用六端口和开口同轴线测量介电常数的一种校准方法

本文提出了一种六端口测量介电常数的校准方法，该方法将六端口和开口同轴线两次校准合为一次，特别适合于介电系数的在线测量。     

双六端口网络分析仪校准与测量的一种新方法

本文利用波的叠加原理,把已知的单六端口反射仪的四标准校准法应用到双六端口网络分析仪上,提出了双六端口网络分析仪校准与测量的一种新技术。     

多端口反射计的任意相位单位矢量五点校准法及误差分析

本文讨论用五个任意相位的单位矢量来校准多端口反射计的方法。该方法使用简便,且适用于扫频测试。对于各类多端口反射计的校准、测量和误差分析,均是一种十分有效的方法。另外,本文利用该方法完成了对多端口反射计和误差分析,得到定量分析结果。     

一种用于氮化镓晶体管建模的TRL校准方法

直通-反射-延迟线(TRL)校准相对于短路-开路-负载-直通(SOLT)校准是一种更加准确且易于实现的校准方法,尤其适用于二端口及多端口的非同轴测量。文中针对Wolfspeed公司的氮化镓晶体管CGH40010F的S参数测量问题,分析讨论了TRL校准在网络分析仪中的误差盒模型,在此基础上设计制作了一套TRL校准件,其工作频率范围为1～6 GHz,在此频段内直通和延迟线均达到S_ii(i=1,2)幅值小于-15 dB,S_ij(i,j=1,2;i≠j)幅值大于-0.8 dB;将该校准件特性指标内置到矢量网络分析仪中进行校准测试,实测结果表明,经过TRL校准后的氮化镓晶体管小信号S参数与官方数据手册中一致,验证了该校准测量方法及据此设计制作的TRL校准件是有效的。     

校准件端口尺寸测量方法及不确定度分析

文章简单介绍校准件端口尺寸的测量方法,主要分析了影响其测量不确定度的各个因素,并对引入的测量不确定度的各分量进行评定,给出完整的端口尺寸的测量结果。     

非理想校准件对S参数测量结果的影响

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。     

流图法在光探测器芯片高频特性测量校准上的应用

在采用光调制法测量光探测器芯片高频响应特性的过程中,测试系统往往忽视光调制器响应、高频探针衰减以及端口间失配等误差中的一项或几项.为了降低校准不完善对结果造成的误差,文中提出了基于信号流图的系统校准分析方法,考虑了各种频响误差及端口间失配的影响,推导出校准公式.利用该法对一种光探测器的典型测试系统--基于LCA(lightwave component analyzer)的测试系统做了进一步校准分析,在130MHz～20GHz范围内,测量了一种新型光探测器的高频响应参数S21,结果表明经流图法校准的S21参数比仅使用原有校准算法有明显改善,证明了该方法的可行性.     

SOLT校准方法及其在射频测量中的应用

分析了矢量网络分析仪测试系统的误差来源,给出二端口SOLT校准的12项误差模型,由此推导了待测元件的真实S参数,并且详细讲述了SOLT校准件的制作方法,确定出开路件的边缘电容。最后,使用自制的PCB夹具测量了0603封装的电感和电容．对校准前后的测量数据进行了对比、分析,并成功地提取了封装后的模型参数,结果证明该方法可以用于射频夹具测量的校准。     

混合信号测试系统S参数测量的校准

混合信号测试系统一般用于射频或微波电路S参数的测量,但由于厂家无完整的校准方案和软件支持,提供的校准方案只能校准到特定的测量端面,实际测试时端口需要延伸;并且,系统将引入较大的失配和损耗误差,测量结果不能反映器件的真实性能指标,高精度测量受限。以业界主流的大型射频混合信号测试系统LTX-MX为例,分析S参数测量时的系统误差模型和校准方法,为测试工程师使用大型测试系统准确测量S参数提供了一种校准方案,并为后续的高精度测量提供了可行性。     

流图法在光探测器芯片高频特性测量校准上的应用

在采用光调制法测量光探测器芯片高频响应特性的过程中,测试系统往往忽视光调制器响应、高频探针衰减以及端口间失配等误差中的一项或几项.为了降低校准不完善对结果造成的误差,文中提出了基于信号流图的系统校准分析方法,考虑了各种频响误差及端口间失配的影响,推导出校准公式.利用该法对一种光探测器的典型测试系统--基于LCA(lightwave component analyzer)的测试系统做了进一步校准分析,在130MHz～20GHz范围内,测量了一种新型光探测器的高频响应参数S21,结果表明经流图法校准的S21参数比仅使用原有校准算法有明显改善,证明了该方法的可行性.     

Determining the scattering-matrix elements and matching conditions for asymmetric microwave two-port networks

A relationship between the elements of the scattering matrix of an asymmetric microwave two-port network and its input and output impedances under open-circuit and short-circuit conditions are determined. Analytic expressions for the elements of the scattering matrix of reciprocal passive linear microwave two-port networks of various kinds—asymmetric, antisymmetric, and symmetric—have been obtained. A theorem of necessary and sufficient matching conditions for these two-port networks is formulated.     

Invariant Definitions of the Unloaded Q Factor (Short Paper)

Equations are presented for computing the unloaded Q factor of a microwave resonator embedded in an impedance-transforming lossIess, reciprocal two-port. Knowledge of the transformation properties of the two-port is not required.     

A new implementation of a multiport automatic network analyzer

A generalized multiport network analyzer implemented using commercially available hardware is presented. Measurement calibration is accomplished through a novel calibration procedure which requires only conventional standards used for two-port calibrations. The calibration theory accounts for the errors due to the signal switching network but does not systematically remove errors due to signal switching leakage between port pairs. The approach is verified on a three-port test set implementation, and the measuring system can be expanded to n ports with additional hardware in a straightforward manner. Experimental verification was carried out through measurement of one-, two-, and three-port devices connected to the test set ports in several different ways. Excellent agreement of the same corrected S-parameters measured at different test set ports was observed, and confidence in system accuracy is established through measurement of two-port verification standards     

基于组合联接双微波二端口网络的噪声分析

大多数微波电路可以用一个二端口网络或者多个二端口网络相互联接的方法进行模拟和分析，二端口网络方法比节点分析法更加简洁，且便于快速计算。基于简单联接二端口网络的微波电路噪声分析并提取噪声参数有很重要的应用价值。本文将对两种组合联接的微波二端口网络进行噪声分析，并给出相应的结论。     

Computer-Aided Determination of Microwave Two-Port Noise Parameters

The least-squares fit of measured noise figures as a function of source admittance is an accurate and rapid method also convenient from the experimental point of view, to determine linear two-port noise parameters. However, to avoid the erroneous results often obtained by experimenters, this paper presents some criteria to be followed in choosing the proper source admittances. In order to apply the method to microwave two-ports, a relationship relating noise parameters in a linearized form is introduced. The analytical developments are in terms of effective input noise temperature of the two-port. Experimental. results for a microwave transistor are also reported as a function of experimental redundancy.     

Measurement of magnitude and phase of harmonics generated innonlinear microwave two-ports

A method for simultaneously measuring the magnitude and phase of the harmonics generated by a microwave two-port is reported. The two-port under test is driven with a sinusoidal microwave signal strong enough to force it into nonlinear operation. Its output harmonics are measured in the frequency domain with a setup that includes a vector network analyzer. For phase calibration at the harmonic frequencies, a millimeter-wave Schottky diode is used as a reference device. The system allows the measurement of harmonics with a phase accuracy of about ±10° at 20 GHz (referred to f₁=5 GHz). It can be built for any frequency (<40 GHz) at which a vector network analyzer and a suitable signal generator with multiplier are available. For low-amplitude harmonics, higher sensitivity compared to time-domain measurements with a sampling scope results in better measurement accuracy. The accuracy should improve further if the nonideality of the diode reference circuit is characterized more precisely     

A unified mathematical approach to two-port calibration techniquesand some applications

A rigorous mathematical treatment of microwave network analyzer calibration and de-embedding procedures for the two-port error network representation is used in order to explain current calibration techniques in a succinct and homogeneous manner. It is demonstrated that the essence of through-delay de-embedding techniques consists in the use of two known two-port calibration standards to obtain pairs of similar matrices for the input and output error adapters. Once the characteristic vectors for these matrices are obtained, a number of different approaches can be used in order to solve for the scaling constants     

YIG magnetoelastic two-ports for microwave pulse compression

By coupling to the magnetoelastic spin-wave mode in YIG crystals with microwave acoustic transducers, dispersive two-port components can be realized. Preliminary characteristics of such a device employing a CdS shear transducer are reported in the UHF range. Elastic coupling losses, spin-wave limiting characteristics, dynamic range, and delay dispersion linearity of YIG devices are discussed for microwave pulse compression applications.     

NOVA (Network Optimization Via Adjoints) (Computer Program Descriptions)

Least pth optimization of reflection coefficients and/or transducer gain of two-port microwave networks.     

Stripline dual-mode ring resonators and their application tomicrowave devices

This paper describes the fundamental properties of two orthogonal resonant modes within stripline ring resonators and their application to microwave devices. There are two principal methods for application of ring resonators, the first is by using two-port devices and the second four-port devices, in the case of two-port configurations, dual-mode filters using coupling between two degenerate modes have been studied as typical applications. In this paper, new methods for the coupling of two modes and their applications to practical devices, are proposed, and then experimental results for proof of the new structures are presented. Four-port configurations, which make use of two resonant modes as being independent or having no coupling between them, have a wider range of application to microwave devices. Microwave circuits such as tuned amplifiers and oscillators with novel structures are proposed, and their excellent characteristics are demonstrated. The experimental results obtained in this study on two and four-port devices make it clear that dual-mode ring resonators have great potential for application to various microwave devices