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Number of results: 23
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Abstract

Minimum energy control problem for the fractional positive electrical circuits is formulated and solved. Sufficient conditions for the existence of solution to the problem are established. A procedure for solving of the problem is proposed and illustrated by an example of fractional positive electrical circuit.

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Authors and Affiliations

Tadeusz Kaczorek
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Abstract

The minimum energy control problem for the positive continuous-time linear systems with bounded inputs is formulated and solved. Sufficient conditions for the existence of solution to the problem are established. A procedure for solving of the problem is proposed and illustrated by a numerical example.

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Authors and Affiliations

Tadeusz Kaczorek
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Abstract

In this paper, quanizted multisine inputs for a maneuver with simultaneous elevator, aileron and rudder deflections are presented. The inputs were designed for 9 quantization levels. A nonlinear aircraft model was exited with the designed inputs and its stability and control derivatives were identified. Time domain output error method with maximum likelihood principle and a linear aircraft model were used to perform parameter estimation. Visual match and relative standard deviations of the estimates were used to validate the results for each quantization level for clean signals and signals with measurement noise present in the data. The noise was included into both output and input signals. It was shown that it is possible to obtain accurate results when simultaneous flight controls deflections are quantized and noise is present in the data.

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Authors and Affiliations

P. Lichota
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Abstract

To achieve better precision of features generated using the micro-electrical discharge machining (micro-EDM), there is a necessity to minimize the wear of the tool electrode, because a change in the dimensions of the electrode is reflected directly or indirectly on the feature. This paper presents a novel modeling and analysis approach of the tool wear in micro-EDM using a systematic statistical method exemplifying the influences of capacitance, feed rate and voltage on the tool wear ratio. The association between tool wear ratio and the input factors is comprehended by using main effect plots, interaction effects and regression analysis. A maximum variation of four-fold in the tool wear ratio have been observed which indicated that the tool wear ratio varies significantly over the trials. As the capacitance increases from 1 to 10 nF, the increase in tool wear ratio is by 33%. An increase in voltage as well as capacitance would lead to an increase in the number of charged particles, the number of collisions among them, which further enhances the transfer of the proportion of heat energy to the tool surface. Furthermore, to model the tool wear phenomenon, a egression relationship between tool wear ratio and the process inputs has been developed.

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Authors and Affiliations

Govindan Puthumana
1

  1. Technical University of Denmark, Lyngby, Denmark
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Abstract

Generalized observers are proposed to relax the existing conditions required to design Luenberger observers for rectangular linear descriptor systems with unknown inputs. The current work is focused on designing index one generalized observers, which can be naturally extended to higher indexes. Sufficient conditions in terms of system operators for the existence of generalized observers are given and proved. Orthogonal transformations are used to derive the results. A physical model is presented to show the usefulness of the proposed theory.
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Authors and Affiliations

Abhinav Kumar
1
Mahendra Kumar Gupta
1 2

  1. Department of Mathematics, National Institute of Technology Jamshedpur, Jharkhand, India
  2. School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Argul, Khordha, Odisha, 752050 – India
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Abstract

A three-level multi-input DC/DC converter is proposed to solve the problems of complex interface circuit structure and high economic cost for multi-source access to the joint power supply distribution system. In this structure, multiple dc sources are integrated into a three-level DC/DC converter. In comparison with the two-stage counterpart, two active switches and boost diodes are eliminated, while two blocking diodes are added to block the reverse current from the dc-link capacitors. In addition, when the input inductors work in the discontinuous conduction mode, power sharing among different input sources can be achieved by properly selecting the inductance value. The working principle of the converter is analyzed by introducing nine working modes in detail and deriving the steady-state relationship expressions. The parameter range of the element is determined and the design process of a group of dynamic parameter values is shown. Finally, the power electronics real-time simulation platform is built based on StarSim HIL and the corresponding experimental waveforms are given to verify the topology and analysis.
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Authors and Affiliations

Jingjing Tian
1
Jiaoping Qu
1
ORCID: ORCID
Feng Zhao
1
Xiaoqiang Chen
1 2
Ying Wang
1 2
ORCID: ORCID
Yang Gan
1

  1. School of Automation & Electrical Engineering, Lanzhou Jiaotong University, Lanzhou, China
  2. Key Laboratory of Opto-technology and Intelligent Control, Lanzhou Jiaotong University, Ministry of Education, Lanzhou, China
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Abstract

The continuous real-time monitoring of diverse physical parameters using biosignals like ECG and EEG requires the biomedical sensors. Such sensor consists of analog frontend unit for which low noise and low power Operational transconductance amplifier (OTA) is essential. In this paper, the novel chopper-stabilized bio-potential amplifier is proposed. The chopper stabilization technique is used to reduce the offset and flicker noise. Further, the OTA is likewise comprised of a method to enhance the input impedance without consuming more power. Also, the ripple reduction technique is used at the output branch of the OTA. The designed amplifier consumes 5.5 μW power with the mid-band gain of 40dB. The pass-band for the designed amplifier is 0.1Hz to 1KHz. The input impedance is likewise boosted with the proposed method. The noise is 42 nV/√H z with CMRR of 82 dB. All simulations are carried out in 180nm parameters.
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Authors and Affiliations

Ankit Adesara
1
Amisha Naik
1

  1. Nirma University, Indian Institute of Information Technology, Surat, India
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Abstract

The main goal of estimating models for industrial applications is to guarantee the cheapest system identification. The requirements for the identification experiment should not be allowed to affect product quality under normal operating conditions. This paper deals with ensuring the required liquid levels of the cascade system tanks using the model predictive control (MPC) method. The MPC strategy was extended with the Kalman filter (KF) to predict the system’s succeeding states subject to a reference trajectory in the presence of both process and measurement noise covariances. The main contribution is to use the application-oriented input design to update the parameters of the model during system degradation. This framework delivers the least-costly identification experiment and guarantees high performance of the system with the updated model. The methods presented are evaluated both in the experiments on a real process and in the computer simulations. The results of the robust MPC application for cascade system water levels control are discussed.
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Authors and Affiliations

Wiktor Jakowluk
1
ORCID: ORCID
Sławomir Jaszczak
2

  1. Bialystok University of Technology, Faculty of Computer Science, Wiejska 45A, 15-351 Białystok, Poland
  2. West Pomeranian University of Technology in Szczecin, Faculty of Computer Science and Information Technology, Żołnierska 49, ˙71-210 Szczecin, Poland
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Abstract

Artificial neural network (ANN), a Computational tool that is frequently applied in the modeling and simulation of manufacturing processes. The emerging forming technique of sheet metal which is typically called single point incremental forming (SPIF) comes into the map and the research interest towards its technological parameters. The surface quality of the end product is a major issue in SPIF, which is more critical with the hard metals. The part of the brass metal is demanded in many industrial uses because of its high load-carrying capacity and its wear resistance property. Considering the industrial interest and demand of the brass metal products, the present study is done with the SPIF experiment on calamine brass Cu67Zn33 followed by an ANN analysis for predicting the absolute surface roughness. The modeling result shows a close agreement with the measured data. The minimum and maximum errors are found in experiment 3 and experiment 7 respectively. The error of predicted roughness is found in the range of –30.87 to 20.23 and the overall coefficient of performance of ANN modeling is 0.947 which is quite acceptable.
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Authors and Affiliations

Manish Oraon
1
Vinay Sharma
1

  1. Birla Institute of Technology, Faculty of Production Engineering, India
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Abstract

Large-signal input characteristics of three DC–DC converter types: buck, boost and flyback working in the discontinuous conduction mode (DCM), obtained by precise large signal PSpice simulations, calculations based on averaged models and measurements are presented. The parasitic resistances of the converter components are included in the simulations. The specific features of the input characteristics in theDCMand the differences between the continuous conduction mode (CCM) and DCM are discussed.

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Authors and Affiliations

Włodzimierz Janke
ORCID: ORCID
Maciej Bączek
ORCID: ORCID
Jarosław Kraśniewski
ORCID: ORCID
Marcin Walczak
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Abstract

Large-signal input characteristics of three DC–DC converter types: buck, boost and flyback working in the continuous conduction mode (CCM), obtained by simulations and measurements are investigated. The results of investigations are presented in the form of the analytical formulas and the exemplary results of the measurements and two forms of simulations: based on the full description of the converter components and on the averaged models. The parasitic resistances of the converter components are included in the simulations and their influence on the simulation results is discussed.

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Authors and Affiliations

Włodzimierz Janke
ORCID: ORCID
Maciej Bączek
ORCID: ORCID
Jarosław Kraśniewski
ORCID: ORCID
Marcin Walczak
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Abstract

Over the past two decades, artificial neural networks (ANN) have exhibited a significant progress in predicting and modeling non-linear hydrological applications, such as the rainfall-runoff process which can provide useful contribution to water resources planning and management. This research aims to test the practicability of using ANNs with various input configurations to model the rainfall-runoff relationship in the Seybouse basin located in a semi-arid region in Algeria. Initially, the ANNs were developed for six sub-basins, and then for the complete watershed, considering four different input configurations. The 1st (ANN IP) considers only precipitation as an input variable for the daily flow simulation. The 2nd (ANN II) considers the 2nd variable in the model input with precipitation; it is one of the meteorological parameters (evapotranspiration, temperature, humidity, or wind speed). The third (ANN IIIP,T,HUM) considers a combination of temperature, humidity, and precipitation. The last (ANN VP,ET,T,HUM,Vw) consists in collating different meteorological parameters with precipitation as an input variable. ANN models are made for the whole basin with the same configurations as specified above. Better flow simulations were provided by (ANN IIP,T) and (ANN IIP,Vw) for the two stations of Medjez-Amar II and Bordj-Sabath, respectively. However, the (ANN VP,ET,T,HUM,Vw)’s application for the other stations and also for the entire basin reflects a strategy for the flow simulation and shows enhancement in the prediction accuracy over the other models studied. This has shown and confirmed that the more input variables, as more efficient the ANN model is.
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Authors and Affiliations

Yamina Aoulmi
1
ORCID: ORCID
Nadir Marouf
1
ORCID: ORCID
Mohamed Amireche
1
ORCID: ORCID

  1. University of Larbi-Ben-M’hidi, Faculty of Sciences and Applied Sciences, Department of Hydraulic, Laboratory of Ecology and Environment, PO Box 358, 04000 Oum El Bouaghi, Algeria
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Abstract

7075-T6 Al and AZ31B Mg dissimilar alloys were friction stir lap welded with or without a Zn filler, and the effect of heat input on the joint quality was systematically studied. The experimental and finite element simulation results displayed that the formation characteristics and microstructures of the joint with or without the Zn filler were significantly affected by the heat input. The tensile shear load of joint with or without the Zn filler increased first and then decreased with the decrease of the welding speed from 200 to 50 mm/min. Moreover, the peak temperature in the stir zone was significantly decreased by the Zn filler addition, and the high temperature zone narrowed along the plate thickness direction. These changes of heat input made that longer mixing region boundary length and larger effective lap width were attained as the Zn filler was used. In addition, due to the replacement of Al-Mg intermetallic compounds (IMCs) by Al-Mg-Zn and Mg-Zn IMCs which were less harmful to the joint, the tensile shear load of the joint with the Zn filler was obviously enhanced compared to that of the joint without the Zn filler at each welding speed. The maximum tensile shear load of 7.2 kN was obtained at the welding speed of 100 mm/min.
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Authors and Affiliations

Huaxia Zhao
1
ORCID: ORCID
Peng Gong
2
ORCID: ORCID
Shude Ji
2
ORCID: ORCID
Xue Gong
2
ORCID: ORCID

  1. AVIC Manufacturing Technology Institute, Beijing 100024, P. R. China
  2. Shenyang Aerospace University, College of Aerospace Engineering, Shenyang 110136, P. R. China
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Abstract

The coarse-grained heat-affected zone specimens of X80 pipeline steel were produced by welding thermal simulation under different heat inputs of 10, 30, and 55 kJ/cm to study the effects of heat input on microstructure evolution and corrosion characterization. The corrosion resistance of coarse-grained heat-affected zones was poorer than that of base metal due to less homogenous in the former. For 10 kJ/cm coarse-grained heat-affected zone, the corrosion resistance was poorer than the others due to the more adsorption hydrogen around the needle-like martensite/austenite constituents and greater galvanic driving force between the needle-like martensite/austenite constituents and ferrite. In carbonate/bicarbonate solution, better corrosion resistance for coarse-grained heat-affected zones was obtained when the heat input is 30 kJ/cm, which can be attributed to the severe coarse martensite/austenite constituents for 55 kJ/cm coarse-grained heat-affected zone. In the H2S environment, the better corrosion resistance for coarse-grained heat-affected zone was obtained when the heat input is 55 kJ/cm, which can be attributed to the protective effect of corrosion products. In addition, the high content of M/A constituents for 30 kJ/cm CGHAZ was good for hydrogen adsorption, which was adverse to the corrosion resistance in acid environments.
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Authors and Affiliations

Xue-Mei Wang
1 2
ORCID: ORCID
Wei Zhao
1 2 3
ORCID: ORCID
Kai Chen
1 2
ORCID: ORCID
Zhen Li
1 2
ORCID: ORCID

  1. Qilu University of Technology (Shandong Academy of Sciences), School of Mechanical & Automotive Engineering, China
  2. Shandong Institute of Mechanical Design and Research, China
  3. School of Materials Science and Engineering, Tianjin University, China
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Abstract

The paper presents a low noise voltage FET amplifier for low frequency noise measurements. It was built using two stages of an op amp transimpedance amplifier. To reduce voltage noise, eight-paralleled low noise discrete JFETs were used in the first stage. The designed amplifier was then compared to commercial ones. Its measured value of voltage noise spectral density is around 24 nV/√ Hz, 3 nV/√ Hz, 0.95 nV/√Hz and 0.6 nV/√ Hz at the frequency of 0.1, 1, 10 and 100 Hz, respectively. A −3 dB frequency response is from ∼ 20 mHz to ∼ 600 kHz.

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Authors and Affiliations

Krzysztof Achtenberg
ORCID: ORCID
Janusz Mikołajczyk
ORCID: ORCID
Zbigniew Bielecki
ORCID: ORCID
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Abstract

This paper presents a novel measurement method and briefly discusses the basic properties of direction of arrival (DoA) measurement in a multiple-input multiple-output (MIMO) radar system by using orthogonality with time-division multiplexing (TDM), where only one transmitting antenna element is active in each time slot. This paper presents the mathematical model of the TDM-MIMO radar operating at 10 GHz, transmitting a string of pulses, the method of transmitting and receiving the signal, and the method of measuring the angle of arrival of the signal based on the use of the Capon algorithm and its modifications. Finally, the correctness of the theory, algorithm and method of measuring the direction of arrival of the signal is verified by experimental simulation. The work discussed in this paper is of great significance to practically demonstrate the capabilities of the TDM MIMO radar sensor in practical implementations like reconnaissance and electronic warfare systems.
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Authors and Affiliations

Anna Ślesicka
1
Adam Kawalec
2
Błażej Ślesicki
3

  1. Military University of Aviation, Institute of Navigation, Dywizjonu 303 no. 35, 08-521 Deblin, Poland
  2. Military University of Technology, Faculty of Mechatronics, Armament and Aerospace, Department of Anti-AircraftMissile Sets, gen. S. Kaliskiego 2, 00-908 Warsaw, Poland
  3. Military University of Aviation, Faculty of Aviation, Department of Avionics and Control Systems,Dywizjonu 303 no. 35, 08-521 Deblin, Poland
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Abstract

The model predictive control (MPC) technique has been widely applied in a large number of industrial plants. Optimal input design should guarantee acceptable model parameter estimates while still providing for low experimental effort. The goal of this work is to investigate an application-oriented identification experiment that satisfies the performance objectives of the implementation of the model. A- and D-optimal input signal design methods for a non-linear liquid two-tank model are presented in this paper. The excitation signal is obtained using a finite impulse response filter (FIR) with respect to the accepted application degradation and the input power constraint. The MPC controller is then used to control the liquid levels of the double tank system subject to the reference trajectory. The MPC scheme is built based on the linearized and discretized model of the system to predict the system’s succeeding outputs with reference to the future input signal. The novelty of this model-based method consists in including the experiment cost in input design through the objective function. The proposed framework is illustrated by means of numerical examples, and simulation results are discussed.

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Authors and Affiliations

W. Jakowluk
M. Świercz
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Abstract

This paper presents an interpretation of sedimentologic, paleomagnetic, and geochemical data collected in the Upper Kimmeridgian–Valanginian carbonates of the Giewont series (Giewont and Mały Giewont sections, High-Tatric succession, Western Tatra Mountains, Poland). The studied succession provides insight into the sedimentary conditions prevailing in the South Tatric Ridge (Tatricum), a submarine elevation located between the Zliechov Basin (Fatricum) and the Vahic (=South Penninic) Ocean. The sedimentary sequence includes micrites, pseudonodular limestones, cyanoid packstones, lithoclastic packstone, and encrinites. The results are discussed with regards to their significance for detrital input, paleoclimate, and paleoproductivity, which in turn are considered in the context of both local and regional paleoenvironmental trends and events. The greatest depositional depths during the latest Kimmeridgian–earliest Tithonian are documented by the occurrence of pseudonodular limestones. A Tithonian shallowing trend is demonstrated via the increasing size and roundness of cyanoids, while the final (?)emergence and erosion in the South Tatric Ridge is documented by earliest Cretaceous disconformities. This process might have been related to both falling sea-level during the major eustatic regressive cycle and tectonic uplift caused by the mutually related (re)activation in the Neotethyan Collision Belt and rifting in the Ligurian-Penninic-Vahic Oceans. The highest lithogenic influx (although still low; max 0.5% of Al content) during the Late Kimmeridgian is considered as associated with relatively humid climate conditions, whereas a subsequent decreasing trend is thought to result from aridification during the latest Kimmeridgian–earliest Tithonian. Ultimately, deposition in the High-Tatric zone was affected by both large-scale environmental perturbations characteristic of the latest Jurassic (climate changes, variations in seawater pH, monsoonal upwelling, lithogenic input, etc.), as well as local sedimentary controls, predominantly the oxygenation state of bottom waters and tectonic movements.

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Authors and Affiliations

Damian Gerard Lodowski
1
Jacek Grabowski
2

  1. University of Warsaw, Faculty of Geology, Żwirki i Wigury 93, 02-089 Warszawa, Poland
  2. Polish Geological Institute-National Research Institute, Rakowiecka 4, 00-975 Warszawa, Poland
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Abstract

One of the most popular heuristics used to solve the permutation flowshop scheduling problem (PFSP) is the NEH algorithm. The reasons for the NEH popularity are its simplicity, short calculation time, and good-quality approximations of the optimal solution for a wide range of PFSP instances. Since its development, many works have been published analysing various aspects of its performance and proposing its improvements. The NEH algorithm includes, however, one unspecified and unexamined feature that is related to the order of jobs with equal values of total processing time in an initial sequence. We examined this NEH aspect using all instances from Taillard’s and VRF benchmark sets. As presented in this paper, the sorting operation has a significant impact on the results obtained by the NEH algorithm. The reason for this is primarily the input sequence of jobs, but also the sorting algorithm itself. Following this observation, we have proposed two modifications of the original NEH algorithm dealing with sequencing of jobs with equal total processing time. Unfortunately, the simple procedures used did not always give better results than the classical NEH algorithm, which means that the problem of sequencing jobs with equal total processing time needs a smart approach and this is one of the promising directions for further research.
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Authors and Affiliations

Radosław Puka
1
Jan Duda
1
A. Stawowy
ORCID: ORCID

  1. Bialystok University of Technology, Faculty of Management Engineering, Poland
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Abstract

Underwater Acoustic Communications (UWAC) is an emerging technology in the field of underwater communications, and it is challenging because of the signal attenuation of the sound waves. Multiple Input and Multiple- Output (MIMO) is introduced in UWAC because of its support in enhancing the data throughput even under the conditions of interference, signal fading, and multipath. The paper presents the concept and analysis of 2× 2 MIMO UWAC systems that uses a 4- QAM spatial modulation scheme thus minimizing the decoding complexity and overcoming the Inter Channel Interference (IChI). Bit Error Rate (BER) investigation is carried out over different link distances under acoustic Line of Sight (LOS). The utilization of Zero Forcing (ZF) and Vertical-Bell Laboratories Layered Space-Time (VBLAST) equalizers, which estimates the transmitted data proves a success of removing Inter Symbol Interference (ISI). The ISI caused due to multipath effect and scattering in UWAC can be reduced by iterative process considered in VBLAST. A study is made on how the distance between the transmitter and the receiver and the Doppler Effect has its impact on the performance of the system.

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Authors and Affiliations

B. Pranitha
L. Anjaneyulu
Hoa Le Minh
Nauman Aslam
V. Sandeep Kumar
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Abstract

This paper demonstrates a low-profile, wide-band, two-element, frequency-reconfigurable MIMO antenna that is suitable for diverse wireless applications of 4G and 5G such as WLAN/Bluetooth (2.4–2.5 GHz), WLAN (2.4–2.484 GHz, 5.15– 5.35 GHz, and 5.725–5.825 GHz), WiMAX (3.3–3.69 GHz and 5.25–5.85 GHz), Sub6GHz band proposed for 5G (3.4–3.6 GHz, 3.6-3.8GHz and 4.4–4.99 GHz), INSAT and satellite X-band(6 to 9.6 GHz). Proposed MIMO favour effortless switching between multiple bands ranging from 2.2 to 9.4 GHz without causing any interference. Both antenna elements in a MIMO array are made up of a single module comprised of a slot-loaded patch and a defective structured ground. Two PIN diodes are placed in the preset position of the ground defect to achieve frequencyreconfigurable qualities. The suggested MIMO antenna has a size of 62 ×25 ×1.5 mm3. Previous reconfigurable MIMO designs improved isolation using a meander line resonator, faulty ground structures, or self-isolation approaches. To attain the isolation requirements of modern devices, stub approach is introduced in proposed design. Without use of stub, simulated isolation is 15dB. The addition of a stub improved isolation even more. At six resonances, measured isolation is greater than 18 dB, the computed correlation coefficient is below 0.0065, and diversity gain is over 9.8 dB.
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Authors and Affiliations

Shivleela Mudda
1
Gayathri K M
1
Mallikarjun M
2

  1. Dayananda Sagar University, Bangalore, India
  2. Srinidhi Institute of Science and Technology, Hyderabad (Telangana), India

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