Pub Date : 2024-02-07DOI: 10.3103/s0735272723010041
Yu. M. Poplavko, Yu. V. Didenko, D. D. Tatarchuk
Abstract
The paper analyzes the absorption efficiency of electromagnetic (EM) radiation by components of microwave shielding composites. EM wave in the absorbing material loses its energy during the interaction with molecular and electron structure of material. The mechanisms of wave absorption in dielectrics, semiconductors, magnetics and metals are considered with due regard for dimensional effects. It has been established that the absorption capacity of semiconductor and magnetic fillers of composites decreases to the extent of frequency rise. The recommendations for the selection of absorbing components of shielding composites intended for different frequency ranges are provided.
{"title":"Microwave Parameters of Components of Shielding Composites. Part 2: Mechanisms of Microwave Absorption","authors":"Yu. M. Poplavko, Yu. V. Didenko, D. D. Tatarchuk","doi":"10.3103/s0735272723010041","DOIUrl":"https://doi.org/10.3103/s0735272723010041","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper analyzes the absorption efficiency of electromagnetic (EM) radiation by components of microwave shielding composites. EM wave in the absorbing material loses its energy during the interaction with molecular and electron structure of material. The mechanisms of wave absorption in dielectrics, semiconductors, magnetics and metals are considered with due regard for dimensional effects. It has been established that the absorption capacity of semiconductor and magnetic fillers of composites decreases to the extent of frequency rise. The recommendations for the selection of absorbing components of shielding composites intended for different frequency ranges are provided.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-07DOI: 10.3103/s0735272722090035
F. F. Dubrovka, A. V. Bulashenko
Abstract
The paper proposes a developed approximate analytical method of constructive synthesis of compact polarizers based on two reactive elements in a square waveguide. The analytical synthesis was carried out under conditions of the absence of reflection and obtaining a required phase shift. As a result, simple formulas have been derived that determine parameters of phase-shifting elements and the electrical distance between them. The constructive synthesis was performed under conditions of the equality of required and real admittances of posts and diaphragms in a square waveguide and their derivatives at the central frequency of the working frequency band. As a result, the real geometrical dimensions of polarizers based on two posts and based on two diaphragms in a square waveguide were determined that provided for maximally flat phase-frequency characteristic. It has been shown that the polarizer based on two posts in a square waveguide can ensure the working frequency band of 4% or 13% while reflecting the electromagnetic energy of less than 1% or 10%, respectively, and differential phase shift Δφ = 90°±1°. However, polarizer based on two diaphragms in a square waveguide under the same conditions can ensure the working frequency band of up to 11% or 18%, respectively. The theoretical results were confirmed by experimental data.
{"title":"Analytical Method of Constructive Synthesis of Compact Polarizers with Maximally Flat Phase-Frequency Characteristic Based on Two Reactive Elements in Square Waveguide","authors":"F. F. Dubrovka, A. V. Bulashenko","doi":"10.3103/s0735272722090035","DOIUrl":"https://doi.org/10.3103/s0735272722090035","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper proposes a developed approximate analytical method of constructive synthesis of compact polarizers based on two reactive elements in a square waveguide. The analytical synthesis was carried out under conditions of the absence of reflection and obtaining a required phase shift. As a result, simple formulas have been derived that determine parameters of phase-shifting elements and the electrical distance between them. The constructive synthesis was performed under conditions of the equality of required and real admittances of posts and diaphragms in a square waveguide and their derivatives at the central frequency of the working frequency band. As a result, the real geometrical dimensions of polarizers based on two posts and based on two diaphragms in a square waveguide were determined that provided for maximally flat phase-frequency characteristic. It has been shown that the polarizer based on two posts in a square waveguide can ensure the working frequency band of 4% or 13% while reflecting the electromagnetic energy of less than 1% or 10%, respectively, and differential phase shift Δφ = 90°±1°. However, polarizer based on two diaphragms in a square waveguide under the same conditions can ensure the working frequency band of up to 11% or 18%, respectively. The theoretical results were confirmed by experimental data.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-07DOI: 10.3103/s0735272723010016
Dolley Shukla, Preeti Chandrakar
Abstract
As the health care system moves toward value-based care, Clinical Management System (CMS) has designed a number of programs to improve the quality of patient care. One of these programs is called the Hospital Patient Admission Cost Analysis Program, which helps the patient and the hospital to diagnose the disease and estimate the cost of hospitalization. According to the World Health Organization (WHO), the personal and medical costs have skyrocketed faster than the global economy. Major attributes which cause an increase in expenditure include smoking, ageing and increased Body Mass Index (BMI). In this study, we find a correlation between medical costs and various items using the insurance data of different people with characteristics such as smoking, age, the number of children, region and BMI. This study can also be used to demonstrate different models of regression that can be used to forecast insurance costs. Machine learning significantly reduces human efforts because machine learning models can compute cost calculations in short time, for which human beings take much more time.
{"title":"Predicting Patient Hospital Charges Using Machine Learning","authors":"Dolley Shukla, Preeti Chandrakar","doi":"10.3103/s0735272723010016","DOIUrl":"https://doi.org/10.3103/s0735272723010016","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>As the health care system moves toward value-based care, Clinical Management System (CMS) has designed a number of programs to improve the quality of patient care. One of these programs is called the Hospital Patient Admission Cost Analysis Program, which helps the patient and the hospital to diagnose the disease and estimate the cost of hospitalization. According to the World Health Organization (WHO), the personal and medical costs have skyrocketed faster than the global economy. Major attributes which cause an increase in expenditure include smoking, ageing and increased Body Mass Index (BMI). In this study, we find a correlation between medical costs and various items using the insurance data of different people with characteristics such as smoking, age, the number of children, region and BMI. This study can also be used to demonstrate different models of regression that can be used to forecast insurance costs. Machine learning significantly reduces human efforts because machine learning models can compute cost calculations in short time, for which human beings take much more time.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-07DOI: 10.3103/s0735272723030020
V. I. Slyusar
Abstract
In the article, the substantiated proposals for the use of YOLO family neural networks to detect the underwater undetonated munitions are proposed. At the same time, the YOLO3, YOLO4 and YOLO5 neural networks previously trained on the MS COCO dataset are used. The retraining of YOLO3 and YOLO4 neural networks is carried out on the modified Trash-ICRA19 underwater trash dataset, with the number of object classes equal to 13 and 2 of them are fictitious. The average class detection accuracy of 13 object classes using YOLO4 in the mAP50 metric is equal to 75.2 or 88.9% taking into account fictitious classes. The images obtained from video recordings of the demining reservoirs process with the help of remotely operated underwater vehicles (ROV) are used to test neural networks. The improved neural network as a cascade of several serially connected YOLO-segments with multi-pass image processing and tensor-matrix description of the attention mechanism are proposed. The recommendations for further increasing the efficiency of the neural network method of underwater munition selection are developed.
{"title":"Application of Neural Network Technologies for Underwater Munitions Detection","authors":"V. I. Slyusar","doi":"10.3103/s0735272723030020","DOIUrl":"https://doi.org/10.3103/s0735272723030020","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In the article, the substantiated proposals for the use of YOLO family neural networks to detect the underwater undetonated munitions are proposed. At the same time, the YOLO3, YOLO4 and YOLO5 neural networks previously trained on the MS COCO dataset are used. The retraining of YOLO3 and YOLO4 neural networks is carried out on the modified Trash-ICRA19 underwater trash dataset, with the number of object classes equal to 13 and 2 of them are fictitious. The average class detection accuracy of 13 object classes using YOLO4 in the mAP50 metric is equal to 75.2 or 88.9% taking into account fictitious classes. The images obtained from video recordings of the demining reservoirs process with the help of remotely operated underwater vehicles (ROV) are used to test neural networks. The improved neural network as a cascade of several serially connected YOLO-segments with multi-pass image processing and tensor-matrix description of the attention mechanism are proposed. The recommendations for further increasing the efficiency of the neural network method of underwater munition selection are developed.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-29DOI: 10.3103/s0735272722120032
Victor Kazmirenko, Yuriy Poplavko, Yuriy Yakymenko
Abstract
In some noncentrosymmetric crystals, their internal polarity can significantly influence the electric charge transfer. Sometimes, mixed ion-covalent bonds that are intrinsic to polar crystals are extremely delicately balanced, therefore, external stimuli (temperature or electric field) lead to a large change of the specific electrical resistance. In this case, even a small violation in the structure of materials stipulates a significant influence on electrical resistance, namely, a strong temperature dependence of the specific resistance of critistors and posistors and also field dependence of the specific resistance in varistors and controlled switching elements. A high sensitivity of specific resistance to peculiarities of the external environment that is stipulated by the imbalance of the internal polarity of active material is used in sensors. The analysis of the influence on electric charge transfer in polar structures can be crucial for the improvement of appropriate materials.
{"title":"Charge Transfer in Polar Crystals","authors":"Victor Kazmirenko, Yuriy Poplavko, Yuriy Yakymenko","doi":"10.3103/s0735272722120032","DOIUrl":"https://doi.org/10.3103/s0735272722120032","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In some noncentrosymmetric crystals, their internal polarity can significantly influence the electric charge transfer. Sometimes, mixed ion-covalent bonds that are intrinsic to polar crystals are extremely delicately balanced, therefore, external stimuli (temperature or electric field) lead to a large change of the specific electrical resistance. In this case, even a small violation in the structure of materials stipulates a significant influence on electrical resistance, namely, a strong temperature dependence of the specific resistance of critistors and posistors and also field dependence of the specific resistance in varistors and controlled switching elements. A high sensitivity of specific resistance to peculiarities of the external environment that is stipulated by the imbalance of the internal polarity of active material is used in sensors. The analysis of the influence on electric charge transfer in polar structures can be crucial for the improvement of appropriate materials.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138543037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-29DOI: 10.3103/s0735272722120020
Yuriy Poplavko, Yurii Didenko, Dmytro Tatarchuk
Abstract
Polymer, rubber and other dielectric composites filled with powder additives that absorb microwaves are widely applied in radio-electronics for reducing the reflection from metallic surfaces and suppression of electromagnetic noise. The efficiency analysis of absorbing microwave composites involves the need to determine the fundamental reasons that describe the reflection and absorption of electromagnetic (EM) radiation in materials, which are the components of shielding composite. This study consists of two parts. The first considers mechanisms of EM wave reflection from dielectrics, semiconductors, magnetics, and metals. The second part is devoted to EM wave absorption in these materials with due regard for dimensional effects. The impact of different components on microwave parameters of composites has been also analyzed.
{"title":"Microwave Parameters of Components of Shielding Composites. Part 1: Mechanisms of Microwave Reflection","authors":"Yuriy Poplavko, Yurii Didenko, Dmytro Tatarchuk","doi":"10.3103/s0735272722120020","DOIUrl":"https://doi.org/10.3103/s0735272722120020","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Polymer, rubber and other dielectric composites filled with powder additives that absorb microwaves are widely applied in radio-electronics for reducing the reflection from metallic surfaces and suppression of electromagnetic noise. The efficiency analysis of absorbing microwave composites involves the need to determine the fundamental reasons that describe the reflection and absorption of electromagnetic (EM) radiation in materials, which are the components of shielding composite. This study consists of two parts. The first considers mechanisms of EM wave reflection from dielectrics, semiconductors, magnetics, and metals. The second part is devoted to EM wave absorption in these materials with due regard for dimensional effects. The impact of different components on microwave parameters of composites has been also analyzed.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"20 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138527222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-29DOI: 10.3103/s0735272722120044
Yurii Yakymenko, Oleksandr Machulianskyi, Bohdan Babych, Viktor Hetmanchuk
Abstract
In this paper there are represented spectral-selective elements with definite optical characteristics on a basis of metal-dielectric composite structures. There is shown the possibility of controlling of the spectral selectivity of such structures due to modification of structural parameters of nanodimension components and accounting of their electromagnetic properties. The results of electronic microscopic and spectral photometric researches for experimental samples of nanodimensional silver films are discussed. Experimental values of electromagnetic parameters of nanodimensional metal layers are determined. There are specified the characteristics of their spectral dependences. It is carried out comparative analysis of complex permittivity of nanodimensional silver films with correspondent dependences which are specific for a metal microscopic volume. Here it is considered a model of nanostructure composite system response on electromagnetic impact. The mathematic model is based on approximation of effective media and application of phenomenological theory of electromagnetic properties of layer film structure. The value of effective complex permittivity of nanostructure composites with dielectric component on a basis of silicon dioxide and nanodimensional chrome inclusions is defined taking into account experimental values of electromagnetic parameters of nanodimensional components. There are defined the approximation spectral dependences of electromagnetic parameters of complex dielectric permittivity for the composites Cr/SiO2 which are used for simulation and research of nanocomposite layers influence on spectral characteristics of optical selective components.
{"title":"Metal-Dielectric Nanocomposite Structures with Definite Optical Selective Properties","authors":"Yurii Yakymenko, Oleksandr Machulianskyi, Bohdan Babych, Viktor Hetmanchuk","doi":"10.3103/s0735272722120044","DOIUrl":"https://doi.org/10.3103/s0735272722120044","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In this paper there are represented spectral-selective elements with definite optical characteristics on a basis of metal-dielectric composite structures. There is shown the possibility of controlling of the spectral selectivity of such structures due to modification of structural parameters of nanodimension components and accounting of their electromagnetic properties. The results of electronic microscopic and spectral photometric researches for experimental samples of nanodimensional silver films are discussed. Experimental values of electromagnetic parameters of nanodimensional metal layers are determined. There are specified the characteristics of their spectral dependences. It is carried out comparative analysis of complex permittivity of nanodimensional silver films with correspondent dependences which are specific for a metal microscopic volume. Here it is considered a model of nanostructure composite system response on electromagnetic impact. The mathematic model is based on approximation of effective media and application of phenomenological theory of electromagnetic properties of layer film structure. The value of effective complex permittivity of nanostructure composites with dielectric component on a basis of silicon dioxide and nanodimensional chrome inclusions is defined taking into account experimental values of electromagnetic parameters of nanodimensional components. There are defined the approximation spectral dependences of electromagnetic parameters of complex dielectric permittivity for the composites Cr/SiO<sub>2</sub> which are used for simulation and research of nanocomposite layers influence on spectral characteristics of optical selective components.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"28 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138527224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper describes methods for obtaining nanocellulose from miscanthus stalks in an environmentally friendly way using the hydrolysis method. The nanocellulose parameters were investigated for applying the nanocellulose in capacitive and resistive humidity sensors. The influence of electrode system parameters and the operating frequency on sensor characteristics was investigated. It was established that the device sensitivity increases with the reduction of distance between electrodes and the operating frequency. Two models of sorption processes at the gas–solid interface were applied, namely, the Freundlich isotherm and Langmuir isotherm, for describing the mechanism of water adsorption by nanocellulose-based humidity sensors. The long-term operation stability of such devices was also investigated.
{"title":"Capacitive and Resistive Humidity Sensors Based on Flexible Nanocellulose Film for Wearable Electronics","authors":"Vladyslav Lapshuda, Viktoriia Koval, Mykhailo Dusheiko, Valerii Barbash, Olga Yashchenko, Serhii Maliuta","doi":"10.3103/s0735272722120019","DOIUrl":"https://doi.org/10.3103/s0735272722120019","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper describes methods for obtaining nanocellulose from miscanthus stalks in an environmentally friendly way using the hydrolysis method. The nanocellulose parameters were investigated for applying the nanocellulose in capacitive and resistive humidity sensors. The influence of electrode system parameters and the operating frequency on sensor characteristics was investigated. It was established that the device sensitivity increases with the reduction of distance between electrodes and the operating frequency. Two models of sorption processes at the gas–solid interface were applied, namely, the Freundlich isotherm and Langmuir isotherm, for describing the mechanism of water adsorption by nanocellulose-based humidity sensors. The long-term operation stability of such devices was also investigated.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138527288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-29DOI: 10.3103/s0735272722120056
Yevgenii Rogozhkin, Leonid Emelyanov, Valeriy Pulyayev, Igor Domnin, Artem Miroshnikov, Nataliia Kuzmenko
Abstract
The paper considers the variants of improving the operation modes of high-power ground-based means of near-Earth space remote sensing, i.e., radars that employ the method of incoherent scattering (IS) of radiowaves in ionospheric plasma. Examples of experimental results of obtaining values of the electron concentration in ionosphere using the measurement of height power distribution of IS signal and its processing are presented. The functional block-diagrams of IS radar for different operation modes, in particular using the orthogonal excitation antenna dipoles and ring bridge, were also presented. Peculiarities of radiation and reception of radiowaves with both linear and circular polarization are considered. In the first case, the effect of Faraday rotation of radiowave polarization plane is used that causes typical IS signal fading when this signal is received by the linearly polarized antenna and consequently fluctuations in the height power profile of IS signal and also in the function obtained by processing the orthogonal components of signal that is used for the calculation of electron concentration. In the second case, the values of electron concentration are obtained by using the profile of IS signal power, in which the impact of the Faraday effect is eliminated. The results of conducted experiments simultaneously for the upper and lower ionosphere are presented including the calculation of concentration of ionospheric plasma electrons with sufficient height resolution dependent on the duration of elements of composed probing signal. The radiation mode of two-element radio-pulse with the direction change of polarized wave rotation has been proposed for simultaneous measuring of ionosphere parameters in a wide range of heights.
{"title":"Hardware and Algorithmic Features of Radiation, Reception and Processing of Signals Using Incoherent Scatter Technique","authors":"Yevgenii Rogozhkin, Leonid Emelyanov, Valeriy Pulyayev, Igor Domnin, Artem Miroshnikov, Nataliia Kuzmenko","doi":"10.3103/s0735272722120056","DOIUrl":"https://doi.org/10.3103/s0735272722120056","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper considers the variants of improving the operation modes of high-power ground-based means of near-Earth space remote sensing, i.e., radars that employ the method of incoherent scattering (IS) of radiowaves in ionospheric plasma. Examples of experimental results of obtaining values of the electron concentration in ionosphere using the measurement of height power distribution of IS signal and its processing are presented. The functional block-diagrams of IS radar for different operation modes, in particular using the orthogonal excitation antenna dipoles and ring bridge, were also presented. Peculiarities of radiation and reception of radiowaves with both linear and circular polarization are considered. In the first case, the effect of Faraday rotation of radiowave polarization plane is used that causes typical IS signal fading when this signal is received by the linearly polarized antenna and consequently fluctuations in the height power profile of IS signal and also in the function obtained by processing the orthogonal components of signal that is used for the calculation of electron concentration. In the second case, the values of electron concentration are obtained by using the profile of IS signal power, in which the impact of the Faraday effect is eliminated. The results of conducted experiments simultaneously for the upper and lower ionosphere are presented including the calculation of concentration of ionospheric plasma electrons with sufficient height resolution dependent on the duration of elements of composed probing signal. The radiation mode of two-element radio-pulse with the direction change of polarized wave rotation has been proposed for simultaneous measuring of ionosphere parameters in a wide range of heights.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"19 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138527221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-06DOI: 10.3103/s0735272722120081
Pavlo Yu. Kostenko, Valeriy V. Slobodyanuk, H. Yu. Dukin
Abstract
The paper considers a potential resolution of BDS criterion that is used as a goal function in solving the problem of Doppler frequency estimation and the delay of a wideband phase-shift keying pulse signal. For the purpose of investigating the BDS criterion characteristics, BDS-criterion is compared with the maximum likelihood (ML) criterion. A comparative analysis is conducted using the sensitivity function (SF) of BDS criterion and the wideband ambiguity function (WAF) of BPSK signals that make it possible to determine the potential resolution of the methods under consideration. The results of numerical simulation of SF characteristics for BPSK signal were conducted for the cases of presence and absence of noise in observation. The resolution of above criteria was analyzed both with due regard for the signal carrier frequency and in terms of its complex envelope. It was shown that in solving the problem of Doppler frequency estimation and the delay of BPSK signal, the resolution of BDS criterion can be enhanced by taking into account the carrier frequency. The comparative analysis of the resolution of selected criteria depending on the level of additive Gaussian noise in observation was also conducted. It was shown that at low noise levels the potential resolution of BDS criterion is higher than that of ML criterion.
{"title":"Comparative Analysis of Resolution of Nonparametric BDS Criterion and Maximum Likelihood Criterion for Estimation of Delay and Doppler Frequency Shift of Pulse Signal","authors":"Pavlo Yu. Kostenko, Valeriy V. Slobodyanuk, H. Yu. Dukin","doi":"10.3103/s0735272722120081","DOIUrl":"https://doi.org/10.3103/s0735272722120081","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper considers a potential resolution of BDS criterion that is used as a goal function in solving the problem of Doppler frequency estimation and the delay of a wideband phase-shift keying pulse signal. For the purpose of investigating the BDS criterion characteristics, BDS-criterion is compared with the maximum likelihood (ML) criterion. A comparative analysis is conducted using the sensitivity function (SF) of BDS criterion and the wideband ambiguity function (WAF) of BPSK signals that make it possible to determine the potential resolution of the methods under consideration. The results of numerical simulation of SF characteristics for BPSK signal were conducted for the cases of presence and absence of noise in observation. The resolution of above criteria was analyzed both with due regard for the signal carrier frequency and in terms of its complex envelope. It was shown that in solving the problem of Doppler frequency estimation and the delay of BPSK signal, the resolution of BDS criterion can be enhanced by taking into account the carrier frequency. The comparative analysis of the resolution of selected criteria depending on the level of additive Gaussian noise in observation was also conducted. It was shown that at low noise levels the potential resolution of BDS criterion is higher than that of ML criterion.</p>","PeriodicalId":52470,"journal":{"name":"Radioelectronics and Communications Systems","volume":"23 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138527239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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