微带型回音壁模介质谐振器带阻方向滤波器

本文报道了使用新型平面回音壁模介质谐振器的微带型毫米波带阻、方向滤波器。全文用行波环谐振器的方法进行分析,并给出了Ka波段带阻、方向滤波器的实验研究,其结果表明,该谐振器特别适用于毫米波微带集成电路。     

双谱用于毫米波雷达目标特征提取的研究

在毫米波雷达系统中,信噪比对作用距离的影响很大。本文利用双谱技术提取出目标信号双谱的局部相位信息作为特征矢量;该特征良好的抗噪性大大降低了目标识别对雷达系统信噪比的要求,从而提高了毫米波雷达的灵敏度及作用距离。     

Ka波段HEMT噪声系数测试

介绍了Ka波段HEMT及其单片低噪声放大器的测试方法，着重分析了低频振荡原因和抑制方法，探讨了毫米波电路测试的特点，最后给出了测试结果。     

气密性高Bs合金及其在微波管中的应用

本文简要介绍了新型气密性高饱和磁感应（Ｂｓ）合金的主要特点及其在真空微波管中的应用。     

Foreign-body detection in dry food using continuous sub-terahertz wave imaging

Recently, significant attention has been paid to the food safety issue of foreign-body detection in the food industry. Commercialized X-ray imaging is extensively used for monitoring any foreign bodies that may be embedded in food products. However, foreign bodies such as low-density organic materials cannot be easily observed by conventional detection methods. The sub-terahertz and terahertz wave methods can provide not only the identification of a low-density foreign body but also a safe inspection due to the non-ionizing radiation. In this study, foreign bodies concealed in dry food were detected with a high-resolution raster scan imaging system at 210 GHz in the sub-terahertz wave range. Our raster-scan imaging system using Gaussian beam focusing demonstrated the diffraction-limited spatial resolution in the sub-terahertz wave range. Transmission images of foreign bodies showed better contrast than reflection images. Nondense materials, such as insects and plastics, were observed with the continuous sub-terahertz wave, in contrast to the difficulty in observing them in X-ray transmission imaging.     

Design of a W-band Stepped-frequency Synthesizer with Fast Frequency Switching

In this paper, a W-band coherent stepped-frequency synthesizer is proposed, which provides transmitter and local oscillator signals to a high range resolution radar system. This synthesizer is realized by combining the technique of direct digital synthesizer, phase lock loop, up-conversion and multiplier chain, etc. In order to shorten the lock time of the phase lock loop, a new method is introduced in the design of this synthesizer. Measurement results show that the transmitting signal is around 94 GHz, the bandwidth is 504 MHz, the phase noise is about −90 dBc/Hz at 10 kHz offset, and the spurious signals are less than −55 dBc. Especially, the frequency switching time of this synthesizer is about 1 μs. With the W-band stepped-frequency synthesizer, the range resolution of the high range resolution radar system is better than 0.6 m.     

Ka波段多注速调管的研制

主要介绍了一支Ka波段多注速调管的研制进展;该设计方案在毫米波段采用了多注技术和分布作用腔技术,给出了采用CAD技术对各部分分析计算的结果,包括总体设计、电子光学设计、高频互作用段设计,最后与实验结果进行了对比验证,给出了改进方向。     

采用二极管的射频预失真毫米波功放线性化器

文章提出了一种Ka波段的射频预失真线性化器.它由一个GaAs肖特基二极管和一个电容并联构成,通过一个偏置电阻加入直流馈电,具有增益扩展和相位延迟的特性,并且其增益和相位特性具有可调性,尤其其相位特性可调性更强.将其应用于工作频率为30GHz饱和输出功率为10W的功放,输出三阶交调失真(IMD3)可以改善15dBc以上,此时功放输入的双音激励信号频率间隔为5MHz.该线性化器可调性强、结构简单、成本低廉、易于实现,有着非常大的工程应用价值.     

微波数字频率计的毫米波扩展

本文论述了采用外部单端谐波混频器技术扩展微波数字频率计频率测量范围的一种方法 ,并就国产微波数字频率计研制了一套微波混合集成 (HMIC)扩展功能模块 ,着重分析了提高测试灵敏度的主要因素和参数选择方法。在Ka 波段对模块的主要指标进行了测试 ,取得了较好结果     

Millimeter-Wave Ultra-Wideband Bandpass Filter Employing Dual-Mode Ring Resonators Fed by Step-Impedance Coupled Lines

This paper presents a novel millimeter-wave ultra-wideband (UWB) bandpass filter (BPF) based on microstrip dual-mode rectangular ring resonators. In order to get strong coupling between the input/output line and the dual-mode ring resonators, a step-impedance parallel-coupled structure is adopted for the design of the filter. On the other hand, transmission zeros are produced by the dual-mode resonator. As a consequence, the filter has low insertion-loss in its passband, sharp attenuation in its lower and upper stopbands and very wide stopbands. As an example, a filter with two dual-mode ring resonators is designed and fabricated. The measured frequency property of the fabricated filter shows good agreement with the simulated response.