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

Conventional power amplifiers often struggle to achieve effective impedance matching over a wide band width, resulting in increased power loss and poor harmonic suppression. In response to the requirements of modern RF communication systems for broadband and high efficiency, this paper proposes a power amplifier design scheme based on a Chebyshev low-pass filter with high and low impedance characteristics and an L-type parasitic harmonic compensation network. The design successfully suppresses high harmonics and improves frequency selectivity and impedance matching by introducing this filter. In addition, an L-type parasitic harmonic compensation network is used to extend the bandwidth and further enhance the flexibility of the impedance matching. The designed power amplifier operates in the frequency band of 0.9-1.6 GHz, centered at 1.25 GHz. Experimental results show that the gain maintains stability (>16 dB) in the lower power range and decreases significantly when the output power exceeds 20 dBm, indicating a gain compression phenomenon. The power added efficiency increases significantly once the output power exceeds 10 dBm and peaks near 30 dBm (about 60%), demonstrating high efficiency characteristics. Comprehensive experimental and simulation results validate the high performance and effectiveness of the power amplifier in the target frequency band. © 2025 IEEE.

This article proposes a method for implementing a broadband power amplifier with step impedance transformation. Based on broadband matching technology, it has good power characteristics in the range of 470MHz-860MHz through step impedance transformation. Finally, using self-developed RF-LDMOS device, a power amplifier was fabricated and tested. The test results showed that the output power reached 47dBm and the drain efficiency reached 55%, verifying the feasibility and effectiveness of the proposed scheme, which has important application value in 5G communication base stations and radar systems. © 2025 IEEE.

In order to solve the problem of reduced efficiency due to harmonic interference in multi-band power amplifiers, a dual-frequency, dual-port, high-efficiency power amplifier with harmonic suppression has been designed. A cascade design of a π-type harmonic suppression network and a multi-branch single-frequency matching network has been proposed. This design suppresses the harmonics generated by each branch under the condition of realizing multi-frequency and multi-channel. It improves the amplifier's efficiency and does not have an impact on the subsequent fundamental matching. The efficiency of the amplifier is enhanced, and it does not impact the subsequent fundamental matching. In order to verify the experiment's feasibility, the designed power amplifier was simulated and tested. The electromagnetic simulation results indicate that the output power at 0.9 GHz and 2.4 GHz is 40.5 dBm and 40.3 dBm, respectively. The drain efficiency is 69% and 68.3%, the gain is 11.5 dB and 10.8 dB, and the difference in the second and third harmonics power fundamental power is -48 dBm and above. © 2025 IEEE.