校准六端口反射计的新技术

作者对Hoer博士(1979)的四标准负载校准方法进行了改进,并将该方法与李世鹤博士(1982)的四短路器法结合使用,提出一种新的六端口反射计校准方法;它既有李氏法快速、简单的优点,又兼有Hoer法精度高的长处。作为示例,本文给出了新方法在我们研制Ku波段六端口反射计中运用的效果。     

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。     

多端口反射计的任意相位单位矢量五点校准法的改进

本文对多端口反射计的任意相位单位矢量五点校准法作了改进。根据多端口反射计响应方程的对称性,本文提出用同一求解过程确定两个系数复常数。对四态四端口反射计进行的校准表明,改进后的方法与改进前的方法计算结果完全一致,但改进后的方法程序编制更简单、实现更容易。     

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。     

功率计误差对六端口反射计精度影响的蒙特卡洛计算机模拟

功率计检测误差对六端口反射计的测量精度影响是非常大的。对于一个实际的反射计,由于整个系统比较复杂,用常规方法很难估算出功率计检测误差对反射计的测量精度的影响。本文引用了一种概率统计方法蒙特卡洛(Monte Carlo)法对六端口反射计的测量精度进行数值计算。并且用一个X波段的六端口反射计作为例子,给出了计算结果与直方图。用这种方法可以为六端口反射计的合理设计提供依据。     

六端口反射计的自校准方法

本文应用六端口电路的基本原理,导出了六端口反射计的自校准方程,并利用优化方法讨论了几种不同的自校准方法。通过计算机模拟和实际测试系统的实验,证明了这些方法均可获得较为满意的结果。     

四对反相单位矢量变换分离法

本文利用阿波罗纽斯定理(Apollonius law)●所反映出来的对称性,阐明了多端口广义反射计的工作原理,并给出了求解复数反射系数的四对反相单位矢量变换分离法。     

一种用于大信号测试的矢量校准快速修正方法

大信号测试系统是评估GaN功率器件的非线性特性的重要手段,而精准的矢量校准是获得稳定可信测试数据的第一步。为了解决毫米波频段矢量校准易随时间增加而失效的难题,对不同的校准方法进行了讨论,并以直通-反射-匹配负载(TRM)校准方法为基础,对校准过程中的误差系数随时间变化的趋势进行了数据分析,提出了一种可以实时快速修正校准模型中误差系数的方法。采用这种方法,失效的校准状态可以在1 min内得到快速修正而恢复初始校准状态;矢量校准的时间稳定度与传统方法相比,可延长10倍以上。该方法有力地保证了大信号测试中数据的一致性,可广泛应用于器件建模和电路设计等领域。     

多状态反射计技术

本文讨论了多状态测试技术,并将它与多端口测试技术进行了比较,通过分析给出了多状态测试时的功率关系。最后给出了一个工作在毫米波波段的多状态反射计实例,所得结果是令人满意的。     

W波段六端口反射计的设计,校正与误差分析

介绍了W波段六端口反射计的结构、设计、校正及误差分析.用广义谐振腔的概念优化设计了波导结;对检波器采用多种匹配措施;用比对法校正了该反射计;介绍了一种用最小二乘法测双口网络参数的方法,它具有测试方便,计算简单,精度高的优点;最后对精度作了分析.     

Multistate reflectometer

A detail discussion on the multistate technique and comparison of the multistate technique with the multiport technique are given. The relation between the output power and reflection of the device under test is shown. An experiment millimeter wave multistate reflectometer is given and its measuring results are satisfactory.     

The Calibration and Performance of a Microstrip Six-Port Rdlectometer

The calibration and performance of a microstrip six-port reflectometer consisting of only one six-port coupler is discussed. The positions of the centers of the impedance-locating circles are determined from the calibration constants and their frequency behavior is illustrated. The results of measuring some terminations by the reflectometer and two HP network analyzers are compared within the frequency range from 0.5 GHz to 8 GHz. From this comparison tke useful bandwidth of the reflectometer is found to be from 0.5 GHz to 5.5 GHz.     

Calibration of Multiport Reflectometers by Means of Four Open/Short Circuits

This paper presents a simple method for calibrating any practical multiport reflectometer by means of four reflection standards with known complex reflection coefficients. It is shown that these four standards can be such that their reflection coefficient modulus = 1. Computer simulation proves that no singularity appears for both ideal and nonideal five- and six-port reflectometer in a wide range of phase distribution of reflection coefficients. A group of calibration results for a practical simple six-port is fisted to show this calibration procedure; by the use of these calibrated network parameters, some measurement results are presented and compared with the values obtained at the National Bureau of Standard, U.S.A. Both computer simulation and experimental results show that the numerical singularities which may be encountered in multiport calibration procedures are not an intrinsic properties of multiport but from related mathematical treatment.     

Réalisation ďun Réflectomètre a Six Accès Dans la Bande de Fréquences Millimétriques W (75-110 GHz)

This paper presents a six-port reflectometer in the W frequency band (75-110 GHz). Schottky diodes, operating in AC detection mode, are used as power detectors. A linearization procedure is used to improve the measurement accuracy. The six-port calibration is performed with two standards. Finally, the experimental results are compared with those obtained with other network analyzers in this frequency band.     

Dual-Mode Reflectometer for Measuring Microwave Magnetic Kerr Effect in Semiconductors

The "dual-mode reflectometer" is a device with which one can measure the relative off-diagonal terms of the tensor reflection coefficient of a hybrid mode composed of two degenerate, mutually perpendicular, independent modes. It differs from the conventional "single-mode reflectometer" in that it permits launching elliptically polarized waves of arbitrary orientation and ellipticity into the main (circular or square) waveguide and observing the orientation and ellipticity of the wave reflected by the load. This paper describes application of the dual-mode reflectometer to measurement of the magnetic Kerr effect in semiconductors. The accuracy and resolution of the apparatus is demonstrated with measurements of germanium and silicon at x band. A scattering matrix analysis is given which describes the measurement and calibration procedure.