Методика измерения потерь в направляемых линиях передачи в миллиметровом диапазоне частот

An experimental method was developed to determine losses in microstrip and coplanar transmission lines for devices operating in the frequency range 77 - 81 GHz. The parameters of the scattering matrices are obtained using a vector network analyzer and frequency upconverters. The calculation of losses in waveguide-coplanar and coplanar-microstrip junctions is made.

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Simulation and Experimental Study of the Near Field Probe in the Form of a Folded Dipole for Measuring Glucose Concentration

Applied Sciences ◽

10.3390/app11125415 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5415

Author(s):

Aleksandr Gorst ◽

Kseniya Zavyalova ◽

Aleksandr Mironchev ◽

Andrey Zapasnoy ◽

Andrey Klokov

Keyword(s):

Experimental Measurement ◽

Glucose Concentration ◽

Field Experiments ◽

Near Field ◽

Vector Network Analyzer ◽

Human Hand ◽

Physical Parameters ◽

Network Analyzer ◽

Frequency Range ◽

Average Deviation

The article investigates the near-field probe of a special design to account for changes in glucose concentration. The probe is designed in such a way that it emits radiation in both directions from its plane. In this paper, it was proposed to modernize this design and consider the unidirectional emission of the probe in order to maximize the signal and reduce energy loss. We have done extensive research for both bidirectional and unidirectional probe designs. Numerical simulations and field experiments were carried out to determine different concentrations of glucose (0, 4, 5.3, 7.5 mmol/L). Numerical modeling of a unidirectional probe showed that the interaction of radiation generated by such a probe with a multilayer structure simulating a human hand showed a better result and high sensitivity compared to a bidirectional probe. Further, based on the simulation results, a phantom (physical model) of a human hand was recreated from layers with dielectric properties as close as possible to the properties of materials during simulation. The probe was constructed from a copper tube and matched both the geometric and physical parameters of the model. The experimental measurement was carried out using a vector network analyzer in the frequency range 2–10 GHz. The experimental measurement was carried out using a vector network analyzer in the frequency range 2–10 GHz for the unidirectional and bidirectional probes. Further, the results of the experiment were compared with the results of numerical simulation. According to the results of multiple experiments, it was found that the average deviation between the concentrations was 2 dB for a unidirectional probe and 0.4 dB for a bidirectional probe. Thus, the sensitivity of the unidirectional probe was 1.5 dB/(mmol/L) for the bidirectional one 0.3 dB/(mmol/L). Thus, the improved design of the near-field probe can be used to record glucose concentrations.

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MIXED CHARACTERISTIC OF S-PARAMETERS OF DIFFERENTIAL STRUCTURES

ВЕСТНИК ВОРОНЕЖСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА ◽

10.36622/vstu.2021.17.1.011 ◽

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

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Combined vector network analyzer and impedance analyzer for broadband determination of complex permittivity spectrum of glass beads with talc

10.5194/egusphere-egu2020-21613 ◽

2020 ◽

Author(s):

Justyna Szerement ◽

Hironobu Saito ◽

Kahori Furuhata ◽

Shin Yagihara ◽

Agnieszka Szypłowska ◽

...

Keyword(s):

Electrical Conductivity ◽

Soil Moisture ◽

Dielectric Permittivity ◽

Glass Beads ◽

Vector Network Analyzer ◽

Complex Dielectric Permittivity ◽

Network Analyzer ◽

Frequency Range ◽

Impedance Analyzer ◽

Permittivity Spectrum

Soil complex dielectric permittivity is frequency dependent. At low frequencies soil dielectric spectrum exhibits relaxation effects mainly due to interfacial phenomena caused by water strongly bounded to solid phase particles surfaces, double-layer effects and Maxwell-Wagner effect. At frequencies of several GHz and above, the influence of dielectric dispersion of free water dipoles can be observed.&#160; Since dielectric soil moisture meters operate at frequencies from kHz up to several GHz, their output can be affected by these phenomena.Currently, there is a variety of commercial sensors that operate at various frequencies from kHz up to several GHz. Most popular are TDR sensors with frequency band up to 1-2&#160;GHz and capacitance/impedance sensors that operate at a single frequency usually from the range 1-150&#160;MHz. Therefore, the knowledge of the broadband complex dielectric permittivity spectrum can help to improve the existing and develop new methods and devices for soil moisture and salinity estimation. Also, accurate characterization of complex dielectric permittivity spectrum of porous materials in the broadband frequency range is required for modeling of dielectric properties of materials in terms of moisture, salinity, density, mineralogy etc.The aim of the study was to measure the complex dielectric permittivity of glass beads with 5% talc moistened with distilled water and saline water (electrical conductivity of 500, 1000, 1500 mS/m). The experiment was carried out using a seven-rod probe connected to an impedance analyzer (IA) and a vector network analyzer (VNA) using a multiplexer in the frequency range from 40Hz to 110MHz (IA) and 10MHz to 500MHz (VNA). The glass beads (90-106 &#181;m, Fuji Manufacturing Industries, Japan) with 5% talc (Sigma Aldrich) in 4 different moisture and 4 different salinity values were examined. The results obtained from the IA and the VNA were combined and modeled with complex conductivity and dielectric permittivity model. The influence of water content and electrical conductivity on broadband complex dielectric spectra and the fitted model parameters was examined.&#160;The work has been supported by the National Centre for Research and Development, Poland, BIOSTRATEG3/343547/8/NCBR/2017.

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Electromagnetic characteristics of materials based on ultrafine hexaferrite powders

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1198/1/012005 ◽

2021 ◽

Vol 1198 (1) ◽

pp. 012005

Author(s):

YuN Gladkov ◽

AS Kachalov ◽

EYu Korovyn ◽

AA Pavlova

Keyword(s):

Composite Materials ◽

Dielectric Permittivity ◽

Frequency Dependence ◽

Mechanical Treatment ◽

Wide Band ◽

Vector Network Analyzer ◽

Network Analyzer ◽

Frequency Range ◽

Nanosized Powders ◽

Electromagnetic Characteristics

Abstract The electromagnetic characteristics of composite materials based on nanosized powders of W-type hexaferrites are considered in the article. It is shown that not only the composition, but also the mechanical treatment affects the electromagnetic parameters. This article presents the frequency dependence of the complex magnetic and dielectric permittivity of a system of W-type hexafferites. The studies were carried out on a universal wide-band measuring complex based on the Agilent PNA-X N4257A Vector Network Analyzer. The results are presented in the frequency range from 2 to 14 GHz.

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A 10 kHz to 6 GHz Low-Cost Vector Network Analyzer

Advances in Radio Science ◽

10.5194/ars-19-17-2021 ◽

2021 ◽

Vol 19 ◽

pp. 17-22

Author(s):

Andreas Depold ◽

Stefan Erhardt ◽

Robert Weigel ◽

Fabian Lurz

Keyword(s):

Dynamic Range ◽

Low Cost ◽

Vector Network Analyzer ◽

Network Analyzer ◽

Frequency Range ◽

Network Analyzers ◽

Commercial Off The Shelf ◽

Large Frequency ◽

Cost Vector

Abstract. This publication introduces a low-cost vector network analyzer with very large frequency range made of commercial off-the-shelf components. It utilizes two identical receivers and two directional bridges to allow for two fully bidirectional measurement ports. The design surpasses the performance of competing low-cost network analyzers in regards of dynamic range, frequency span and calibration capability.

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New aspects of power grid facilities personnel workplaces electromagnetic environment

Russian Journal of Occupational Health and Industrial Ecology ◽

10.31089/1026-9428-2020-60-9-569-574 ◽

2020 ◽

Vol 60 (9) ◽

pp. 569-574

Author(s):

Nina B. Rubtsova ◽

Sergey Yu. Perov ◽

Olga V. Belaya ◽

Tatiana A. Konshina

Keyword(s):

Transmission Lines ◽

Power Transmission ◽

Power Grid ◽

Spectral Characteristics ◽

Ground Level ◽

Frequency Characteristics ◽

Frequency Range ◽

Electromagnetic Environment ◽

Limit Values ◽

Special Assessment

Introduction. Electromagnetic safety of power grid facilities staff requires the exclusion of electromagnetic fields (EMF) harmful effects. EMF is evaluated by 50 Hz electric and magnetic fields (EF and MF) values in the framework of working conditions special assessment, and very rarely the analysis of the electromagnetic environment (EME) is carried out in depth. The aim of the study - EME hygienic assessment of power grid EHV facilities personnel workplace with adequate 50 Hz EF and MF levels evaluation as well as the analysis of EF and MF in the frequency range from 5 Hz to 500 Hz amplitude-frequency characteristics. Materials and methods. 50 Hz EF and MF values assessment was carried out on open switchgears (S) of substations and within sanitary breaks of 500 and 750 kV overhead power transmission lines (OTL). Measurements along to OTL trasses was performed using matrix-based method. Measurements and analysis of EF and MF values in 5-500 Hz frequency range amplitude-frequency characteristics were performed in the territory of 500 and 750 kV S. Results. Power frequency 50 Hz measurements results at 500 and 750 kV S ground-level personnel workplaces showed the presence of an excess of permissible limit values by EF intensity and the absence of an excess by MF. The measured EF values within 500 and 750 kV OTL sanitary gaps require limiting the working time of linemen due to the excess of the hygienic norms for full work shift, while the MP levels were almost completely within the standard values for persons not occupationally connected with electrical installations maintenance. MF and EE frequency range from 50 Hz to 500 Hz spectral characteristics analysis showed that 3rd harmonic percentage does not exceed 2.5% for EF and 6% for MF of the main level, the level of the 5th harmonic does not exceed 1% for EF and 3.5% for MF, the level of the 7th harmonic does not exceed 0.2% for EF and 0.8% for MF. These data show despite its low levels the contribution of MF different harmonics in a possible adverse impact on humane than EF corresponding harmonics. Conclusions. There was the confirmation of the previously justified use of the "matrix" scheme for of EF and MF values measurement along OTL routes. The relevance of to EF and MF all frequency components expos ure assessing possible health risk in extremely high voltage S territories and under OTL, based on international recommendations due to the lack of sanitary regulations in the Russian Federation for >50 Hz-30 kHz EF and MF, is shown.

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