scholarly journals IRRADIATOR WITH MINIMAL LOSSES OF PARABOLIC ANTENNA FOR RADIO MONITORING SYSTEMS OF INFORMATION CHANNELS OF RADIO RELAY COMMUNICATION LINES

2021 ◽  
pp. 24-30
Author(s):  
N. M. Karaschuk ◽  
I. A. Tsikalov ◽  
V. O. Savenko
Keyword(s):  
Circular Waveguide ◽  
Input Resistance ◽  
Outer Radius ◽  
Practical Significance ◽  
Detection Range ◽  
Radio Monitoring ◽  
Parabolic Antenna ◽  
Relay Communication ◽  
Communication Lines ◽  
Conical Horn

Analysis of the experience of modern struggle shows that the success of combat missions to sone extent depends on the timely detection of information from communication channels, in particular, radio relay communication lines. Increasing the detection range of the radio monitoring station can be achieved by using a mirror parabolic antenna with a radiation in the form of a conical horn with low losses due to the use of a matching device. The constructive decisions of matching devices are analysed and it is determined that most of them are resonant. The substantiation and selection of the design of the dielectric transformer with the length ( – wavelength in a round waveguide, m) for coordination of the conical horn irradiator in the whole band of its operating frequencies for the wave type is carried out. To achieve the goal, the methods of antenna theories and electrodynamics were used, in particular the theory of long lines. A mathematical apparatus has been developed for calculating the parameters of a dielectric transformer (the length ). It is stated that its impedance must be equal to the modulus of load resistance. The calculation of the value of the active transformed resistance according to the formula (10) always gives a positive value of the input resistance, the value of which is greater the greater the reactive load reactance. The reliability of the obtained formulas is confirmed by the convergence of units and graphs of dependences of the changes of the outer radius of the coaxial power line (its impedance), as well as the thickness and place of inclusion on the matching dielectric transformer . The practical significance of the research results lies in the possibility of improving the matching of a horn antenna based on a circular waveguide in the range of its operating frequencies for a certain type of wave.

scholarly journals Adjustable circuits on semiconductor switching elements as a matching device in radar stations for outer space monitoring

2020 ◽  
Vol 30 (4) ◽  
pp. 79-86
Author(s):  
S. V. Kulikov ◽  
S. Yu. Ashchunin ◽  
V. O. Korolev ◽  
V. N. Aldokhina
Keyword(s):  
Antenna Arrays ◽  
Mutual Influence ◽  
Outer Space ◽  
Input Resistance ◽  
Load Resistance ◽  
Practical Significance ◽  
Phased Array Antenna ◽  
Complex Load ◽  
Detection Range

Formulation of the problem. When scanning in space by a phased array antenna (PAA), which consists of a large number of emitters, there is an interaction between them in the form of impedance. It affects the matching quality of the receiving-transmitting module of the PAA with the emitter and leads to significant losses of power and detection range of the radar station.Objective. Improving the quality of the PAA emitters matching when changing the position of the antenna directional pattern beam in space due to the use of adjustable super high frequency (SHF) matching circuits on the switching elements.Results. The article substantiates an increase in the functional capabilities of the development of adjustable matching circuits of super-high frequencies due to the use of switching elements in the device, which allow reducing the influence of factors caused by a change in the input impedance of the radiating element in phased antenna arrays. Based on the presented mathematical model, the change in the input resistance of the radiating elements is taken into account, which arises due to their mutual influence, and makes it possible to research the potential characteristics of controlled circuits when their structure and parameters change. The method of choosing the structure and parameters allows the device to be adjusted to the change in the input complex load resistance and ensure the minimum voltage standing-wave ratio.Practical significance. The proposed device allows for the calculation of implemented adjustable matching circuits, which, with existing materials and manufacturing technologies, provide a decrease in losses and an increase in range. An experimental model of microstrip design was developed based on the proposed device and a field experiment was carried out, which confirmed the correctness of the approach to the developed device.

scholarly journals A Generalized Approach for Computation of Near Field Radiation Pattern of an Antenna

2014 ◽  
Vol 2014 ◽  
pp. 1-18
Author(s):  
Preetham Shankpal ◽  
Varun Arur ◽  
Govind Kadambi ◽  
James Shuttleworth
Keyword(s):  
Radiation Pattern ◽  
Near Field ◽  
Circular Waveguide ◽  
Field Analysis ◽  
Far Field ◽  
Magnetic Dipoles ◽  
Underlying Principle ◽  
Field Radiation ◽  
Conical Horn

A generalized procedure in the form of an analytical formulation for the determination of radiation pattern of an antenna at any arbitrary distance which covers the near field as well as far field is presented in this paper. With the prior knowledge of either the current or field distribution on the radiating aperture, the proposed near field analysis is generic and can be applied for wide variety of antenna elements. The underlying principle of the generalized procedure is tantamount to considering the radiating aperture as an array of point electric and magnetic dipoles. The validity and novelty of the proposed new approach have been substantiated considering an open ended circular cylindrical waveguide and a conical horn as case studies and treating the far field as a special case of near field with pertinent distance criterion. The effect of change in the distance of observation ranging from reactive near field to far field on the radiation patterns of these antennas has also been discussed. The simulation studies reveal that the depicted normalized phase patterns of both the circular waveguide and conical horn follow the changes in the profile of the corresponding amplitude patterns.

scholarly journals Ways to identify bearings in two-position goniometric airborne radiomonitoring systems.

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
V.I. Merkulov ◽  
◽  
D.A. Milyakov ◽  
A.S. Plyashechik ◽  
V.S. Chernov ◽  
...  
Keyword(s):  
Radio Emission ◽  
Confidence Region ◽  
Angular Position ◽  
General Idea ◽  
Practical Significance ◽  
Correct Identification ◽  
Emission Sources ◽  
Identification Methods ◽  
Radio Monitoring ◽  
Observation Area

For aeronautical goniometric systems for radio monitoring of radio emission sources (RES), one of the primary tasks is the identification of bearings. It is especially difficult to solve the problem of identifying bearings if there are several RESs in the observation area in the case when they are located in the same plane with the direction finders. In this case, the problem of identifying bearings in goniometric two-position systems is solved in the process of performing a two-stage procedure. At the first stage, the primary identification of single measurements of bearings is carried out separately at each receiving position (RP) when receiving radio signals from the RES, and at the second stage, the secondary (inter-positional) identification of bearings arriving from both RPs is carried out. In the initial identification, strobe and strobeless identification algorithms are used. In the secondary identification for selection of true and false points of intersection of bearings on the plane, it is proposed to use the kinematic parameters of the relative RES. However, this type of selection does not provide interposition identification with an arbitrary nature of the movement of the RES relative to the RP, and also assumes a constant angular position of the RP base on the plane. More practical are ways of identifying bearings with RES, in which the procedure for constructing a confidence region (CR) in the form of a circle with a certain radius is used. However, a more correct form of CR is an elliptical CR, since the errors in determining the position of the RES are characterized by an error ellipse, a particular case of which is a circle. Therefore, methods for identifying coordinate information have been developed, in which elliptical CRs are used. In this case, not only the bearings of the RES, but also other measured parameters, for example, estimates of the rectangular coordinates of the RES, calculated on the basis of the triangulation method, can be used as coordinate information. The purpose of the article is to systematize and analyze the developed methods for identifying bearings, which allow one to get a fairly general idea of how to solve the problem of identifying bearings and indirect measurements of the coordinates of radio emission sources in aviation goniometric two-position radio monitoring systems. As a result, a classification of identification methods is given. The existing possibilities and limitations of using various identification methods in solving radio monitoring problems are analyzed. The necessary information on the methods and algorithms for interpositional identification of coordinate information about the position of the RES, using ellipsoidal CRs in solving the identification problem, is given. The practical significance of the presented methods is to increase the likelihood of correct identification of coordinate information, as well as the accuracy of the positioning of RES due to the use of elliptical CRs, which more accurately reflect the regularity of the distribution of errors in determining the position of RES.

scholarly journals DEVELOPMENT OF PROPOSALS FOR SELECTING AN ENSEMBLE OF BROADBAND SIGNALS SATELLITE COMMUNICATION SYSTEMS WITH MULTI-STATION ACCESS AND CODE DIVISION OF CHANNALS

T-Comm ◽  
2021 ◽  
Vol 15 (4) ◽  
pp. 13-20
Author(s):  
Vladimir I. Filatov ◽  
◽  
Vitaly A. Julego ◽  
Valery U. Balakirev ◽  
Sergey S. Ushakov ◽  
...  
Keyword(s):  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Satellite Communication ◽  
Spatial Location ◽  
Signal Propagation ◽  
Diagnostic Methods ◽  
Power Flux ◽  
Coverage Area ◽  
Radio Monitoring ◽  
Communication Lines

When designing satellite communication lines and calculating service areas, any unfavorable combinations of signal propagation conditions are taken into account, which, during operation of the repeater, leads to a significant underestimation of the calculated signal level in comparison with the actually provided one. Under these conditions, control of the compliance of the declared characteristics with the real level of the power flux density created by the satellite repeater at the earth’s surface in order to ensure electromagnetic compatibility is the most priority task. When conducting radio monitoring of satellite communication lines using active diagnostic methods, it is necessary to rationally determine the parameters of diagnostic signals so that they meet the conflicting requirements for their confident reception after being relayed by a satellite without disrupting (reducing the capacity) of the functioning of satellite communication lines. Mathematical modeling of the retransmission path of diagnostic signals in the multi-station repeater mode, taking into account the relative spatial location of the satellite, the service area and the radio monitoring station, has been carried out. The model takes into account most of the known factors and features of the propagation of radio signals in satellite communication lines in relation to various statistical phenomena in the atmosphere (refraction, signal depolarization), as well as the instability of the position of the satellite in orbit and the associated variability of the boundaries of the coverage area. As a result of the simulation, it was concluded that under conditions of a priori uncertainty about the polarization parameters used on board the monitored satellite of the antennas, there is a fundamental possibility of active diagnostics of the repeater shafts without weakening the diagnostic signal due to polarization mismatch.

scholarly journals Design & Analysis of S-Band Right Hand Circularly Polarized Conical Horn Antenna for NavIC Receiver

2018 ◽  
Vol 7 (3.12) ◽  
pp. 512 ◽  
Author(s):  
Likith N ◽  
Gayathri K M ◽  
Thusshara S ◽  
Maria Sanjeetha ◽  
Thangadurai N
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Circular Waveguide ◽  
Horn Antenna ◽  
High Gain ◽  
Band Frequency ◽  
Right Hand ◽  
The Right ◽  
Conical Horn ◽  
Very High

In satellite communication systems the horn antennas are being used widely due to its robustness and capable to operate at frequencies which are very high. Here, the right hand circular polarized conical horn antenna is designed for S-band NavIC receiver. The waveguides and conical horn antenna dimensions are designed by using standard formulas and after that they are given to a simulation tool for the S band frequency. The performance parameters like return loss, radiation pattern, gain and directivity are considered for further analysis. In the circular waveguide from the TE11 mode conical horn antenna is to be designed into high gain and a good VSWR.  

Trajectory control methods for observation in two-position angular airborne radio monitoring systems Part 1. Orthogonal methods

2021 ◽  
Author(s):  
V.I. Merkulov ◽  
D.A. Milyakov ◽  
V.P. Khar’kov ◽  
V.S. Chernov
Keyword(s):  
Experimental Studies ◽  
Trajectory Control ◽  
Practical Significance ◽  
Mutual Arrangement ◽  
Monitoring Systems ◽  
Control Methods ◽  
Practical Application ◽  
Radio Monitoring ◽  
First Case ◽  
Orthogonal Methods

Formulation of the problem. Currently, much attention is paid to the practical application and further improvement of two-position goniometric systems (TPGS) airborne radio monitoring, the advantage of which over single-position systems is the possibility of almost instantaneous determination of the location of the radio emission source (RES). A feature of the operation of the TPGS is the dependence of the errors in the positioning of the RES on the «geometry» of the system, i.e. on the size of the base and the position of the RES relative to the base. That is why the problem of optimizing the mutual arrangement of the receiving positions and RES is very urgent. To minimize positioning errors, two groups of trajectory observation control (TOC) methods have been developed, which is due to the variety of conditions for the practical use of aviation goniometric two-position systems and different degrees of their effectiveness. The first group of methods, called orthogonal, provides control of the receiving positions placed on the aircraft, so that the lines of sight of the RES relative to them intersect at right angles. The formation of a right-angled triangulation triangle, at the vertices of which the aircraft and RES are located, can be ensured by appropriate movement of the information support aircraft, or by simultaneously pointing both aircraft. In the first case, it is envisaged to output the information aircraft to an arbitrary point of a straight line, orthogonal to the line of sight «leading aircraft-RES», during the flight along which the best conditions for observation are created, or to a given point on this line. The second group of TOC methods ensures the minimization of errors in the positioning of radioactive sources at each current moment of time. When developing the corresponding trajectory control algorithms that implement the indicated trajectory control methods, direct and indirect optimization methods were used. To date, various TOC methods have been developed, but there is no systematic presentation of them. Purpose. To give a systematized idea of the developed methods of trajectory control of observation in two-position goniometric systems for radio monitoring of the surrounding space, as well as ways of solving the problem of ensuring the best observation conditions and increasing the accuracy of estimating the phase coordinates of the RES in these systems. Results. In the first part of this article, orthogonal methods and algorithms of TOC are considered, the implementation of which contributes to a significant increase in the accuracy of estimating the coordinates of the RES in goniometric two-position airborne radio monitoring systems. Information on the results of experimental studies confirming the effectiveness of the developed TOC methods is also given. Practical significance. The areas of practical application of various TOC methods in solving radio monitoring problems are shown, information about which can be used when choosing rational trajectory control methods for specific conditions of practical application, as well as when developing new TOC methods.

scholarly journals ACCOUNTING AND ANALYTICAL SUPPORT STRATEGY SUSTAINABLE DEVELOPMENT OF ENTERPRISE

2019 ◽  
pp. 130-143
Author(s):  
Nataliia PRAVDIUK
Keyword(s):  
Sustainable Development ◽  
Information Management ◽  
Development Strategy ◽  
Business Environment ◽  
The State ◽  
Practical Significance ◽  
Detection Range ◽  
The Sustainable Development ◽  
Methodological Guidelines ◽  
Ecological Capital

The purpose of the article - the detection range of issues of accounting and analytical support sustainable development and scientific substantiation of theoretical and methodological guidelines for their decision management in the agricultural business. Research methodology. The methodological basis of the study is the historical-logical method used in the study of the essence of the strategy of sustainable development. The dialectical method has been used in the study of the information management of the strategy of sustainable development of the enterprise. When analyzing the performance of the financial condition of agricultural enterprises for the 2013-2017 biennium. Methods used functional and statistical analysis. The method of comparison is used to study and compare the domestic and foreign experience of carrying out the accounting estimation of sustainable development. To clarify the content of accounting and analytical support sustainable development strategy used methods of abstraction, synthesis, induction and deduction, specification and other methods of scientific knowledge. The results of the research. Based on the substantiation of the importance of developing and implementing the strategy of sustainable development of the enterprise in the conditions of the modern business environment, the structure of the information management of the strategy of sustainable development management, which includes information resources generated by the external and internal environment of the enterprise, was investigated. It was established that the basis of internal information management of the strategy of sustainable development of the enterprise is the accounting and analytical system of the enterprise. To form a qualitative accounting and analytical support for management of the sustainable development strategy, a clarified understanding of the accounting and analytical support of the strategy of sustainable development, taking into account the specifics of the activities of agrarian enterprises, is substantiated, and the necessity of improving normative support in collecting information about the state of social and ecological capital according to typical reporting forms is substantiated. Elements of scientific novelty. A clarified understanding of the accounting and analytical support of the sustainable development strategy is proposed, taking into account the specifics of the activities of agrarian enterprises, the need to improve regulatory support in collecting information on the state of social and ecological capital by typical reporting forms. Practical significance. The proposals outlined in the article will help solve the problems of accounting and analytical support for the formation of a strategy for sustainable development of the industry and agribusiness. Tabl .: 6. Fig. 2. Bibliographer: 17.

Seti Figure of Merit

1997 ◽  
Vol 161 ◽  
pp. 711-717 ◽  
Author(s):  
John W. Dreher ◽  
D. Kent Cullers
Keyword(s):  
Figure Of Merit ◽  
Qualitative Difference ◽  
Current Generation ◽  
Detection Range ◽  
Sky Surveys ◽  
Independent Observations ◽  
Good For

AbstractWe develop a figure of merit for SETI observations which is anexplicitfunction of the EIRP of the transmitters, which allows us to treat sky surveys and targeted searches on the same footing. For each EIRP, we calculate the product of terms measuring the number of stars within detection range, the range of frequencies searched, and the number of independent observations for each star. For a given set of SETI observations, the result is a graph of merit versus transmitter EIRP. We apply this technique to several completed and ongoing SETI programs. The results provide a quantitative confirmation of the expected qualitative difference between sky surveys and targeted searches: the Project Phoenix targeted search is good for finding transmitters in the 109to 1014W range, while the sky surveys do their best at higher powers. Current generation optical SETI is not yet competitive with microwave SETI.

Specimen Preparation for Clinical Applications of X-Ray Microanalysis

1990 ◽  
Vol 48 (2) ◽  
pp. 328-329
Author(s):  
J.D. Shelburne ◽  
G.M. Roomans
Keyword(s):  
Carbon Coating ◽  
Clinical Applications ◽  
Point Of View ◽  
Practical Significance ◽  
Sweat Test ◽  
Specimen Preparation ◽  
Tissue Preparation ◽  
X Ray ◽  
Gallbladder Stones ◽  
Clinical Problems

Proper preparative procedures are a prerequisite for the validity of the results of x-ray microanalysis of biological tissue. Clinical applications of x-ray microanalysis are often concerned with diagnostic problems and the results may have profound practical significance for the patient. From this point of view it is especially important that specimen preparation for clinical applications is carried out correctly.Some clinical problems require very little tissue preparation. Hair, nails, and kidney and gallbladder stones may be examined and analyzed after carbon coating. High levels of zinc or copper in hair may be indicative of dermatological or systemic diseases. Nail clippings may be analyzed (as an alternative to the more conventional sweat test) to confirm a diagnosis of cystic fibrosis. X-ray microanalysis in combination with scanning electron microscopy has been shown to be the most reliable method for the identification of the components of kidney or gallbladder stones.A quantitatively very important clinical application of x-ray microanalysis is the identification and quantification of asbestos and other exogenous particles in lung.

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