Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512200
G. Mehdi, Hu Anyong, Miao Jun-gang
The design of a narrowband low noise amplifier (LNA) module at Ka band is presented. A low noise MMIC chip fabricated in GaAs pHEMT process is employed. Since the LNA is narrowband, its matching is sensitive to parasitic associated with the bond-wire interconnects and the fixture connectors. A T-type matching network which comprises of a high-low impedance lines is realized on microstrip substrate to nullify the bond-wires inductance. The planar structures in the design are simulated in ADS Momentum® while the bond-wires are modeled in a FEM based full-wave simulator. The design, assembly and packaging of the module are described. The measured results exhibit 23.5 dB gain at 35 GHz frequency. The 1:2 VSWR bandwidth is 2 GHz. The measured noise figure is 3.5 dB.
{"title":"A narrowband low noise amplifier for passive imaging systems","authors":"G. Mehdi, Hu Anyong, Miao Jun-gang","doi":"10.1109/IBCAST.2013.6512200","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512200","url":null,"abstract":"The design of a narrowband low noise amplifier (LNA) module at Ka band is presented. A low noise MMIC chip fabricated in GaAs pHEMT process is employed. Since the LNA is narrowband, its matching is sensitive to parasitic associated with the bond-wire interconnects and the fixture connectors. A T-type matching network which comprises of a high-low impedance lines is realized on microstrip substrate to nullify the bond-wires inductance. The planar structures in the design are simulated in ADS Momentum® while the bond-wires are modeled in a FEM based full-wave simulator. The design, assembly and packaging of the module are described. The measured results exhibit 23.5 dB gain at 35 GHz frequency. The 1:2 VSWR bandwidth is 2 GHz. The measured noise figure is 3.5 dB.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115410802","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512146
M. Usman Hafeez, M. Ajmal, T. A. Khan, Z. Khan
Structure excitation plays a key role in evaluating the stability of the aircraft during flutter flight test. Various techniques are used for the excitation of aircraft during flutter flight test. Each technique has its own merits and demerits depending upon the type and application of exciters. This paper describes the comparison of rotating cylinder vane type excitation system (external) with free air turbulence (natural). Different performance parameters like excitation force, frequency range and phase difference of the flutter exciters were evaluated based on the flight test data. Free air turbulence was able to excite low frequency modes (<; 20 Hz) with small amplitudes. Whereas the rotating cylinder system excited the complete required range (up to 50 Hz) with significantly higher amplitudes. Major difference can be seen in the performance like high signal to noise ratio, suitable identification of elastic modes, appropriate in-phase and out-of-phase excitation to the aircraft as compared to free air turbulence. Rotating cylinder excitation systems is a more efficient way of doing flutter flight testing as it results in significant reduction in time of flight tests and better estimation of structural identification.
{"title":"Comparison of vane type external excitation and Free Air Turbulence Methods for flutter flight testing","authors":"M. Usman Hafeez, M. Ajmal, T. A. Khan, Z. Khan","doi":"10.1109/IBCAST.2013.6512146","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512146","url":null,"abstract":"Structure excitation plays a key role in evaluating the stability of the aircraft during flutter flight test. Various techniques are used for the excitation of aircraft during flutter flight test. Each technique has its own merits and demerits depending upon the type and application of exciters. This paper describes the comparison of rotating cylinder vane type excitation system (external) with free air turbulence (natural). Different performance parameters like excitation force, frequency range and phase difference of the flutter exciters were evaluated based on the flight test data. Free air turbulence was able to excite low frequency modes (<; 20 Hz) with small amplitudes. Whereas the rotating cylinder system excited the complete required range (up to 50 Hz) with significantly higher amplitudes. Major difference can be seen in the performance like high signal to noise ratio, suitable identification of elastic modes, appropriate in-phase and out-of-phase excitation to the aircraft as compared to free air turbulence. Rotating cylinder excitation systems is a more efficient way of doing flutter flight testing as it results in significant reduction in time of flight tests and better estimation of structural identification.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"30 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125689687","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512144
M. F. Zafar, Z. Zaheer, J. Khurshid
The richness and apparent stability of the iris texture make it a robust biometric trait for personal authentication. The performance of an automated iris recognition system is affected by the accuracy of the segmentation process used to localize the iris structure. In case of wrong segmentation, wrong features will be extracted and hence, may lead to false identification results. Most of the authors propose Circular Hough Transform to localize the boundary of IRIS. But the problem with this technique is its high consumption of time and memory. It also requires a precise estimated range of the boundary and it fails to localize the IRIS if the correct estimation is not provided. The proposed technique follows a basic strategy and obtains the major boundaries, by using canny edge detector. Features have been extracted using Curvelets Transform; Principal Component Analysis is then used to reduce the dimension of the features. Then SVM has been used as classifier. The implementation of recognition method has shown encouraging results.
{"title":"Novel iris segmentation and recognition system for human identification","authors":"M. F. Zafar, Z. Zaheer, J. Khurshid","doi":"10.1109/IBCAST.2013.6512144","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512144","url":null,"abstract":"The richness and apparent stability of the iris texture make it a robust biometric trait for personal authentication. The performance of an automated iris recognition system is affected by the accuracy of the segmentation process used to localize the iris structure. In case of wrong segmentation, wrong features will be extracted and hence, may lead to false identification results. Most of the authors propose Circular Hough Transform to localize the boundary of IRIS. But the problem with this technique is its high consumption of time and memory. It also requires a precise estimated range of the boundary and it fails to localize the IRIS if the correct estimation is not provided. The proposed technique follows a basic strategy and obtains the major boundaries, by using canny edge detector. Features have been extracted using Curvelets Transform; Principal Component Analysis is then used to reduce the dimension of the features. Then SVM has been used as classifier. The implementation of recognition method has shown encouraging results.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114832551","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512120
Hui Li
The breadth of supramolecular chemistry has progressively increased with the synthesis of numerous unique supramolecules each year. Coordination-driven self-assembly that employ strong and directional metal-ligand bonds for the assembly process is a powerful and facile method to construct the functional and advance materials. This review has scanned some examples in literatures and reported some research results in my group, which included background, luminescence material, magnetic material, conductive material and multifunctional materials.
{"title":"Functional materials based on supramolecular coordination: Structure and properties","authors":"Hui Li","doi":"10.1109/IBCAST.2013.6512120","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512120","url":null,"abstract":"The breadth of supramolecular chemistry has progressively increased with the synthesis of numerous unique supramolecules each year. Coordination-driven self-assembly that employ strong and directional metal-ligand bonds for the assembly process is a powerful and facile method to construct the functional and advance materials. This review has scanned some examples in literatures and reported some research results in my group, which included background, luminescence material, magnetic material, conductive material and multifunctional materials.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124345599","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512165
S. Afzal, A. Baig, M. Rafique
Different kinds of control surfaces are being used on supersonic projectiles. Grid fins (GF) and Wrapped around fins (WAF) are two important control surfaces that have been used on many projectiles. Both have different aerodynamics characteristics associated with them. Viscous computational fluid dynamic simulations were used to compute the flow field around projectiles having GF and WAF mounted at the end of a 10 diameter long body having ogive nose. The computed aerodynamics coefficients are in good agreement with the available experimental data. The performed simulations help in understanding the flow physics associated with these surfaces. The variation of center of pressure with Mach has been shown to get a comparison of both configurations.
{"title":"Aerodynamics of projectiles with wrapped around and grid fins","authors":"S. Afzal, A. Baig, M. Rafique","doi":"10.1109/IBCAST.2013.6512165","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512165","url":null,"abstract":"Different kinds of control surfaces are being used on supersonic projectiles. Grid fins (GF) and Wrapped around fins (WAF) are two important control surfaces that have been used on many projectiles. Both have different aerodynamics characteristics associated with them. Viscous computational fluid dynamic simulations were used to compute the flow field around projectiles having GF and WAF mounted at the end of a 10 diameter long body having ogive nose. The computed aerodynamics coefficients are in good agreement with the available experimental data. The performed simulations help in understanding the flow physics associated with these surfaces. The variation of center of pressure with Mach has been shown to get a comparison of both configurations.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"518 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123107216","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512167
S. Khalid, Jin Zhiguang, Tang Fuding, Zhang Liang, A. Z. Chaudhry
Numerical simulation models are commonly used nowadays to quantify the effects of tidal extraction specifically in tidal systems. Vertical axis tidal turbine (VATT) is one of the major tools to harness the tidal energy. The development of accurate and reliable simulation scheme is the aim of researchers to minimize the computational time as well as to minimize the testing and experimental cost. In this paper a two-way Fluid Structure Interaction (FSI) coupling scheme is developed for the hydrodynamic analysis of VATT. Main hydrodynamic parameters like torque T, combined moment CM, coefficients of performance CP and coefficient of torque CT, etc. are investigated. This method combines fluid simulation with structure dynamic analysis. This method is based on a general computational fluid dynamic (CFD) code that solves the Navier Stokes Equations by finite volume method. A technique used to couple the CFD code to structural dynamic program to calculate the airfoil displacements due to the hydrodynamics forces and updating the grid at each time step. At the end the difference between the CFX independent simulations results and two-way FSI results are compared to highlight the difference.
{"title":"CFD simulation of vertical axis tidal turbine using two-way fluid structure interaction method","authors":"S. Khalid, Jin Zhiguang, Tang Fuding, Zhang Liang, A. Z. Chaudhry","doi":"10.1109/IBCAST.2013.6512167","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512167","url":null,"abstract":"Numerical simulation models are commonly used nowadays to quantify the effects of tidal extraction specifically in tidal systems. Vertical axis tidal turbine (VATT) is one of the major tools to harness the tidal energy. The development of accurate and reliable simulation scheme is the aim of researchers to minimize the computational time as well as to minimize the testing and experimental cost. In this paper a two-way Fluid Structure Interaction (FSI) coupling scheme is developed for the hydrodynamic analysis of VATT. Main hydrodynamic parameters like torque T, combined moment CM, coefficients of performance CP and coefficient of torque CT, etc. are investigated. This method combines fluid simulation with structure dynamic analysis. This method is based on a general computational fluid dynamic (CFD) code that solves the Navier Stokes Equations by finite volume method. A technique used to couple the CFD code to structural dynamic program to calculate the airfoil displacements due to the hydrodynamics forces and updating the grid at each time step. At the end the difference between the CFX independent simulations results and two-way FSI results are compared to highlight the difference.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"40 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116984230","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512151
M. Shafiq, M. Pericàs, N. Navarro, E. Ayguadé
In the recent years streaming accelerators like GPUs have been pop-up as an effective step towards parallel computing. The wish-list for these devices span from having a support for thousands of small cores to a nature very close to the general purpose computing. This makes the design space very vast for the future accelerators containing thousands of parallel streaming cores. This complicates to exercise a right choice of the architectural configuration for the next generation devices. However, accurate design space exploration tools developed for the massively parallel architectures can ease this task. The main objectives of this work are twofold. (i) We present a complete environment of a trace driven simulator named SArcs (Streaming Architectural Simulator) for the streaming accelerators. (ii) We use our simulation tool-chain for the design space explorations of the GPU like streaming architectures. Our design space explorations for different architectural aspects of a GPU like device a e with reference to a base line established for NVIDIA's Fermi architecture (GPU Tesla C2050). The explored aspects include the performation effects by the variations in the configurations of Streaming Multiprocessors Global Memory Bandwidth, Channles between SMs down to Memory Hierarchy and Cache Hierarchy. The explorations are performed using application kernels from Vector Reduction, 2D-Convolution. Matrix-Matrix Multiplication and 3D-Stencil. Results show that the configurations of the computational resources for the current Fermi GPU device can deliver higher performance with further improvement in the global memory bandwidth for the same device.
近年来，像gpu这样的流加速器已经成为并行计算的有效手段。这些设备的愿望清单涵盖了从支持数千个小内核到非常接近通用计算的性质。这使得包含数千个并行流核的未来加速器的设计空间非常大。这使得为下一代设备正确选择体系结构配置变得复杂。然而，为大规模并行架构开发的精确的设计空间探索工具可以简化这一任务。这项工作的主要目标是双重的。(i)我们为流加速器提供了一个名为SArcs(流架构模拟器)的跟踪驱动模拟器的完整环境。(ii)我们将模拟工具链用于GPU的设计空间探索，如流架构。我们对GPU类设备的不同架构方面的设计空间探索是参考NVIDIA的费米架构(GPU Tesla C2050)建立的基线。研究的方面包括流多处理器全局内存带宽、SMs之间的通道到内存层次结构和缓存层次结构的配置变化对性能的影响。探索是使用矢量还原，二维卷积的应用程序内核进行的。矩阵-矩阵乘法和3d模板。结果表明，当前费米GPU设备的计算资源配置可以提供更高的性能，并进一步提高相同设备的全局内存带宽。
{"title":"Design space explorations for streaming accelerators using Streaming Architectural Simulator","authors":"M. Shafiq, M. Pericàs, N. Navarro, E. Ayguadé","doi":"10.1109/IBCAST.2013.6512151","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512151","url":null,"abstract":"In the recent years streaming accelerators like GPUs have been pop-up as an effective step towards parallel computing. The wish-list for these devices span from having a support for thousands of small cores to a nature very close to the general purpose computing. This makes the design space very vast for the future accelerators containing thousands of parallel streaming cores. This complicates to exercise a right choice of the architectural configuration for the next generation devices. However, accurate design space exploration tools developed for the massively parallel architectures can ease this task. The main objectives of this work are twofold. (i) We present a complete environment of a trace driven simulator named SArcs (Streaming Architectural Simulator) for the streaming accelerators. (ii) We use our simulation tool-chain for the design space explorations of the GPU like streaming architectures. Our design space explorations for different architectural aspects of a GPU like device a e with reference to a base line established for NVIDIA's Fermi architecture (GPU Tesla C2050). The explored aspects include the performation effects by the variations in the configurations of Streaming Multiprocessors Global Memory Bandwidth, Channles between SMs down to Memory Hierarchy and Cache Hierarchy. The explorations are performed using application kernels from Vector Reduction, 2D-Convolution. Matrix-Matrix Multiplication and 3D-Stencil. Results show that the configurations of the computational resources for the current Fermi GPU device can deliver higher performance with further improvement in the global memory bandwidth for the same device.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126436989","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512124
U. A. Dar, Zhang Weihong, Xu Yingjie
In this study, the perforation failure of honeycomb sandwich structures is numerically simulated by using homogenized equivalent model. The high velocity impact behavior of aluminum honeycomb core with reinforced carbon/epoxy face sheets is modeled by using commercial finite element (FE) analysis code AUTODYN-3D. It is observed that the detailed three dimensional FE modeling of honeycomb core is complex, time consuming and computationally expensive. A simplified hexagonal honeycomb equivalent numerical model with relatively less computational time and acceptable degree of accuracy is proposed in this paper. The equivalent numerical model is based on P-alpha (Pα) equation of state for porous materials. In this model, it is assumed that honeycomb core is isotropic homogeneous porous medium in which all the pores are uniformly distributed. For the purpose of validation, the simulation results of detailed and equivalent honeycomb numerical models are compared with available experimental results in terms of ballistic limit, energy absorption, residual velocity and contact time. The results show that the equivalent honeycomb model closely predicts the perforation behavior for various impact velocities and takes considerably less computational time than detailed honeycomb model.
{"title":"Modeling the perforation failure of honeycomb sandwich structures through numerical homogenization","authors":"U. A. Dar, Zhang Weihong, Xu Yingjie","doi":"10.1109/IBCAST.2013.6512124","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512124","url":null,"abstract":"In this study, the perforation failure of honeycomb sandwich structures is numerically simulated by using homogenized equivalent model. The high velocity impact behavior of aluminum honeycomb core with reinforced carbon/epoxy face sheets is modeled by using commercial finite element (FE) analysis code AUTODYN-3D. It is observed that the detailed three dimensional FE modeling of honeycomb core is complex, time consuming and computationally expensive. A simplified hexagonal honeycomb equivalent numerical model with relatively less computational time and acceptable degree of accuracy is proposed in this paper. The equivalent numerical model is based on P-alpha (Pα) equation of state for porous materials. In this model, it is assumed that honeycomb core is isotropic homogeneous porous medium in which all the pores are uniformly distributed. For the purpose of validation, the simulation results of detailed and equivalent honeycomb numerical models are compared with available experimental results in terms of ballistic limit, energy absorption, residual velocity and contact time. The results show that the equivalent honeycomb model closely predicts the perforation behavior for various impact velocities and takes considerably less computational time than detailed honeycomb model.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127358577","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512177
M. Yousaf, M. Ahmad
Oscillator is an integral and vital part of any RF/Microwave communication system. With an ever increasing demand of sophisticated applications in communication domain, the need for specialized oscillator circuits capable of providing very stable and low phase noise signal is widely established. Among the transistor based high frequency oscillators, dielectric resonator oscillators are in limelight due to their higher stability and superior phase noise performance. This paper describes the design and development of a mechanically tunable dielectric resonator oscillator operable with a single dc supply. An ultra-low noise pHEMT is used in the oscillator core and a dielectric resonator puck from a commercial satellite television LNBF is used as high-Q tuning element.
{"title":"A free running dielectric resonator oscillator at 9.6 GHz","authors":"M. Yousaf, M. Ahmad","doi":"10.1109/IBCAST.2013.6512177","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512177","url":null,"abstract":"Oscillator is an integral and vital part of any RF/Microwave communication system. With an ever increasing demand of sophisticated applications in communication domain, the need for specialized oscillator circuits capable of providing very stable and low phase noise signal is widely established. Among the transistor based high frequency oscillators, dielectric resonator oscillators are in limelight due to their higher stability and superior phase noise performance. This paper describes the design and development of a mechanically tunable dielectric resonator oscillator operable with a single dc supply. An ultra-low noise pHEMT is used in the oscillator core and a dielectric resonator puck from a commercial satellite television LNBF is used as high-Q tuning element.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133580435","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 : 2013-05-02DOI: 10.1109/IBCAST.2013.6512129
N. Ullah, Shaoping Wang
This paper proposes higher order error dynamics based back stepping controller design to compensate extra torque disturbance of electrical load simulator (ELS). Lugre friction model based observer is used to compensate nonlinear friction. ELS system and friction modeling error as well as uncertain parameters may lead to tracking errors. Using adaptive back stepping control techniques, transient response is guaranteed at the cost of chattering in control signal which may affect the control performance as well as adaptive loops used to estimate the uncertain parameters. A higher order error dynamics based back stepping torque controller is derived from the parametric equation of ELS and its stability is proved using Lyapunov method. The validity of proposed controller is verified using computer simulations.
{"title":"Higher order error dynamics based backstepping controller design for electrical load simulator","authors":"N. Ullah, Shaoping Wang","doi":"10.1109/IBCAST.2013.6512129","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512129","url":null,"abstract":"This paper proposes higher order error dynamics based back stepping controller design to compensate extra torque disturbance of electrical load simulator (ELS). Lugre friction model based observer is used to compensate nonlinear friction. ELS system and friction modeling error as well as uncertain parameters may lead to tracking errors. Using adaptive back stepping control techniques, transient response is guaranteed at the cost of chattering in control signal which may affect the control performance as well as adaptive loops used to estimate the uncertain parameters. A higher order error dynamics based back stepping torque controller is derived from the parametric equation of ELS and its stability is proved using Lyapunov method. The validity of proposed controller is verified using computer simulations.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"66 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134093959","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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