E. Shafiee-Nejhad; N. Rahbar; M. Asghari; A. R. Novinzade
Volume 2, Issue 1 , April 2009, , Pages 59-65
Abstract
In this article the simulation of explosion and diffusion of debris consequent on explosion, in the space are studied. This method is simulated by the introduced code and the results are closely checked in accordance with different operational situations for the huge amounts of particles in different ...
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In this article the simulation of explosion and diffusion of debris consequent on explosion, in the space are studied. This method is simulated by the introduced code and the results are closely checked in accordance with different operational situations for the huge amounts of particles in different kinds of strategic orbits. Finally, the density distribution of debris that located in the same orbit is studied. The simulation examines the status of diffusion, trace settlement and also their location in orbits around the earth, during times that is wanted by user. Whatever satellite designing is immaculate, the satellite subsystems (such as batteries, propeller parts and etc) explosion and failing is possible, also smashing with the space masses is foreseeable. Regarding to the space orbits high expense and dedicating these orbits to each country; it is important to clean them from debris and necessary to understand this problem.
E. Amani; M. Ebrahimi; J. Roshanian
Volume 3, Issue 2 , January 2011, , Pages 59-67
Abstract
در این مقاله، معادلات کوپل‌شده جسم صلب- تلاطم سیال- الاستیسیته برای پرواز شش درجه آزادی ماهواره‌برها توسعه داده شده است. معادلات حرکت به کمک معادلات لاگرانژ در دستگاه ...
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در این مقاله، معادلات کوپل‌شده جسم صلب- تلاطم سیال- الاستیسیته برای پرواز شش درجه آزادی ماهواره‌برها توسعه داده شده است. معادلات حرکت به کمک معادلات لاگرانژ در دستگاه شبه مختصات و همچنین در دستگاه مختصات اینرسی استخراج شده‌اند. مدل پاندول ساده برای حرکت صفحه‌ای به منظور مدل کردن دینامیک تلاطم سیال در پرواز شش درجه آزادی گسترش داده شده و تغییر شکل‌های الاستیک بر اساس مختصات مودال نسبت به مختصات میانی ارائه شدند و نیز نشان داده شده است که این مدل با مدل ساده‌تر حرکت صفحه‌ای که در مطالعات پیشین توسعه یافته است، سازگاری دارد. مدل دینامیکی پیشنهاد شده در کنار مدل‌های لازم برای سایر زیرسیستم‌ها در برنامة متلب/ سیمولینک با موفقیت برای شبیه‌سازی حرکت شش درجه آزادی ماهواره‌برها به کار گرفته شده است.
Fateme Sadeghikia; Farokh HojatKashani; Jalil RashedMohasal; S. Javad Giyome- Bozorgi
Volume 5, Issue 3 , October 2012, , Pages 59-66
Abstract
Numerical investigation has been made on a linear array of surface wave driven plasma monopole antenna using finite difference time domain simulation. Variations of the excitation power can be used for construction of a dynamically reconfigurable antenna. Plasma elements in the nominal pressure of 0.4 ...
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Numerical investigation has been made on a linear array of surface wave driven plasma monopole antenna using finite difference time domain simulation. Variations of the excitation power can be used for construction of a dynamically reconfigurable antenna. Plasma elements in the nominal pressure of 0.4 mb are fed through an RF power at 500 MHz using an equal power divider. The results show that while the variations of the excitation power shift the array resonant frequency between 50 MHz to 120 MHz, the array gain and directivity remain approximately unchanged in the new resonant frequency. Since efficiency is critical to communication systems, the total efficiencies of the reconfigurable array were analyzed from the least to the highest excitation power. The highest efficiency belongs to the array which the separation between elements is a quarter of wavelength. Using this cutting edge technology in space application, it will be possible to transmit through an antenna in a multiple frequency avoiding interference between adjacent antennas.
investigating space radiation
Roghieh Karimzadeh Baee; Hamideh Daneshvar; Amir Hossin Ahmadi; Parvin Sojoodi
Volume 16, Issue 1 , March 2023, , Pages 59-74
Abstract
With the advent of GaN technology, achieving microwave power with high efficiency by solid-state devices has become more available. Therefore, the use of SSPA amplifiers with GaN technology in satellites, especially LEO satellites, has been considered. space radiation can affect the performance and reliability ...
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With the advent of GaN technology, achieving microwave power with high efficiency by solid-state devices has become more available. Therefore, the use of SSPA amplifiers with GaN technology in satellites, especially LEO satellites, has been considered. space radiation can affect the performance and reliability of components in space systems, which needs to be investigated. One of the most important technologies that can be affected by radiation effects is GaN transistors. In this paper, the effect of TID on GaN transistors in the SSPA amplifier board is investigated. Since commercial components have been used in the engineering sample of the SSPA amplifier and the calculations obtained from the RDM estimates under the worst conditions show that it is necessary to conduct a test for these components, the radiation resistance test was performed for this amplifier. The results of the test conducted in this article show that the SSPA GaN board has radiation tolerance up to a dose of approximately 16 krad. Therefore, mismatched GaN transistors are resistant up to this amount of dose. This is while the sequencer board actually has less tolerance than 5.5 krad
Alireza Aghalari; Javad Tayebi; Ahmad Kalhor
Volume 5, Issue 4 , January 2013, , Pages 61-68
Abstract
Recently, many space missions have been using small satellites, because small satellites are easier and faster to develop and thereby, provide increased launch opportunities. Some of these missions include tasks that required agile maneuvers. In this paper, attitude stability testing of an agile three-degree-freedom ...
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Recently, many space missions have been using small satellites, because small satellites are easier and faster to develop and thereby, provide increased launch opportunities. Some of these missions include tasks that required agile maneuvers. In this paper, attitude stability testing of an agile three-degree-freedom micro-satellite simulator – which is equipped with a pyramid arrangement of single-gimbal control-moment gyros (SGCMGs) – is presented. In the attitude stability testing, the local quadratic regulator (LQR) control strategy is used, which has superiority to other approaches due to its independence of using steering law. This simulator allow to test different control laws by using SGCMGs. In this work, after introducing the actuator and satellite simulator and using the control strategy in the simulator, the attitude stability testing is performed and then, the experimental results are presented and discussed. The results show the attitude stability of the simulator which is exposed to the disturbing toques.
M. Sh. Hosseinipanah; F. Abdoullah-Mianji
Volume 6, Issue 3 , October 2013, , Pages 61-66
Abstract
To improve the performance of satellite antennas, use of a high-impedance surface is purposed. High impedance surfaces are known as artificial magnetic conductors. The designed magnetic conductor includes an array of a Jerusalem Cross frequency selective surface which is connected to the ground via four ...
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To improve the performance of satellite antennas, use of a high-impedance surface is purposed. High impedance surfaces are known as artificial magnetic conductors. The designed magnetic conductor includes an array of a Jerusalem Cross frequency selective surface which is connected to the ground via four pins. All conducting parts are made of Aluminum.The dielectric is Arlon AD 270 that fills the space between the ground and the JC frequency selective surface. The dielectric is made of fiberglass reinforced by Poly-tetrafluorethylene (PTFE). In 4.73GHz and 7.43GHz, structure operatesas a magnetic conductor.Using computer simulations, this structure is compared with a widely used artificial magnetic conductor. Aluminum and polymer chain of Carbon and Fluorine are composed of light elements, therefore using this material in antenna structure not only can improve specification of antenna but also can reduce cosmic ray effects.
Reza Mohsenipour; Mehrzad Nasirian; Abdol Reza Kashaninia; Mohsen Fathi
Volume 8, Issue 1 , April 2015, , Pages 61-71
Abstract
Increasing in dimensions of the satellites and using light movingstructures, causes flexibility and uncertainty in their models. Therefor to control the attitude of the satellites, should use those methods which resist against the plant’s model uncertainty and could reject the disturbance and the ...
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Increasing in dimensions of the satellites and using light movingstructures, causes flexibility and uncertainty in their models. Therefor to control the attitude of the satellites, should use those methods which resist against the plant’s model uncertainty and could reject the disturbance and the measurementnoise. One of these methods is the robust control. But due to the location of the poles in the dynamic equations of the satellite, the design of robust controllers faces some problems. In this paper, using aninternal feedback, the dynamic equations are changed so that the poles are located in a more proper place. And then,considering flexibility affects as uncertainty and also, uncertainty in inertia matrix of the satellite, a H∞ controller, and finally to improve the performance, a µ-controller will be designed for the new equations. But these two controllers will be analyzed and compared for the primary equations and not for the new equations.For comparison, a classical controller is also designed forthe primary system.
Space systems design (spacecraft, satellites, space stations and their equipment)
Mona Habibi; Mahdi Fakoor; Hadi Parviz Nowruzani
Volume 14, Issue 1 , March 2021, , Pages 65-75
Abstract
In this research, to investigate the effects of uncertainties on the natural frequency of satellite system attributed to the variation of layout components, the optimal layout of the satellite is performed utilizing particle swarm optimization (PSO) algorithm, considering stability and geometrical constraints. ...
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In this research, to investigate the effects of uncertainties on the natural frequency of satellite system attributed to the variation of layout components, the optimal layout of the satellite is performed utilizing particle swarm optimization (PSO) algorithm, considering stability and geometrical constraints. In order to produce random samples, enough number of results will be extracted, which are mass center of components, and based on the outputs, the finite element modeling of different samples by considering mass point is carried out. After modal analysis, mass and stiffness matrices are extracted, the simulation of Monte - Carlo runs based on Wishart random matrix theory and the eigenvalues of the matrix, i.e. natural frequencies, are obtained. Probabilistic distribution of natural frequencies is shown that in the proposed layout, the distribution of samples is very low and the variation of natural frequency is robust to the proposed optimal location.
M. Taherbaneh; A.R. Fasooniehch; Sh. Karbasian; R. Amjadifard
Volume 1, Issue 1 , September 2008, , Pages 67-80
Abstract
In this paper, the effects of orbital–environmental parameters on the maximum delivered power of silicon solar cells in various orbits are investigated. The survey consists of the effects of radiation, irradiance, and temperature on solar cell electrical characteristics in LEO and GEO orbits. Applying ...
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In this paper, the effects of orbital–environmental parameters on the maximum delivered power of silicon solar cells in various orbits are investigated. The survey consists of the effects of radiation, irradiance, and temperature on solar cell electrical characteristics in LEO and GEO orbits. Applying radiation effect to “One-Diode” model of the solar cell and implementation of the model in MATLAB environment has been done. Then the verification of the model by the existing data, and simulation of radiation effects at AM0, in LEO and GEO orbits is implemented. Comparison of electrical characteristics of the cell at BOL and EOL in various orbits is a part of the results of the survey.
M. Navabi; M. Sabatifar
Volume 3, Issue 1 , July 2010, , Pages 67-74
Abstract
Orbital transfer has a significant role in any space mission. This transfers generally categorized in impulsive and continuous maneuvers. An important challenge is fuel consumption in the maneuver. This problem is considered as a required Δυ problem. Hence, minimization of Δυ ...
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Orbital transfer has a significant role in any space mission. This transfers generally categorized in impulsive and continuous maneuvers. An important challenge is fuel consumption in the maneuver. This problem is considered as a required Δυ problem. Hence, minimization of Δυ means minimization of fuel consumption orbital transfer. In simple cases, the problem has closed form solution for example transfer between coplanar circular orbits or transfer between coplanar coaxial elliptical orbits. The conventional methods cannot solve complex cases of initial and target orbits. In this paper the impulsive optimal transfer between two coplanar- noncoaxial elliptical orbits is considered. The numerical solution of optimality nonlinear equations is necessary to obtain the solutions of complex problems. According to nonlinearity of equations two issues arise, firstly numerical solution is sensitive to initial guess, secondly the local minimum solutions only may be find. In this paper some equations have been derived that using them behavior of required Δυ function can be investigate based on various values of independent variables and can be find the boundary of global solution. In this way one can be determined a reasonable and proper initial guess for nonlinear solver. The proposed methodology is applied to an example and the results are provided. The results include the local and global solutions and they show a good ability of the proposed method.
Seyed Hossein Torabi; Jafar Roshanian; Hamid Arabshahi
Volume 8, Issue 2 , July 2015, , Pages 67-78
Abstract
In this Paper, The online optimal integrated guidance and control algorithm design has been provided for two-stages Launch Vehicle .The flight equations are nonlinear and has been derived in flight plane. In order to solve it based on numerical solution and shooting method logic by the combination between ...
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In this Paper, The online optimal integrated guidance and control algorithm design has been provided for two-stages Launch Vehicle .The flight equations are nonlinear and has been derived in flight plane. In order to solve it based on numerical solution and shooting method logic by the combination between ODE - start to end solver algorithm by considering initial conditions for integrated states and co-states - and optimization fmincon SQP algorithm has been acted. In order to verify designing method the results of this algorithm solutions has been compared with the results of a valid separated guidance and control algorithm for launch vehicle. The result function involves minimum control effort, terminal terms and minimizing burning time. The results indicate the satisfaction of three mentioned identities achieving high accurate orbital insertion and more coordination between the operation of guidance and control algorithms in integrated logic comparing with separated ones.
commerce, management, and apace law
Mahdi Gholami
Volume 14, Issue 4 , December 2021, , Pages 67-76
Abstract
This paper examines the funding sources of space industry. First, an overview of the space economy and investment flows in the industry is presented. Long-run trends indicate an increase in public and private investment in the space industry. Government funding is the most important source of funding ...
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This paper examines the funding sources of space industry. First, an overview of the space economy and investment flows in the industry is presented. Long-run trends indicate an increase in public and private investment in the space industry. Government funding is the most important source of funding for space programs. Also, the international cooperations in this industry has played a significant role in the development path of space activities. On the other hand, more applications in the services and other economic sectors has increased the entry incentives for private investors. Therefore, financing space projects through private funds is also one of the growing trends in the space industry. The findings show that the shift of governments from construction investments to commercialization investments. In contrast, the increasing application of space activities and the digitalization pattern of the industry have paved the way for micro-actors to enter with less financial resources.
M. Karbasian; A. Bagheri
Volume 2, Issue 2 , July 2009, , Pages 69-73
Abstract
Recognition of any type of failures in systems and prediction of its reliability have important role in improvement of design of systems. Fault Tree Analysis (FTA) is one of the best techniques in analysis and improvement of complex systems. In this paper first, we show reliability block diagram (RBD) ...
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Recognition of any type of failures in systems and prediction of its reliability have important role in improvement of design of systems. Fault Tree Analysis (FTA) is one of the best techniques in analysis and improvement of complex systems. In this paper first, we show reliability block diagram (RBD) of Rocket Engine and then its fault tree is analyzed. Finally based on FTA, reliability of combustion of rocket engine is calculated.
A. Mohammadi; E. Taheri; J. Roshanian; M. Bahrami
Volume 4, Issue 1 , July 2011, , Pages 69-78
Abstract
In this research a perturbation based guidance method is developed for non-Keplerian problem. Problem is linearized in the presence non-gravitational forces like aerodynamic, so it can improve the performance of C* guidance for reentry problems. In this study developed method is used for a reentry guidance ...
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In this research a perturbation based guidance method is developed for non-Keplerian problem. Problem is linearized in the presence non-gravitational forces like aerodynamic, so it can improve the performance of C* guidance for reentry problems. In this study developed method is used for a reentry guidance accuracy and performance. Results showed significant increases in accuracy compared to Keplerian approaches.
E. Rezaeian Parsa; S. M. Mirsajedi
Volume 5, Issue 2 , July 2012, , Pages 69-74
Abstract
In this study, solid rocket motor internal ballistic, has been investigated. Flow field consists of internal grain space and converging-diverging nozzle. Axisymmetric, compressible and transient Euler equations have been considered as governing equations and erosive burning has been considered as an ...
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In this study, solid rocket motor internal ballistic, has been investigated. Flow field consists of internal grain space and converging-diverging nozzle. Axisymmetric, compressible and transient Euler equations have been considered as governing equations and erosive burning has been considered as an important phenomenon in solid rocket motors. Fluent software and its moving mesh capability have been used to flow field modeling. At the first time, an appropriate UDF has been utilized to achieve a good simulation of erosive burning. The results show very good agreement with other numerical results.
A. Imani; M. Bahrami
Volume 6, Issue 1 , April 2013, , Pages 69-75
Abstract
In this paper, in order to control the relative motion for spacecraft formation flying, an optimal sliding mode controller is presented. This controller is designed based on the linearized equations of relative motion in circular orbit and applied to nonlinear system that is subjected to external disturbance. ...
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In this paper, in order to control the relative motion for spacecraft formation flying, an optimal sliding mode controller is presented. This controller is designed based on the linearized equations of relative motion in circular orbit and applied to nonlinear system that is subjected to external disturbance. Firstly optimal controller is designed based on linear quadratic (LQ) method, and then integral sliding mode control technique is used to robustify the controller. It is assumed that spacecrafts move in low-earth orbits and J2 perturbation is considered as external disturbance. Using Lyapunov second method, the stability of the closed-loop system is guaranteed. The performance of the proposed controller in tracking the desired trajectory is compared to sliding mode controller and simulation results show the effective performance of the proposed controller.
R. Sayahnia; M. F. Makhdoum; S. Faryadi
Volume 7, Issue 3 , October 2014, , Pages 69-73
Abstract
Land is a limited and vulnerable resource with many permanent and renewable benefits if it is used appropriately.By considering the limited lands and the need for updated data and information for land planning, necessity and importance of land use studies is clear. In fact remote sensing data with geographic ...
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Land is a limited and vulnerable resource with many permanent and renewable benefits if it is used appropriately.By considering the limited lands and the need for updated data and information for land planning, necessity and importance of land use studies is clear. In fact remote sensing data with geographic information systems are strong tools in change detection of land use pattern. They are much cost and time effective.In this study, satellite image has been used for extraction of update land use map of Tehran metropolitan. Three different methods (unsupervised classification, supervised classification and visual interpretation) have been utilized for preparation of land use map.
GPS and navigation GPS)، GLONASS، GALILEO
Mohammad Hosein Shafiei; meisam jowkar; Behrooz Safarinejad
Volume 13, Issue 3 , September 2020, , Pages 69-77
Abstract
In this paper a new structure for the inertia measurement unit is presented; the proposed structure consists of three rotary discs around the three main axes in the body, and an accelerometer is mounted on each disc. It is shown in this paper that the proposed structure reduces the effect of disturbing ...
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In this paper a new structure for the inertia measurement unit is presented; the proposed structure consists of three rotary discs around the three main axes in the body, and an accelerometer is mounted on each disc. It is shown in this paper that the proposed structure reduces the effect of disturbing accelerometer parameters, such as constant and variable bias, as well as noise depletion. Due to the proposed rotational structure, it is necessary to continuously sample the accelerometers. In order to use the sampled data, calculations should be performed in discrete mode. In this paper, a method for combining this information is presented. By examining the proposed equations, the successful performance of this method is shown in the reduction of the effect of three constant bias parameters and the bias of the accelerometer and the measured noise. As well as the efficiency of the proposed method for measuring the acceleration of the device using Numerical representation is shown.
S. H. Jalali Naini
Volume 4, Issue 2 , January 2012, , Pages 71-81
Abstract
In this research, an approximate solution of the required velocity with final velocity constraint is derived using linear gravity assumption along the path of current position to the final position vectors. Moreover, an approximate solution for sensitivity matrix of the required velocity with respect ...
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In this research, an approximate solution of the required velocity with final velocity constraint is derived using linear gravity assumption along the path of current position to the final position vectors. Moreover, an approximate solution for sensitivity matrix of the required velocity with respect to the position vector is obtained. The presented solutions are given for a predetermined final time. In this case, for the free final position, the analytical solution is rather more difficult than its fixed final position counterpart. Therefore, three approaches are utilized for approximation of the final position vector. Finally, the obtained solutions are compared to exact numerical one for the spherical-Earth model.
Space subsystems design: (navigation, control, structure and…)
Maziar Shefaee Roshan; Mahdi Ghobadi; Mahdi jafari Nadoushan
Volume 13, Issue 1 , March 2020, , Pages 71-82
Abstract
Using linear programming method in control allocation for attitude control subsystem of spacecraft with redundant thrusters is studied in this paper. The simplex algorithm is utilized as a solver and the Direction Preserving and Bodson’s Reduced size Direction preserving approaches are used as ...
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Using linear programming method in control allocation for attitude control subsystem of spacecraft with redundant thrusters is studied in this paper. The simplex algorithm is utilized as a solver and the Direction Preserving and Bodson’s Reduced size Direction preserving approaches are used as optimal approaches to deal with non admissible solutions. Also, proper functioning of these approaches against thrusters fault phenomenon is evaluated. The results show that the Direction Preserving approache has less computational time and less fuel consuming. However, the Bodson’s Reduced size Direction preserving approache has more computational time and more fuel consuming but less tri-axis tracking error. It should be noted that the PD controller has been used as a spacecraft control rule, and simulations have been made for the number and configuration of the specific thrusters.
investigating space radiation
Sara Shoorian; Hamid Jafari; S. Amir Hossein Feghhi; Gholamreza Aslani
Volume 13, Issue 4 , December 2020, , Pages 71-79
Abstract
The presence of ionizing radiation in the space environment, due to trapped particles, solar particles and cosmic rays can be a serious threat to the proper functioning of electronic components used in satellites and spacecraft. In this work, the leakage current variation of a silicon diode, as the basic ...
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The presence of ionizing radiation in the space environment, due to trapped particles, solar particles and cosmic rays can be a serious threat to the proper functioning of electronic components used in satellites and spacecraft. In this work, the leakage current variation of a silicon diode, as the basic element of many electronic components, has been investigated in the exposure of space protons. For this purpose, the GEANT4 Monte Carlo code has been used to calculate the non-ionizing energy loss in the device. The simulation of electrical parameters for irradiation of space protons were also done by SILVACO software. The results show that the leakage current increases by about 1.85 times the amount of it before irradiation, up to about 96.2 nA/μm by the increase in the proton flux up to 2.1×1012 p/cm2. Irradiation of BPW34 photodiodes under 30 MeV protons was performed to validate the results of simulation.
S. M. M. Sharifi; H. Gholami Mazinan; K. Shahanaghi; M. Karbasian
Volume 5, Issue 1 , April 2012, , Pages 73-80
Abstract
Failures identification of vital and sensitive products and their reliability estimation, before applying affects design improvement of them. On the other hand, because of lack of data,reliability estimation of some systems such asspace products is hard and sometimes impossible. Bayesian networks method ...
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Failures identification of vital and sensitive products and their reliability estimation, before applying affects design improvement of them. On the other hand, because of lack of data,reliability estimation of some systems such asspace products is hard and sometimes impossible. Bayesian networks method is a graphical model with high efficiency for reliability estimation of complex systems and it can also eliminate problem of data shortage. Accordingly, at this paper, first, fault tree related to structure of launch vehicle with liquid fuel has been designed and then mapped into Bayesian networks. Finally using expert decision of system and estimation of model conditional parameters with Monte Carol Markov Chain, reliability of launch vehicle structure has been estimated.
Mohsen Bahrami; Behzad Parsi
Volume 7, Issue 4 , January 2015, , Pages 73-79
Abstract
In this paper a low cost calibration method which can calibrate with measuring the sensor displacement is suggested. To verify this calibration method a two-axis table, which is expensive, with artificial neural network (ANN) for mapping non-linear relationships between the inputs and outputs is used. ...
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In this paper a low cost calibration method which can calibrate with measuring the sensor displacement is suggested. To verify this calibration method a two-axis table, which is expensive, with artificial neural network (ANN) for mapping non-linear relationships between the inputs and outputs is used. The result illustrates the efficiency of this calibration method. In order to design the artificial neural network the MATLAB software is used.
Saeedeh Ya’ghob-nezhad; Seyed Hamed Hashemi Mehne
Volume 9, Issue 1 , May 2016, , Pages 73-89
Abstract
Because of vast applications of Liquid fuel engines in rockets and importance of their functional parameters such as trust, specific impulse and fuel consumption in engine performance, it is needed to be tested in different functional conditions before operation in actual missions. The analysis of test ...
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Because of vast applications of Liquid fuel engines in rockets and importance of their functional parameters such as trust, specific impulse and fuel consumption in engine performance, it is needed to be tested in different functional conditions before operation in actual missions. The analysis of test data used to improve the design, engine troubleshooting and to expand the production program for future rockets. Selecting the suitable injector(s) is the key parameter for improving combustion parameters. With respect to finding the effective ways to analyzing the engine hardware performance without neglecting from their main characteristics, one of the alternatives is doing the hot-fire tests by using a sub scaled engine instead of the full-scale engine. In this research, the design process and manufacturing details of a 300N trust (nominal) micro engine with single swirl Injector is presented. Initial firings using the actual fuel and oxide were not successful. Low fuel flow, low mixing area of the fuel and oxide, and contamination in the self ignition fuel (TR-1) were considered to be the reasons. Overcoming to these problems resulted in successful firing of the subscale engine.
Space subsystems design: (navigation, control, structure and…)
Arian Zakiani; Seyed Hassan Sedighy; Razieh Narimani
Volume 17, Issue 1 , March 2024, , Pages 73-79
Abstract
Due to the limited communication time between LEO satellites and the ground station and large volume of satellite image data, it is necessary to establish a high transmission rate connection. Therefore, the use of a high-efficiency satellite antenna is inevitable. In order to use the limited viewing ...
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Due to the limited communication time between LEO satellites and the ground station and large volume of satellite image data, it is necessary to establish a high transmission rate connection. Therefore, the use of a high-efficiency satellite antenna is inevitable. In order to use the limited viewing time of the satellite, it must be possible to communicate with the ground station at low angles and change the main beam direction of satellite antenna to the direction of the ground station. The proposed array is composed of 8 antenna elements with a compact microstrip feed network. Low profile structure, circular polarization, high gain and low cost specifications of this proposed antenna array, candidate it for conformal array antenna in satellite applications.
