth from 155.02% to averagely higher than 156%. These findings indicate that surrogate models combined with intelligent optimization algorithms can accelerate antenna modeling and further improve the antenna’s EM performance. Overall, the proposed approach facilitates more efficient antenna design and contributes to the development of intelligent antenna engineering. © The Author(s) 2025.

针对近眼微型化三维全息成像显示存在的多片组结构、景深受限的问题，提出了融合“超表面透镜的高横向分辨率”与“轴棱锥的长焦深”特性的超表面轴锥透镜结构设计，采用全息图相位、轴棱锥镜相位与聚焦相位叠加的编码策略。通过系统验证不同焦距与超表面半径的组合性能，筛选适配近眼显示的核心参数，同时为避免全息图像因空间挤压导致相位调制交叉干扰，选取目标图像为300像素。采用FDTD对所设计超表面轴锥透镜性能进行仿真，结果表明单个超表面单元在保持85%以上偏振转换效率的同时，偏振串扰小于-15dB。采用610nm准直光源，当超表面轴锥透镜半径为15μm，焦距为60μm时，在60-90μm焦深范围内仍能形成清晰的高分辨全息图像。与传统超透镜相比，本设计所成全息像景深提升了40%。所提出大景深超表面轴锥透镜，在保持高分辨成像质量的同时，能够极大地降低光学系统对准焦平面的光场适配难度，为近场成像和微型全息显示提供了高水平的成像透镜理论及解决方案，在近眼显示领域中具有重要意义。

To address the growing demand for wideband and high-gain antenna solutions in modern high-frequency communication systems, a metasurface (MTS) antenna is proposed based on characteristic mode theory (CMT). The proposed antenna consists of an MTS structure, a dual-layer Rogers 5880 dielectric substrate, a ground plane, and an L-shaped microstrip feed line. The MTS consists of a 4 x 4 array of modified rectangular unit cells, with additional rectangular parasitic elements placed along its periphery. Through the synergistic interaction between the multislot structure and the parasitic elements, the surface current distribution is effectively tailored, modifying the modal current paths and enabling the excitation of a greater variety of wideband modes. This lays a solid foundation for the wideband operation of the antenna. Furthermore, an inductively coupled feeding structure is designed to optimize the impedance matching performance. Both simulation and measurement results confirm that the proposed antenna operates over a frequency range of 14.13 GHz to 38.98 GHz, achieving a relative bandwidth of 93.6% and a peak gain of 11.4 dBi. The radiation patterns remain stable across the operating band, with the radiated energy highly concentrated in the main lobe direction. The proposed design makes it a promising candidate for applications in 5G millimeter-wave communications, satellite multiband integrated systems, and ultra wideband radar sensing.

Broadband power amplifiers (PAs) not only demand high efficiency and linearity but also face stringent challenges regarding the flatness of their gain and efficiency; the nonideality of baseband impedance is a key factor that leads to nonlinear distortion and dynamic performance fluctuations, impacting the PA's performance flatness. In this paper, a passive multibranch baseband impedance control unit (BICU) is proposed to provide a low and flat controllable impedance over the wide baseband frequency range of 1-600 MHz, and a broadband PA incorporating this BICU is designed and tested. Experimental results demonstrate that introducing the BICU in the 1.8-2.4 GHz range effectively stabilizes the baseband impedance, significantly improving the flatness of the power-added efficiency (PAE), which remains relatively stable at around 62% with reduced fluctuations across the operating band. Simultaneously, at an output power of approximately 38 dBm, the third-order intermodulation distortion (IMD3) improved by about 3-5 dBc, exhibiting significantly suppressed sideband asymmetry, thus enhancing linearity, whereas the gain was maintained at around 12 dB. This research validates the feasibility of improving the linearity, efficiency flatness, and overall performance flatness of broadband PA by optimizing the baseband impedance.

提出了一种具有高隔离度的三陷波超宽带(UWB)—多输入多输出(MIMO)天线，整体尺寸为23 mm×31 mm×1.6 mm。通过对辐射贴片底部两侧进行倒“W”型切角和窄化馈线，实现了UWB;将接地板改进为阶梯“T”型去偶结构，并开半圆形凹槽，实现了较高隔离度；在馈线上刻蚀类“回”字型缝隙、在辐射贴片上刻蚀“U”型缝隙以及在右侧加载类“U”型寄生枝节，实现了WLAN(5.15-5.85 GHz)、X波段(7.25-7.75 GHz)和国际电信联盟(ITU)(8.01-8.5 GHz)3个频段的陷波。仿真与测试结果表明：该天线工作频段为3.09-12 GHz(相对带宽达到118%),隔离度小于-21.55 dB,包络相关系数(ECC)小于0.01,辐射效率高，辐射特性良好，设计的天线可以广泛应用于无线通信系统领域中。

In this paper, the Single-Event Burnout (SEB) triggering mechanism of 1200 V 4H-SiC Lateral Diffused Metal Oxide Semiconductor (LDMOS) is numerically studied based on Sentaurus TCAD electro-thermal coupled simulations. A hardened design of source-extended combined with a triple-buffer layer is proposed. Simulation results show that impact ionization plays an important role in the SEB triggering of SiC LDMOS. With the introduction of a triple-buffer layer that can effectively suppresses and integrates the peak electric field, thereby weakening impact ionization. Meanwhile, the source-extended can extract the holes rapidly and suppress the parasitic BJT positive feedback, thus avoiding the thermal damage caused by excessive current. Under the optimal parameters, the SEB threshold voltage (VSEB) of the proposed structure is 259% higher than the conventional structure. © 2025

This study investigates the relation between the physical parameters and scattering parameter (S11) curves of antennas, and proposes two deep-neural-network-based frameworks respectively for antenna forward and inverse designs, improving the design efficiency compared to the conventional electromagnetic (EM) simulation approaches. In this study, a one-dimensional (1D) U-Net is utilized as the backbone of the two models and is enhanced with multiple mechanisms — diffusion mechanism, channel attention, and spatial attention. Therefore, the models more effectively capture the sequential features of data. In the forward design, the model quickly predicts the S11 curves from given physical parameters with an accuracy improvement of at least 63% RMSE and 70% MAE compared to the improved one-dimensional convolutional neural network (1D-MCNN) and deep multi-layer perceptron (DMLP), thus realizing the surrogate model of conventional methods to some extent. In the inverse design, another model directly infers the physical parameters corresponding to the target S11 curves with an accuracy improvement of at least 21% RMSE and 38% MAE compared to the baseline models (1D U-Net and MLP), thereby eliminating the iterative process of traditional methods and accelerating the antenna design. The experimental results demonstrate the significant advantages of the proposed deep neural network frameworks in terms of accuracy and efficiency for both forward and inverse designs of antennas, offering a powerful alternative to conventional electromagnetic simulation-based approaches. © 2025, Electromagnetics Academy. All rights reserved.

To deal with the problems of low gain and low data transmission rate of millimeter wave antenna during long-distance trans-mission, a high-gain millimeter wave array multiple-input-multiple-output (MIMO) antenna with series-parallel hybrid feed is proposed. The radiating structure consists of a combination of multiple rectangular patches, to make the proposed design resonate within the desired frequency band of 39 GHz. The antenna line array consists of eight radiating patches connected in series via transmission lines, providing an operating bandwidth of 1.02 GHz and a peak gain of 15.9 dB, and utilizing the Chebyshev synthesis method to control the side lobe level below −20 dB. In order to obtain higher gain, two antenna line arrays are connected through a Y-shaped feeding network, which utilizes the mutual coupling between the antennas to increase the bandwidth of the antenna to 1.25 GHz and provide a simulated gain of 17.6 dBi. Furthermore, the proposed array antennas are placed side-by-side to form a four-port MIMO antenna, which does not require any decoupling structure and has the isolation of more than 25 dB. The radiation efficiency is as high as 99%, the Envelope Correlation Coefficient (ECC) less than 0.003, and the Diversity Gain (DG) greater than 9.98. The measured results show that the operating frequency band of the antenna is 38.0 ∼ 39.6 GHz, and the operating bandwidth is 1.6 GHz. In the operating frequency band, the peak gain of the antenna is 17.45 dBi. Finally, the frequency characteristics and radiation characteristics of the antenna when bending are analyzed. The results show that the bending of the antenna leads to a slight shift in the resonant frequency, but the relative bandwidth remains unchanged. The gain has decreased, indicating that the antenna is able to work normally after bending and has a wider range of application scenarios. © 2025, Electromagnetics Academy. All rights reserved.

Low-emissivity glass, commonly employed in building curtain walls, strongly reflects and weakly transmits millimeter-wave signals, thereby hindering signal propagation. To address this issue, this paper introduces a novel method that leverages the low-emissivity film itself to design a metasurface for enhanced signal transmission. Two specific metasurface designs are presented. The simulation results validate the proposed method. For the design targeting linearly polarized waves, a 23 dB enhancement in the transmitted electric field is achieved compared to that of uncoated glass. The design for circularly polarized waves achieves a 22 dB enhancement. Both metasurfaces exhibit excellent wide-angle performance, maintaining single-point focusing up to a 30◦ incidence angle with an electric field enhancement exceeding 15 dB. The proposed millimeter-wave transparent metasurface features a simple structure, supports wide-angle incidence, and can be deployed over large areas with adjustable focal points to meet communication requirements. This work provides a reliable solution for mitigating millimeter-wave transmission loss through low-emissivity glass. © 2025, Electromagnetics Academy. All rights reserved.