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有源器件的端口反射系数是器件的主要参数,端口反射系数的大小直接影响信号的输出功率。为实现有源器件在“射频开”状态下端口反射系数的测量,开展了阻抗调谐器法和网络分析仪频率偏移法的源端口反射系数测量方法研究,并针对信号源和放大器开展了相应的实验。测量结果表明,10 dBm输出时2种方法测得反射系数模值的差别小于0.06,相位变化差别优于10°,为有源器件端口反射系数的测量提供了可行的方法。 相似文献
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本文描述了采用单六端口微波测量技术建立的频段为100-1000MHz范围内的同轴射频高功率复反射系数和功率校准装置的设计、校准及性能。 相似文献
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研究了测量复反射系数和传输系数的最佳五端口网络理论,叙述了一个紧凑的波导方案,能在整个波导频带内通过测量两个参考功率电平确定复反射系数和传输系数。 相似文献
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采用频谱分析仪测量信号源功率电平及校准不确定度 总被引:2,自引:0,他引:2
文章提出了采用频谱分析仪测量信号源输出功率电平的实现方法,并对该方法的不确定度进行了分析,解决了在没有接收杌的情况下射频信号源功率电平检定的问题. 相似文献
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提出了一种在微波频域测量聚合物样品薄片复介电常数的方法,它利用自动测量线测试系统测量出电压驻波比和相角,然后采用级数各阶次展开方法,由反射系数推导出复介电常数.级数低阶次方法求解厚度较大的被测样品复介电常数时,为确保结果具有较高的精确度,要求测量频率不超过1.5GHz.为了克服这种测量频域的局限性,可采用级数高阶次展开方法来求解复介电常数.用级数展开方法测量聚苯乙烯、多乙酸乙烯酯和聚亚胺酯的复介电常数值,结果与真实值相近,可以和传输/反射法相媲美. 相似文献
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A Vector Network Analyzer(VNA) can be used to identify oscillation frequency of a signal source with moderate or low Radio Frequency(RF) power if certain care is taken according to experimental results. Unlike reported in the literature that a resonant peak of measured absolute value of reflection coefficient greater than 1 that corresponds to an oscillation frequency, we report that by observing the magnitude change of one-port reflection coefficient across the entire swept frequency range, a sudden peak or a dip corresponds to an oscillation frequency, this is more accurate than other reports. In addition, using modern VNA as a signal detection method can significantly reduce measurement time and increase measurement accuracy to VNA capability for developing emerging signal generating devices at early stage, especially for planar, large quantity and operating in a wide frequency range. 相似文献
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《Microwave Theory and Techniques》1982,30(5):667-670
An automatic network analyzer (ANA) based on a 5-port reflectometer is presented. The measuring circuit consists of a slotted waveguide with sliding probe. A group of three fixed probes may be used instead. A microwave source, frequency counter, and power meter are used all controlled by a desktop computer. The theory is simple and the algorithm for obtaining the complex reflection coefficient from experimental data is fast. Some results are given for measurements earned out at X-band frequencies. Successful measurement accuracy is achieved with relatively noncomplex hardware. Multioctave bandwidth operation is expected for the proposed technique. 相似文献
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针对复杂环境下的米波雷达低仰角测高问题,建立多径信号服从高斯分布源的阵列信号模型,提出一种广义约束多重信号分类(MUSIC)算法。该算法将多径信号作为约束,通过限制信号子空间包含多径导向矢量,来提高直达波的估计精确度。算法性能不受信号相干和地面反射系数的影响。与传统的测高算法相比,该方法在复杂反射地形下能有效进行目标高度估计。计算机仿真结果验证了该算法的可行性。 相似文献
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Tian Buning Tang Jiaming Liu Qizhong 《电子科学学刊(英文版)》2001,18(4):359-362
A novel method for precise measurement of complex reflection coefficient using a four-port reflectometer is presented. First, three new complex system constants are introduced, which depend only on the scattering parameters of the four-port reflectometer. Therefore, the stability of the reflectometer is greatly improved. Then, these complex system constants are used to determine the complex reflection coefficient T of the device under test by calibrating the reflectometer. Finally, a four-port reflectometer comprising a magic tee and a power detector is constructed and excellent experimental results are obtained. 相似文献
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辐射场测量是检验高功率微波系统输出指标的重要手段.随着高功率微波测量技术的发展,辐射场测量系统的稳定性和可靠性不断提高,作为完整测量结果重要组成部分的测量不确定度越来越受到关注.文章介绍了高功率微波辐射场功率密度测量方法及系统组成,建立了功率密度测量的数学模型,给出了高功率微波辐射场功率密度测量的主要不确定度来源.对检波器输入功率计算、接收天线有效面积校准、衰减环节校准及测量系统各环节连接失配等测量不确定度分量进行了分析,并给出了高功率微波辐射场功率密度测量不确定度的合成方法.本文给出的测量不确定度分析方法较为科学、操作性强,对完善高功率微波辐射场功率密度测量结果具有一定的指导意义. 相似文献
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A simple, compact, and low-cost three-probe microstrip impedance measuring scheme has been developed. The impedance of an unknown load can be determined by measuring the coupling power levels at the three probes. The algorithm, formulas, and bandwidth criteria developed are very simple and can be easily used. The power coupling is arbitrary, and no precise directional coupler is required. Using a switch, only one power meter is needed to detect the output power levels of the three probes. The phase information is obtained by amplitude measurement. A detailed analysis and calibration method are developed. The calibration is based on three known standards (a short, an open, and a matched load). The reflection coefficient is calculated from power measurements at three locations along a uniform line terminated by an unknown load. The operating frequency bandwidth depends on the selection of probe locations. A prototype device has been built at X -band 相似文献