毫米波新月形柱面透镜天线设计

设计了一个毫米波均匀介质新月形柱面透镜天线。考虑到透镜天线设计中遇到的计算过程复杂、工作量大的问题,提出采用射线追踪法分析毫米波透镜天线,通过MATLAB编程仿真得到满意的效果。该结果与其他仿真结果基本吻合,但是具有省时和节省计算机存储空间等优点,可作为毫米波透镜天线设计的优选方案。     

Generation of Submillimeter-Wave Radiation with GaAs Tunnett Diodes and InP Gunn Devices in a Second or Higher Harmonic Mode

Efficient second-harmonic power extraction was demonstrated recently with GaAs tunnel injection transit-time (TUNNETT) diodes up to 235 GHz and with InP Gunn devices up to 325 GHz. This paper discusses the latest theoretical and experimental results from second-harmonic power extraction at submillimeter-wave frequencies and explores the potential of using power extraction at higher harmonic frequencies to generate continuous-wave radiation with significant power levels at frequencies above 325 GHz. Initial experimental results include output power levels of more than 50 W at 356 GHz from a GaAs TUNNETT diode in a third-harmonic mode and at least 0.2–5 W in the frequency range 400–560 GHz from InP Gunn devices in a third or higher harmonic mode. The spectral output of these submillimeter-wave sources was analyzed with a simple Fourier-transform terahertz spectrometer and, up to 426 GHz, with a spectrum analyzer and appropriate harmonic mixers. Initial experimental results from a GaAs/AlAs superlattice electronic device at D-band (110–170 GHz) and J-band (170–325 GHz) frequencies are also included.     

Smart Phase Tuning in Microwave Photonic Integrated Circuits Toward Automated Frequency Multiplication by Design

The author investigates the monitoring methods for fine adjustment of the previously proposed on-chip architecture for frequency multiplication and translation of harmonics by design. Digital signal processing (DSP) algorithms are utilized to create an optimized microwave photonic integrated circuit functionality toward automated frequency multiplication. The implemented DSP algorithms are formed on discrete Fourier transform and optimization-based algorithms (Greedy and gradient-based algorithms), which are analytically derived and numerically compared based on the accuracy and speed of convergence criteria.     

应用于ROF系统的微波光子发生器研究进展

介绍了光学生成毫米波技术研究的背景及意义.综述了几种主流的毫米波光学产生技术,主要包括直接调制法、外部调制法、光外差法,以及在此基础上的改进方法:如改进的双边带调制产生光毫米波方案,新型双均匀光栅结构产生毫米波的方法等.并介绍了2种新型光学生成毫米波方法,包括采用光纤光栅滤波器获得具有一定间隔双波长成分的光脉冲光谱实现...     

机载毫米波测云雷达吊舱关键技术研究

机载毫米波测云雷达是国内首部应用于科学研究的以飞机为载体的测云气象雷达,而其外挂系统——吊舱及其内装设备在空中飞行时的环境适应性、稳定性、可靠性等将决定项目成败。文章中对机舱外挂系统的关键技术——发射机环控技术和吊舱总装技术分别进行了研究,对工程实施的具体方案进行了详细论证,并组织了相关试验测试和数据分析,同时已顺利完成两个架次的有效飞行,确保了机舱外挂系统正常工作时的环境适应性、稳定性和可靠性,并为今后同类产品提供了设计借鉴。     

某气密封毫米波收发组件的故障统计与分析

毫米波组件作为毫米波电子系统的重要组成部分,其可靠性和故障率在很大程度上决定了整个毫米波系统的工作状态。目前,关于毫米波组件在批量使用过程中的可靠性情况和故障数据还鲜有研究。收集了某批量生产的毫米波收发组件在交付和使用中所出现的故障,并对故障进行了统计和分析,最后根据统计结果给出了技术和管理方面的改进建议。     

毫米波频段下MOSFET漏极电流噪声的统一模型

纳米级金属氧化物半导体场效应晶体管(MOSFET)精确的高频噪声模型是毫米波集成电路低功耗设计的重要基础,而现有的高频漏极噪声模型不仅没有融合器件的衬底效应和栅电阻效应,也没有充分考虑器件的频率和偏置依赖性。针对上述问题,基于纳米MOSFET器件的物理特性,并结合漂移扩散方程和有效栅极过载,建立统一表征强反区到弱反区的频率和偏置依赖性的漏极噪声模型,使之便于移植到先进设计系统(ADS)仿真设计。通过所建模型的仿真结果与实验测试结果进行比较,验证所建模型的准确性。同时比较所建模型对130 nm和40 nm MOSFET两种不同工艺器件的实用性,验证其对表征40 nm MOSFET的毫米波噪声特性的优越性。     

Multi-channel 28-GHz millimeter-wave signal generation on a silicon photonic chip with automated polarization control

We propose and experimentally demonstrate an integrated silicon photonic scheme to generate multi-channel millimeter-wave (MMW) signals for 5G multi-user applications. The fabricated silicon photonic chip has a footprint of 1.1 × 2.1 mm² and integrates 7 independent channels each having on-chip polarization control and heterodyne mixing functions. 7 channels of 4-Gb/s QPSK baseband signals are delivered via a 2-km multi-core fiber (MCF) and coupled into the chip with a local oscillator (LO) light. The polarization state of each signal light is automatically adjusted and aligned with that of the LO light, and then 7 channels of 28-GHz MMW carrying 4-Gb/s QPSK signals are generated by optical heterodyne beating. Automated polarization-control function of each channel is also demonstrated with ~7-ms tuning time and ~27-dB extinction ratio.     

被动毫米波实时成像技术

在简述当前被动毫米波二维成像技术已取得的成果及存在的不足的基础上,介绍了被动三维成像技术的原理、优势及难点. 对理想均匀球面阵列的被动三维成像性能进行了仿真分析,并着重对由成像遮挡问题引起的成像效果恶化进行了仿真评估. 最后提出了一种适用于非合作式人体安检的“门”型通道成像阵列,并对其能够实现的被动三维成像效果进行了探讨. 结果表明,所提出的“门”型通道成像阵列理论能够实现波长级的被动三维成像分辨率.

     

一种基于幅度补偿的毫米波近场成像算法

毫米波近场全息成像中通常忽略幅度因子影响成像质量,且成像效率较低。针对以上问题,提出一种基于幅度补偿的近场成像算法。该算法首先对雷达回波信号进行幅度补偿,然后采用降维操作降低算法复杂度。实验结果表明,相对于全息成像,所提近场成像算法不仅可以提高图像重构质量,还能加快成像处理速度。