Pub Date : 2017-06-01DOI: 10.1109/NAECON.2017.8268756
Seyed Ata Raziei, Zhenhua Jiang
Hybrid actuators can provide better performances than hydraulic or electromechanical actuators alone; however, control of these hybrid systems is more challenging. This paper presents the application of model predictive control (MPC) on a hybrid actuator system to coordinate multiple control objectives. MPC has advantages over traditional controllers such as a PID in controlling non-linear multi-input, multi-output systems. MPC proactively updates the control inputs in a specific time interval by observing the current state of the system, predicting the future behavior, and solving an optimization problem repeatedly with consideration of pre-defined control objectives. In this paper, a high-fidelity dynamic model of the hybrid actuator system will be developed and a simplified, reduced-order model will be derived for use in the MPC formulation process. The detailed process of designing an MPC controller, which may consist of mathematical formulation of an optimization problem and numerical methods to find the optimal solution, will be discussed in detail. Simulation results will be presented to compare the performances of the MPC with PID controllers, and the effects of different controller parameters on the system performances will be discussed.
{"title":"Dynamic modeling and nonlinear model predictive control of hybrid actuator systems","authors":"Seyed Ata Raziei, Zhenhua Jiang","doi":"10.1109/NAECON.2017.8268756","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268756","url":null,"abstract":"Hybrid actuators can provide better performances than hydraulic or electromechanical actuators alone; however, control of these hybrid systems is more challenging. This paper presents the application of model predictive control (MPC) on a hybrid actuator system to coordinate multiple control objectives. MPC has advantages over traditional controllers such as a PID in controlling non-linear multi-input, multi-output systems. MPC proactively updates the control inputs in a specific time interval by observing the current state of the system, predicting the future behavior, and solving an optimization problem repeatedly with consideration of pre-defined control objectives. In this paper, a high-fidelity dynamic model of the hybrid actuator system will be developed and a simplified, reduced-order model will be derived for use in the MPC formulation process. The detailed process of designing an MPC controller, which may consist of mathematical formulation of an optimization problem and numerical methods to find the optimal solution, will be discussed in detail. Simulation results will be presented to compare the performances of the MPC with PID controllers, and the effects of different controller parameters on the system performances will be discussed.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121160022","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 : 2017-06-01DOI: 10.1109/NAECON.2017.8268760
Joshua M. Kaster, James Patrick, H S Clouse
In the revolutionary field of deep learning many difficult computer vision challenges of today are being impressively overcome by the application of these cutting edge technologies. The challenge of detecting vehicular objects from aerial imagery is a long-standing interest in computer vision. Performing this accurately in real-time while utilizing the payload bay of a small unmanned aerial system (SUAS) is even more desirable and challenging. In this work, these challenges are successfully surmounted with the use of Faster R-CNN [1], a highly cultivated aerial image dataset, supercomputers, and a dedicated team of SUAS experts. By first training Faster R-CNN on a customized dataset of electro-optical (EO) annotated aerial imagery then empirically testing on supercomputers across hundreds of hyperparameters, the resulting optimized network was successfully integrated into established SUAS operations. This combination of cutting edge technologies lead to strong performance while requiring a fraction of the development time and meeting strict in-flight SWaP requirements.
{"title":"Convolutional neural networks on small unmanned aerial systems","authors":"Joshua M. Kaster, James Patrick, H S Clouse","doi":"10.1109/NAECON.2017.8268760","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268760","url":null,"abstract":"In the revolutionary field of deep learning many difficult computer vision challenges of today are being impressively overcome by the application of these cutting edge technologies. The challenge of detecting vehicular objects from aerial imagery is a long-standing interest in computer vision. Performing this accurately in real-time while utilizing the payload bay of a small unmanned aerial system (SUAS) is even more desirable and challenging. In this work, these challenges are successfully surmounted with the use of Faster R-CNN [1], a highly cultivated aerial image dataset, supercomputers, and a dedicated team of SUAS experts. By first training Faster R-CNN on a customized dataset of electro-optical (EO) annotated aerial imagery then empirically testing on supercomputers across hundreds of hyperparameters, the resulting optimized network was successfully integrated into established SUAS operations. This combination of cutting edge technologies lead to strong performance while requiring a fraction of the development time and meeting strict in-flight SWaP requirements.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116085925","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 : 2017-06-01DOI: 10.1109/NAECON.2017.8268775
Esmail M. M. Abuhdima, R. Penno
Simulation of the rotation and translation of a very good conducting cylinder upon the backscattered field of an incident plane wave (H-wave) is investigated using the Franklin transformation and the Lorentz transformation. It is seen that both phase and magnitude of the backscattered field are affected during the movement (rotation and translation) of the very good conducting cylinder. FEKO is used to generate static backscattered field data of the complex object, and then this data is inserted into the proposed model to demonstrate simulation of rotation and translation. Also, this result is compared with the analytical method.
{"title":"A new model for simulation of scattered EM fields from a conducting cylinder in rotation and translation using static data","authors":"Esmail M. M. Abuhdima, R. Penno","doi":"10.1109/NAECON.2017.8268775","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268775","url":null,"abstract":"Simulation of the rotation and translation of a very good conducting cylinder upon the backscattered field of an incident plane wave (H-wave) is investigated using the Franklin transformation and the Lorentz transformation. It is seen that both phase and magnitude of the backscattered field are affected during the movement (rotation and translation) of the very good conducting cylinder. FEKO is used to generate static backscattered field data of the complex object, and then this data is inserted into the proposed model to demonstrate simulation of rotation and translation. Also, this result is compared with the analytical method.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114040316","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 : 2017-06-01DOI: 10.1109/NAECON.2017.8268788
Abdulhakim Daluom, M. Wicks, H. Abdelbagi, Abdunaser Abdusamad, Muftah Akroush, Turki M. Alanazi
In this paper, we present a unique Ground Penetrating Radar (GPR) technique currently under development to image deeply buried targets over relatively small areas of regard. This GPR computes the optimal sensor geometry for a given bistatic and multi-static radar distribution of transmitters and receivers operating in the microwave band of frequencies. There are M receivers, and they can be arranged arbitrarily. In addition to that, we have N transmitters that we can also arrange in the same way. Each receiver can process all frequencies from the multiple transmitters. The transmitters are deployed above ground, while the receivers are in the space between the surface of the ground and the multitude of transmitters. Radio frequency (RF) tomography is developed using Green's functions and Maxwell's equations to develop an algorithm for imaging underground targets. The targets are assumed to be inside a region of interest (ROI). The design includes different transmitter (Tx) and receiver (Rx) geometries, such as concentric circles and concentric squares. Based on these different geometries we determine which distribution is best for imaging depths of shallow buried targets. Also, the development of the optimal sensor geometry is investigated in order to provide the best configurations and increase overall tomographic imagery. Simulation results show excellent performance in the absence of significant unknown disturbances.
{"title":"Optimal sensor geometry for tomographic below ground imaging of objects in a region of interest","authors":"Abdulhakim Daluom, M. Wicks, H. Abdelbagi, Abdunaser Abdusamad, Muftah Akroush, Turki M. Alanazi","doi":"10.1109/NAECON.2017.8268788","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268788","url":null,"abstract":"In this paper, we present a unique Ground Penetrating Radar (GPR) technique currently under development to image deeply buried targets over relatively small areas of regard. This GPR computes the optimal sensor geometry for a given bistatic and multi-static radar distribution of transmitters and receivers operating in the microwave band of frequencies. There are M receivers, and they can be arranged arbitrarily. In addition to that, we have N transmitters that we can also arrange in the same way. Each receiver can process all frequencies from the multiple transmitters. The transmitters are deployed above ground, while the receivers are in the space between the surface of the ground and the multitude of transmitters. Radio frequency (RF) tomography is developed using Green's functions and Maxwell's equations to develop an algorithm for imaging underground targets. The targets are assumed to be inside a region of interest (ROI). The design includes different transmitter (Tx) and receiver (Rx) geometries, such as concentric circles and concentric squares. Based on these different geometries we determine which distribution is best for imaging depths of shallow buried targets. Also, the development of the optimal sensor geometry is investigated in order to provide the best configurations and increase overall tomographic imagery. Simulation results show excellent performance in the absence of significant unknown disturbances.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125331839","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}
In this paper, we present a differential flatness based hybrid flight controller for the quadcopter UAV. The combination of conventional PID based controller with the full state feedback based LQR controller results in the proposed hybrid controller. The performance of the resulting controller is further enhanced by using differential flatness based feedforward control. The UAV with a hybrid flight controller is considered as the balance between stability and maneuverability, which makes it suitable for complex trajectory following applications. The dynamic model and the flight controller has been verified by means of numerical simulations for flight conditions involving complex maneuvers.
{"title":"Differential flatness based hybrid PID/LQR flight controller for complex trajectory tracking in quadcopter UAVs","authors":"Rumit Kumar, Matthew Dechering, Abhishek Pai, Austin Ottaway, Mohammadreza Radmanesh, Manish Kumar","doi":"10.1109/NAECON.2017.8268755","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268755","url":null,"abstract":"In this paper, we present a differential flatness based hybrid flight controller for the quadcopter UAV. The combination of conventional PID based controller with the full state feedback based LQR controller results in the proposed hybrid controller. The performance of the resulting controller is further enhanced by using differential flatness based feedforward control. The UAV with a hybrid flight controller is considered as the balance between stability and maneuverability, which makes it suitable for complex trajectory following applications. The dynamic model and the flight controller has been verified by means of numerical simulations for flight conditions involving complex maneuvers.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127687328","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 : 2017-06-01DOI: 10.1109/NAECON.2017.8268771
D. Landgren, Kevin R. Cook, D. Dykes, J. Perez, P. R. Bowden, K. Allen
In this article an ultra-wideband (UWB), millimeter wave (mmWave) fragmented antenna with a single feed point is presented. The conductor region of the antenna aperture is approximately 0.5 mm by 2.0 mm or 0.07 λ × 0.25 λ at the shortest wavelength of operation. The antenna was fabricated on a 1.97 mm thick Rogers 5880LZ substrate using standard etching processes. Prior to fabrication, the antenna design was simulated across two different full-wave electromagnetic (EM) solvers, HFSS and GTRI's in-house finite-difference time-domain (FDTD) code; the two codes were in close agreement. The antenna prototype was characterized for reflection coefficient, realized gain, and principle plane patterns. These measurements closely agree with EM predictions.
{"title":"A wideband mmWave antenna element with an unbalanced feed","authors":"D. Landgren, Kevin R. Cook, D. Dykes, J. Perez, P. R. Bowden, K. Allen","doi":"10.1109/NAECON.2017.8268771","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268771","url":null,"abstract":"In this article an ultra-wideband (UWB), millimeter wave (mmWave) fragmented antenna with a single feed point is presented. The conductor region of the antenna aperture is approximately 0.5 mm by 2.0 mm or 0.07 λ × 0.25 λ at the shortest wavelength of operation. The antenna was fabricated on a 1.97 mm thick Rogers 5880LZ substrate using standard etching processes. Prior to fabrication, the antenna design was simulated across two different full-wave electromagnetic (EM) solvers, HFSS and GTRI's in-house finite-difference time-domain (FDTD) code; the two codes were in close agreement. The antenna prototype was characterized for reflection coefficient, realized gain, and principle plane patterns. These measurements closely agree with EM predictions.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128078532","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 : 2017-06-01DOI: 10.1109/NAECON.2017.8268762
Zhenhua Jiang, Sayed Ata Raziei
This paper presents a novel method to finding the solution to a system of linear equations efficiently by using a reconfigurable hardware based real-time computational solver. The presented linear solver is to directly solve the system of linear equations through repetitively applying Gauss-Jordan elimination to each column of an augmented matrix in parallel on reconfigurable hardware, which can greatly accelerate the solution procedure. Backward substitution is not needed, so the computing latency can be further reduced. The main components of the hardware solver include parallel data processing modules, reusable memory blocks and flexible control logic units. By considering pivoting, this solver can avoid the potential problem of increasingly-large numbers after row operations. The salient feature is that the latency of this solver is really low through parallel processing, deep pipelining and flexible use of memory blocks. For instance, the total latency of this linear solver is controlled below 1000 clock cycles for a dense system of dimension 32. On a Xilinx Vertex 6 FPGA of 200MHz, which has a clock cycle of 5ns, the minimum latency can be as low as 5 microseconds. Applications of this hardware accelerated linear solver may include, but are not limited to, real-time least square estimation for sensor data, digital signal / video processing and real-time circuit simulation. It can also find wide applications in mathematical computing such as finding the inverse of a matrix, computing determinants or ranks of matrices, etc.
{"title":"An efficient FPGA-based direct linear solver","authors":"Zhenhua Jiang, Sayed Ata Raziei","doi":"10.1109/NAECON.2017.8268762","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268762","url":null,"abstract":"This paper presents a novel method to finding the solution to a system of linear equations efficiently by using a reconfigurable hardware based real-time computational solver. The presented linear solver is to directly solve the system of linear equations through repetitively applying Gauss-Jordan elimination to each column of an augmented matrix in parallel on reconfigurable hardware, which can greatly accelerate the solution procedure. Backward substitution is not needed, so the computing latency can be further reduced. The main components of the hardware solver include parallel data processing modules, reusable memory blocks and flexible control logic units. By considering pivoting, this solver can avoid the potential problem of increasingly-large numbers after row operations. The salient feature is that the latency of this solver is really low through parallel processing, deep pipelining and flexible use of memory blocks. For instance, the total latency of this linear solver is controlled below 1000 clock cycles for a dense system of dimension 32. On a Xilinx Vertex 6 FPGA of 200MHz, which has a clock cycle of 5ns, the minimum latency can be as low as 5 microseconds. Applications of this hardware accelerated linear solver may include, but are not limited to, real-time least square estimation for sensor data, digital signal / video processing and real-time circuit simulation. It can also find wide applications in mathematical computing such as finding the inverse of a matrix, computing determinants or ranks of matrices, etc.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124175538","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 : 2017-06-01DOI: 10.1109/NAECON.2017.8268757
Turki Alsuwian, R. Ordóñez, L. Jacobsen
Hypersonic vehicles are complex nonlinear systems with uncertain dynamics. This work presents a robust nonlinear adaptive (NA) control system for the operation of these vehicles at subsonic speeds. The complexity of the dynamic system is considered in the design, in order to address robustness issues. In this work, we only consider lateral dynamics with a fixed roll angle (five degree of freedom, or 5-DOF). These dynamics are divided into subsystems for aircraft speed, flight-path angle, and yaw angle. A robust NA control design is implemented to provide asymptotic tracking regulation of these output quantities. Adaptation is employed in this study because of its robustness properties. The stability analysis is performed based on a Lyapunov function for the feedback closed-loop system. Simulations of the design indicates that it successfully provides flight control.
{"title":"Nonlinear adaptive control for lateral dynamics with fixed roll angle of hypersonic vehicles at subsonic speeds","authors":"Turki Alsuwian, R. Ordóñez, L. Jacobsen","doi":"10.1109/NAECON.2017.8268757","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268757","url":null,"abstract":"Hypersonic vehicles are complex nonlinear systems with uncertain dynamics. This work presents a robust nonlinear adaptive (NA) control system for the operation of these vehicles at subsonic speeds. The complexity of the dynamic system is considered in the design, in order to address robustness issues. In this work, we only consider lateral dynamics with a fixed roll angle (five degree of freedom, or 5-DOF). These dynamics are divided into subsystems for aircraft speed, flight-path angle, and yaw angle. A robust NA control design is implemented to provide asymptotic tracking regulation of these output quantities. Adaptation is employed in this study because of its robustness properties. The stability analysis is performed based on a Lyapunov function for the feedback closed-loop system. Simulations of the design indicates that it successfully provides flight control.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132418677","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 : 2017-06-01DOI: 10.1109/NAECON.2017.8268748
C. Yakopcic, Nayim Rahman, Tanvir Atahary, T. Taha, Scott Douglass
Cognitive agents are typically utilized in autonomous systems for automated decision making. These systems interact at real time with their environment and are generally heavily power constrained. Thus, there is a strong need for a real time agent running on a low power platform. This paper examines how some of the components of a cognitive agent can be executed in memristor crossbar circuits capable of highly parallel instruction execution. The agent examined is the Cognitively Enhanced Complex Event Processing (CECEP) architecture. This is an autonomous decision support tool that reasons like humans and enables enhanced agent-based decision-making. It has applications in a large variety of domains including autonomous systems, operations research, intelligence analysis, and data mining. One of the most time consuming and key components of CECEP is the mining of knowledge from a repository described as a Cognitive Domain Ontology (CDO). We show that CDOs can be implemented using memristor crossbars using two different approaches. The first is a lookup table approach that is stored in a high density memristor matching circuit. The second in a multilayer perceptron implementation that uses an ex-situ memristor based neuromorphic system. In each case, the example CDOs are implemented successfully.
{"title":"Cognitive domain ontologies in a memristor crossbar architecture","authors":"C. Yakopcic, Nayim Rahman, Tanvir Atahary, T. Taha, Scott Douglass","doi":"10.1109/NAECON.2017.8268748","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268748","url":null,"abstract":"Cognitive agents are typically utilized in autonomous systems for automated decision making. These systems interact at real time with their environment and are generally heavily power constrained. Thus, there is a strong need for a real time agent running on a low power platform. This paper examines how some of the components of a cognitive agent can be executed in memristor crossbar circuits capable of highly parallel instruction execution. The agent examined is the Cognitively Enhanced Complex Event Processing (CECEP) architecture. This is an autonomous decision support tool that reasons like humans and enables enhanced agent-based decision-making. It has applications in a large variety of domains including autonomous systems, operations research, intelligence analysis, and data mining. One of the most time consuming and key components of CECEP is the mining of knowledge from a repository described as a Cognitive Domain Ontology (CDO). We show that CDOs can be implemented using memristor crossbars using two different approaches. The first is a lookup table approach that is stored in a high density memristor matching circuit. The second in a multilayer perceptron implementation that uses an ex-situ memristor based neuromorphic system. In each case, the example CDOs are implemented successfully.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116978799","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 : 2017-06-01DOI: 10.1109/NAECON.2017.8268797
W.-D. Zhang, A. Mingardi, E. R. B. Terahertz
In planar substrate-based wire grid polarizers, it has been found that high extinction ratio (∼60 dB) and low insertion loss (a few dB) can be achieved if the fill-factor (FF, ratio of metal strip width to period) exceeds 90%. In this research, we utilize these high FF wire-grid polarizers for a first implementation of polarimetric W-band radar.
{"title":"New high-extinction wire-grid polarizers for polarimetrie W-band radar","authors":"W.-D. Zhang, A. Mingardi, E. R. B. Terahertz","doi":"10.1109/NAECON.2017.8268797","DOIUrl":"https://doi.org/10.1109/NAECON.2017.8268797","url":null,"abstract":"In planar substrate-based wire grid polarizers, it has been found that high extinction ratio (∼60 dB) and low insertion loss (a few dB) can be achieved if the fill-factor (FF, ratio of metal strip width to period) exceeds 90%. In this research, we utilize these high FF wire-grid polarizers for a first implementation of polarimetric W-band radar.","PeriodicalId":306091,"journal":{"name":"2017 IEEE National Aerospace and Electronics Conference (NAECON)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131399161","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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