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TRL校准方法是矢量网络分析仪(Vector Network Analyzer,VNA)校准的常用方法之一,它通过对直通件、反射件和传输线3个标准件的测量,经过一系列计算获取各误差项的值。但是在实际测量中,这些校准件并不能在整个频带范围内具有理想的特性,从而在实际测量时会引起被测件S参数的测量不确定度。对于使用日益广泛的多端口VNA而言,测量不确定度的分析比二端口VNA更为复杂,目前对其开展的研究还不够广泛深入。文章以四端口VNA为例,对TRL校准过程中由非理想标准件引起的被测件的S参数测量不确定度进行研究。首先,运用广义节点的思想将四端口VNA的S参数测量不确定度用矩阵形式表示,再运用广义TRL校准方法,求得各误差项及其偏移的值,最终求得灵敏度系数的解析式,它可以对四端口VNA进行S参数测量不确定度的B类评估。 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 diversity imaging using six-port reflectometer 总被引:1,自引:0,他引:1
Hsin-Chia Lu Tah-Hsiung Chu 《Microwave Theory and Techniques》1999,47(1):84-87
A microwave diversity imaging system conventionally uses a vector network analyzer (VNA) to directly measure the object scattered field (amplitude and phase) over a selected frequency range and viewing angles, then reconstructs the scattering object characteristic function through two dimensional Fourier inversion. In this paper, we present a cost-effective microwave diversity imaging system using a six-port reflectometer, which measures four amplitude (or power) values to acquire the object scattered field indirectly. One can then eliminate the coherent detectors in a VNA. The calibration procedure for this microwave diversity imaging measurement is also described. Experimental results of three types of scattering objects, a metallic cylinder, four distributed line scatterers, and a 72:1 scaled B-52 aircraft model, are presented using the described six-port microwave imaging system 相似文献
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虽然目前校准算法已趋成熟,但由于随机误差和剩余系统误差等的存在,矢量网络分析仪(Vector network analyzer,VNA)的测量结果不可避免地会有一定的不准确性.而现有的矢网测量不确定度评估算法中往往只考虑剩余系统误差,忽略了系统线性性能、线缆状态以及测试环境等因素.本文同时考虑了校准后剩余系统误差、系统非线性误差,随机误差及测量环境等因素,建立了整机测量不确定度模型,实现了矢量网络分析仪整机测量不确定度的评估.与现有矢网不确定度评估算法相比,本算法考虑的误差因素更为全面,评估结果更为可靠.利用误差上限传递思想推导出商用VNA散射参数测量不确定度评估公式,并提供了相应的参数获取方案.应用该算法对安捷伦8753ES矢量网络分析仪进行测量不确定度评估,并与安捷伦提供的技术数据进行对比,其结果数据吻合良好. 相似文献
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ABSTRACTReflection coefficient measurement is one of those fundamental methods for determining the performance of radar absorber materials, and reflections due to these measurements are originated from the discontinuities in the measurement system and they result in error. In this paper, a new technique for the calibration of the scalar reflection coefficient measurements in the frequency range of 3–18 GHz in a portable two-sectioned metallic chamber is being proposed for use in quick laboratory tests with reasonable error (redacted error). Calibration measurements are performed by two calibration standards in frequency domain and transformed to time domain for further calculation. Proposed technique exhibits a good agreement with the theoretical values for especially in compact chambers where plane-wave conditions are not fully satisfied, and it is not in need of any complex time gating process. Furthermore, it does not require considering the phase differences which occurs at the measurement plane, providing a cheap and faster solution, reducing time and complexity in characterization of radar absorber materials. This technique with the mentioned test set-up could supply scalar reflection coefficient measurements with overall 0.55 dB error level and useful for practical applications where high level of accuracy is not required. 相似文献
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本文简单介绍量值溯源的概念,主要阐述用于矢量网络分析仪的机械校准件所需溯源的量值,并给出其溯源图,以确保校准件、矢量网络分析仪以及被测微波件的量值准确性。 相似文献
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Accurate dielectric properties are of great importance for the design and fabrication of the input and output windows in vacuum electronic devices. A reflection-type hemispherical open resonator (RTHOR) was designed through theoretical analysis and numerical simulation and also was utilized to measure the dielectric properties of the windows material sapphire. Compared with the two ports measurement, a simplified measurement system to obtain the dielectric performance was proposed and the RTHOR with only one coupling aperture was directly connected to a W-band vector network analyzer (VNA). The material properties can be easily calculated through the VNA measured port reflection coefficient (S11) resonant curve. Investigation shows that the permittivity and the loss tangent of the measured sapphire, which is used to construct the input and output window, is respectively about 9.40 and 1.80?×?10?4 at room temperature in W-band, which agree well with the reported results. Measured results also show that the simplified measurement system can provide a high accuracy for the measurement of low-loss dielectric in a relatively convenient way. 相似文献
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《Microwave Theory and Techniques》2006,54(9):3583-3593
An improved vector network analyzer (VNA) calibration approach is demonstrated that utilizes planar lumped short-open-load-thru standards and achieves accuracy comparable to thru-reflect-line (TRL) at high frequency, without the commonly occurring errors in TRL at low frequency. The approach relies on complex load and thru models for coplanar waveguide and microstrip standards that are not currently available in typical VNA firmware. It is shown that the RF performance changes due to variations in fabrication of load can be addressed by “calibrating” or adjusting the load model with the measured dc resistance for a particular load. Good results are shown for a wide range of substrates (GaAs, alumina, and FR-4) and frequencies to 110 GHz. 相似文献
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针对国内军用及民用各类型天线及目标特性测量常用的紧缩场静区平面波幅相性能现场校准需求,开展了0.3~110 GHz紧缩场现场校准系统的优化设计。研制了微波幅相收发系统、一体化接收探头天线和八自由度、高精确度可移动大型极坐标扫描设备(半径3 m,平面度均方根值0.04 mm),完成了大型紧缩场静区性能校准系统的研制。利用某航天单位的紧缩场对系统性能进行了现场试验验证,结果表明,研制的校准系统功能强,指标高,可以满足各类型紧缩场校准需求。 相似文献
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借鉴矢量网络分析仪采用标准校正件的方法,提出了一种简单、方便的干涉仪测向低系统误差相位校正方案,通过引入标准功分器作为校准件,来修正校正源通道支路各通道间的不平衡性,最终能够有效消除校正源支路各通道间的固有相差,从而提高系统测向精度.最后,对实现方法进行了定性分析. 相似文献
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De Roest D. Ymeri H. Vandenberghe S. Stucchi M. Schreurs D. Maex K. Nauwelaers B. 《Electron Device Letters, IEEE》2002,23(2):103-104
Frequency dependent measurements of scattering (S) parameters using a vector network analyzer (VNA) have been performed on IC interconnects on a lossy silicon substrate. The multiline calibration method has been used to perform the de-embedding of the line parameters, from which the line inductance is extracted. A highly accurate closed-form approximation for frequency-dependent impedance per unit length of a lossy silicon substrate for IC interconnects has been used to compare with the measurements performed 相似文献
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S. T. Han E. N. Comfoltey M. A. Shapiro J. R. Sirigiri D. S. Tax R. J. Temkin P. P. Woskov D. A. Rasmussen 《Journal of Infrared, Millimeter and Terahertz Waves》2008,29(11):1011-1018
We report the measurement of small losses in transmission line (TL) components intended for high-power millimeter-wave applications. Measurements were made using two different low-power techniques: a coherent technique using a vector network analyzer (VNA) and an incoherent technique using a radiometer. The measured loss in a 140 GHz 12.7 mm diameter TL system, consisting of 1.7 m of circular corrugated waveguide and three miter bends, is dominated by the miter bend loss. The measured loss was 0.3?±?0.1 dB per miter bend using a VNA; and 0.22?±?0.1 dB per miter bend using a radiometer. Good agreement between the two measurement techniques implies that both are useful for measuring small losses. To verify the methodology, the VNA technique was employed to measure the extremely small transmission loss in a 170 GHz ITER prototype TL system consisting of three lengths of 1 m, 63.5 mm diameter, circular corrugated waveguide and two miter bends. The measured loss of 0.05?±?0.02 dB per miter bend may be compared with the theoretical loss of 0.027 dB per miter bend. These results suggest that low-power testing of TL losses, utilizing a small, simple TL system and a VNA, is a reliable method for evaluating performance of low-loss millimeter-wave TL components intended for use in high-power applications. 相似文献
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首先从网络分析仪的测量体系结构入手,分析测量过程中的误差来源与描述方法,给出相应的误差校正方法的理论公式。并实测了宽带、低损耗器件在两种状态下的测试差异。最后,给出误差校正方法的校正结果与分析讨论。 相似文献
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We obtain a one-to-one relation between the shape and orientation of a convex compact planar set and a complex-valued reflection coefficient (Schur (1917) parameter) sequence, such that (1) the reflection coefficient magnitudes are less than or equal to one, (2) if any reflection coefficient has a magnitude equal to one, then all subsequent reflection coefficients are equal to zero, and (3) the first reflection coefficient is equal to zero. Three additional independent parameters specify the position of the set in the plane, and the size of the set (specifically its circumference). For a finite duration reflection coefficient sequence, if the last nonzero reflection coefficient has a magnitude that is less than one, then the boundary of the set is an infinitely differentiable convex curve. The boundary is a convex polygon if and only if the magnitude of the last reflection coefficient is equal to one; the number of sides of the polygon is equal to the index of the last reflection coefficient. Almost all planar convex compact sets have reflection coefficient sequences of infinite duration. Such sets can be accurately approximated with convex compact sets that are generated from relatively small numbers of reflection coefficients. 相似文献
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介绍了测试电波暗室墙壁反射电平的两种方法,既电压驻波比法(VSWR)和基于矢量网络分析仪的改进电压驻波比法(AVSWR),并对这两种方法进行了比较,给出了每种方法的优缺点。 相似文献
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《Vehicular Technology, IEEE Transactions on》2008,57(6):3381-3392