共查询到20条相似文献,搜索用时 93 毫秒
1.
S波段连续波SiC功率MESFET 总被引:1,自引:1,他引:0
利用国产SiC外延材料和自主开发的SiC器件工艺加工技术,实现了SiC微波功率器件在S波段连续波功率输出大于10W、功率增益大于9dB、功率附加效率不低于35%的性能样管,初步显现了SiC器件在S波段连续波大功率、高增益方面的优势。与以往的硅微波功率器件相比,在同样的频率和输出功率下,SiC微波功率器件的体积不到Si器件的1/7,重量不到Si器件的20%,其功率增益较Si器件提高了3dB以上,器件效率也得到了相应的提高。同时由于SiC微波功率器件的输入、输出阻抗要明显高于Si微波功率器件,在一定程度上可以简化或不用内匹配网络来得到比较高的微波功率增益,这就为器件的小体积、低重量奠定了基础,也为器件的大功率输出创造了条件。 相似文献
2.
为了提升电容式MEMS微波功率传感器的测量灵敏度,本文充分利用传感器的内部空间结构,提出了一种基于对称双悬臂梁结构的电容式微波功率传感器。根据对称式双梁结构的特点,建立了对称双悬臂梁结构的枢纽式机电模型。研究和分析了对称双悬臂梁结构的测量灵敏度和过载功率。实验结果表明,在悬臂梁初始间距相同的条件下,对称双梁结构的测量灵敏度相较传统单梁结构提高了3倍;同时,通过改变悬臂梁的初始间距,可以实现较大范围内传感器测量灵敏度与过载功率两项指标的折中与转化,以满足更加广泛的设计需求。 相似文献
3.
4.
介绍了一种对称矩形环栅NMOS器件结构,并对其等效宽长比的计算模型和总剂量效应加固性能进行了研究。通过区域划分、保角变换等方法,对该对称矩形环栅NMOS器件进行建模,给出了其等效宽长比的计算模型。在0.18 μm BCD工艺下进行流片,并对不同尺寸下直栅MOS器件和环栅MOS器件进行辐照对比测试。测试结果表明,对称矩形环栅NMOS器件的等效宽长比计算模型的计算误差可低至5%。辐照总剂量10 kGy条件下,对称矩形环栅NMOS器件的关态泄漏电流仍可维持在一个很低的量级,表现出良好的总剂量效应加固性能。 相似文献
5.
本文以电路的二分性定理在射频/微波技术领域的演变为基础,引出射频/微波对称网络的奇偶模分析方法,并以二分性定理和奇偶模分析法的导出公式的应用为例,说明典型的单、双对称电路和射频/微波对称网络网络参量的简单推导过程.结果表明,采用二分性定理和奇偶模分析法导出的对称电路和射频/微波对称网络的阻抗和散射参量与常规方法所得的结果完全相同. 相似文献
6.
7.
8.
论述了纵向对称双硅栅薄膜 MOSFET的等电位近似模型的研究 ,通过对该器件建立泊松方程 ,并利用在阈值电压附近硅膜中的等电位近似 ,得到了这种对称双硅栅 MOSFET器件的电流模型 ,并在不同参数下对该模型进行了模拟 ,最终得到 Ids-Vg 曲线 相似文献
9.
10.
11.
12.
13.
14.
利用球背投影法对理想导体目标成像 总被引:3,自引:0,他引:3
本文将CT原理和雷达转台成像原理引入到近场微波成像领域。作为CT中背投影响的推广,给出了球背投影的概念,进而提出了由散射近场重建理想导体目标轮廓的球背投影法及其实现算法,计算机模拟结果表明该方法是近场微波成像系统的一种有效方法。 相似文献
15.
针对转台模式的这场微波成像进行了深入研究。首先给出了转台模式下图像函数(描述目标的几何特征)与球投影的积分变换关系,并导出了图像函数的精确解。然后从线性系统的角度出发,研究了理想情况和实际情况下转台模式近场微波成像的分辨特性,理想情况下成像系统的点扩散函数(PSF)就是狄拉克-函数。PSF的数值模拟结果表明:实际情况下,扫描频带越宽分辨率越高。 相似文献
16.
Microwave modeling and validation in food thawing applications 总被引:1,自引:0,他引:1
Tim Tilford Ed Baginski Jasper Kelder Kevin Parrott Koulis Pericleous 《The Journal of microwave power and electromagnetic energy》2007,41(4):30-45
Developing temperature fields in frozen cheese sauce undergoing microwave heating were simulated and measured. Two scenarios were investigated: a centric and offset placement on the rotating turntable. Numerical modeling was performed using a dedicated electromagnetic Finite Difference Time Domain (FDTD) module that was two-way coupled to the PHYSICA multiphysics package. Two meshes were used: the food material and container were meshed for the heat transfer and the microwave oven cavity and waveguide were meshed for the microwave field. Power densities obtained on the structured FDTD mesh were mapped onto the unstructured finite volume method mesh for each time-step/turntable position. On heating for each specified time-step the temperature field was mapped back onto the FDTD mesh and the electromagnetic properties were updated accordingly. Changes in thermal/electric properties associated with the phase transition were fully accounted for as well as heat losses from product to cavity. Detailed comparisons were carried out for the centric and offset placements, comparing experimental temperature profiles during microwave thawing with those obtained by numerical simulation. 相似文献
17.
《Microwave Theory and Techniques》1963,11(4):263-264
A sketch of a novel broad-band microwave discriminator is shown in Fig. 1. The device utilizes a pair of symmetric 3-db hybrids joined by unequal lengths of transmission line. The difference between line lengths is represented as a frequency dependent phase difference /spl phi/. 相似文献
18.
19.
一种去嵌入射频测量技术 总被引:1,自引:0,他引:1
去嵌入是一种射频微波精确测量技术。本文介绍了一种新型的去嵌入测量技术。该方法只需要一个对称的直通微带结构就能完成去嵌入。最后利用该方法对0603封装的电感进行了测量,并提取了精确测量后的电感模型。结果表明本去嵌入方法可以应用于射频PCB上器件模型的精确测量和模型提取。 相似文献
20.
J. M. Owens J. H. Collins R. L. Carter 《Circuits, Systems, and Signal Processing》1985,4(1-2):317-334
A need for microwave signal processing components ranging from simple delay lines to broadband, complex analog non-recursive transversal filters has led to the exploration of several solid-state technologies. Bulk acoustic delay lines lack spatial signal tapping and have high insertion loss. Electromagnetic delay lines have high insertion loss, limited signal processing capabilities, and are bulky. Surface acoustic wave (SAW) devices offer excellent signal processing capabilities at VHF/UHF but suffer from excessive loss at microwave frequencies and the requirement for transducers of sub-micron linewidths. However, a signal processing technology based on magnetostatic waves (MSW) propagating on epitaxial yttrium iron garnet (YIG) is emerging to fill microwave signal processing requirements. This paper summarizes the characteristics and status of magnetostatic waves and devices based on MSW, and initial experimental studies of the application of MSW devices to systems, and presents a survey of other potential areas of MSW device applications. 相似文献