Use of Microwaves for Nondestructive Material Inspection

1996 ◽  
Vol 430 ◽  
Author(s):  
B. R. Hokkanen ◽  
J. F. Lindsey
Keyword(s):  
Structural Integrity ◽  
Moisture Absorption ◽  
Surface Defects ◽  
Microwave Energy ◽  
Vector Network Analyzer ◽  
Network Analyzer ◽  
Scattering Parameters ◽  
Conductive Materials ◽  
S Parameter ◽  
Testing Tool

AbstractWideband S-parameter measurements have been used to investigate the properties of electrically non-conductive materials using a vector network analyzer. Using S21 scattering parameters, amplitude and phase shift measurements were taken for a variety of both homogeneous and heterogeneous materials. With these initial S-parameter measurements as a reference, surface defects were modeled on the test samples and the S-parameter measurements were reevaluated. The effect of varying levels of moisture absorption in certain materials was also investigated. The results of this study indicate that there is indeed potential for the use of a vector network analyzer as a nondestructive testing tool to evaluate the structural integrity and/or moisture content of electrically non-conductive materials through the transmission of microwave energy.

Accuracy Improvement for Scattering-Parameters Evaluating of Microwave Coplanar Probe Using One-Port Two-Tier Multi-TRL Calibration Method

2013 ◽  
Vol 333-335 ◽  
pp. 254-258 ◽  
Author(s):  
Hui Huang ◽  
Xin Meng Liu ◽  
Xin Lv
Keyword(s):  
Calibration Method ◽  
Vector Network Analyzer ◽  
Network Analyzer ◽  
Random Errors ◽  
Scattering Parameters ◽  
Accuracy Improvement ◽  
S Parameters ◽  
Improving Accuracy ◽  
System Errors ◽  
Residual Errors

This paper presents a method improving accuracy for evaluating S-parameters (Scattering-parameters) of MCP (Microwave Coplanar Probe). This method may be named one-port two-tier Multi-TRL (Thru-Reflect-Line) calibration method. It measures two-port devices only at one port of VNA (Vector Network Analyzer). It decreases the random errors caused of cable movements and connecting times. This method is implemented with coaxial OSL (Open-Short-Load) and on-wafer TRL calibration kit. It directly calculates and removes the residual errors caused of coaxial OSL calibration kit imperfection. It significantly reduced system errors by using on-wafer TRL calibration kit. To verify the effectiveness of the proposed method, the measured S-parameters up to 50GHz of MCP configured with GSG-100 are given and discussed.

scholarly journals Calibration-measurement unit for the automation of vector network analyzer measurements

2008 ◽  
Vol 6 ◽  
pp. 27-30
Author(s):  
I. Rolfes ◽  
B. Will ◽  
B. Schiek
Keyword(s):  
Vector Network Analyzer ◽  
Measurement Unit ◽  
Network Analyzer ◽  
Scattering Parameters ◽  
Calibration Standards ◽  
Calibration Measurement ◽  
Vector Network Analyzers ◽  
Network Analyzers ◽  
The One ◽  
User Friendly

Abstract. With the availability of multi-port vector network analyzers, the need for automated, calibrated measurement facilities increases. In this contribution, a calibration-measurement unit is presented which realizes a repeatable automated calibration of the measurement setup as well as a user-friendly measurement of the device under test (DUT). In difference to commercially available calibration units, which are connected to the ports of the vector network analyzer preceding a measurement and which are then removed so that the DUT can be connected, the presented calibration-measurement unit is permanently connected to the ports of the VNA for the calibration as well as for the measurement of the DUT. This helps to simplify the calibrated measurement of complex scattering parameters. Moreover, a full integration of the calibration unit into the analyzer setup becomes possible. The calibration-measurement unit is based on a multiport switch setup of e.g. electromechanical relays. Under the assumption of symmetry of a switch, on the one hand the unit realizes the connection of calibration standards like one-port reflection standards and two-port through connections between different ports and on the other hand it enables the connection of the DUT. The calibration-measurement unit is applicable for two-port VNAs as well as for multiport VNAs. For the calibration of the unit, methods with completely known calibration standards like SOLT (short, open, load, through) as well as self-calibration procedures like TMR or TLR can be applied.

MIXED CHARACTERISTIC OF S-PARAMETERS OF DIFFERENTIAL STRUCTURES

2021 ◽  
pp. 74-78
Author(s):  
Т.С. Глотова ◽  
Д.В. Журавлёв ◽  
В.В. Глотов
Keyword(s):  
Transmission Lines ◽  
Mixed Mode ◽  
Mode Conversion ◽  
Vector Network Analyzer ◽  
Network Analyzer ◽  
Circuit Performance ◽  
Reflected Waves ◽  
Linear Networks ◽  
S Parameter ◽  
S Parameters

Различные типы СВЧ-устройств можно описать с помощью падающих и отражённых волн, которые распространяются в подключенных к ним линиях передач. Связь между этими волнами описывается волновой матрицей рассеяния или матрицей s-параметров. Оценка дифференциальных структур необходима для обеспечения оптимальных характеристик схемы. Комбинированные дифференциальные и синфазные (смешанные) параметры рассеяния (s-параметры) хорошо адаптированы для точных измерений линейных сетей на радиочастотах. Представлено преобразование между стандартными s-параметрами и s-параметрами смешанного режима, также описано графическое сравнение графиков стандартных и смешанных потерь s-параметра. S-параметры смешанного режима, полученные с помощью описанного метода, имеют хорошее согласие для возбудителя и реакции с одним и тем же режимом (общий или дифференциальный) и небольшую вариацию с разными режимами. Была изготовлена дифференциальная структура, которая измеряется с помощью двухпортового векторного анализатора цепей и четырехпортового анализатора цепей смешанного режима. Для прогнозирования поведения параметров смешанного режима с использованием традиционного двухпортового векторного анализатора цепей можно применить метод преобразования режимов, однако четырехпортовый анализатор цепей смешанного режима по-прежнему необходим для точного измерения влияния режима преобразования в реальные интегрированные дифференциальные тестовые структуры Various types of microwave devices can be described using incident and reflected waves that propagate in the transmission lines connected to them. The relationship between these waves is described by the scattering wave matrix or the S-parameter matrix. Evaluation of differential structures is necessary to ensure optimal circuit performance. The combined differential and common-mode (mixed) scatter parameters (s-parameters) are well suited for accurate measurements of linear networks at radio frequencies. We present the transformation between standard s-parameters and mixed-mode s-parameters, and a graphical comparison of graphs of standard and mixed s-parameter losses is also described. S-parameters of the mixed mode, obtained using the described method, have good agreement for the pathogen and the reaction with the same mode (general or differential) and little variation with different modes. We fabricated and measured a differential structure with a two-port vector network analyzer and a four-port mixed-mode network analyzer. Mode conversion can be used to predict the behavior of mixed-mode parameters using a traditional 2-port vector network analyzer, but a four-port mixed-mode network analyzer is still required to accurately measure the effect of conversion mode on real integrated differential test structures

scholarly journals Methods for the calibrated measurement of the scattering parameters of planar multi-port devices

2007 ◽  
Vol 5 ◽  
pp. 439-445 ◽  
Author(s):  
I. Rolfes ◽  
B. Schiek
Keyword(s):  
Error Correction ◽  
Measurement System ◽  
Systematic Errors ◽  
Microwave Circuits ◽  
Calibration Procedure ◽  
Vector Network Analyzer ◽  
Switching Network ◽  
Network Analyzer ◽  
Scattering Parameters

Abstract. In this article, the error-corrected determination of complex scattering parameters of multi-port devices by means of a 2-port vector network analyzer is presented. As only two ports of the device under test can be connected to the analyzer ports at a time, the remaining device ports have to be terminated by external reflections. In order to measure the scattering parameters of the DUT without the influence of systematic errors and of the external terminations, an error correction has to be performed besides the calibration. For this purpose, the application of the multi-port procedure is presented. This method has the advantage, that the external reflective terminations can be chosen arbitrarily. Furthermore, these terminations can be unknown except for one. An automatized measurement system based on a switching network is shown, which is optimized for the measurement of planar microwave circuits. An error model for the description of the measurement setup as well as a calibration procedure for the elimination of the systematic errors are presented.

scholarly journals An Error Correction Procedure for Multi-Port Measurements at High Frequencies

2005 ◽  
Vol 3 ◽  
pp. 59-64
Author(s):  
I. Rolfes ◽  
B. Schiek
Keyword(s):  
Error Correction ◽  
Short Circuit ◽  
Correction Method ◽  
Frequency Characteristics ◽  
Vector Network Analyzer ◽  
Network Analyzer ◽  
Correction Procedure ◽  
Scattering Parameters ◽  
High Frequencies ◽  
Port Device

Abstract. The multi-port method for the measurement of the scattering parameters of multi-ports with the help of a vector network analyzer (VNA) with only two measurement ports is presented. For the measurements only two ports of the N-port device can be connected to the two ports of the VNA at a time. The remaining N-2 ports of the device under test (DUT) are connected to external terminations. As these external terminations might be mismatched, the measured scattering parameters depend on the reflective characteristics of the terminations. An error correction becomes necessary in order to calculate the effective scattering parameters of the DUT (Tippet and Speciale, 1982; Lu and Chu, 2003). In contrast to the correction method of Tippet and Speciale (1982), the multi-port method has the advantage, that the external terminations can be chosen arbitrarily. Thus, a realization as an open or short circuit is possible as well. Furthermore, the terminations can be unknown except for one, similar to self-calibration procedures of VNAs. This helps to improve the accuracy of the measurements, because the inconsistency problem due to a slightly erroneous knowledge of the frequency characteristics of the terminations can be eliminated.

Reconfigurable SDM Optical Vector Network Analyzer

2014 ◽  
Author(s):  
Joel Carpenter ◽  
Benjamin J. Eggleton ◽  
Jochen Schröder
Keyword(s):  
Vector Network Analyzer ◽  
Network Analyzer

scholarly journals Wideband Active Load–Pull by Device Output Match Compensation Using a Vector Network Analyzer

2021 ◽  
Vol 69 (1) ◽  
pp. 874-886
Author(s):  
Alberto Maria Angelotti ◽  
Gian Piero Gibiino ◽  
Troels S. Nielsen ◽  
Dominique Schreurs ◽  
Alberto Santarelli
Keyword(s):  
Vector Network Analyzer ◽  
Network Analyzer ◽  
Active Load ◽  
Load Pull
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