Although chaotic signals are considered to have great potential applications in radar and communication engineering, their broadband spectrum makes it difficult to design an applicable amplifier or an attenuator for a...Although chaotic signals are considered to have great potential applications in radar and communication engineering, their broadband spectrum makes it difficult to design an applicable amplifier or an attenuator for amplitude conditioning. Moreover, the transformation between a unipolar signal and a bipolar signal is often required. In this paper, a more intelligent hardware implementation based on field programmable analog array (FPAA) is constructed for chaotic systems with complete amplitude control. Firstly, two chaotic systems with complete amplitude control are introduced, one of which has the property of offset boosting with total amplitude control, while the other has offset boosting and a parameter for partial control. Both cases can achieve complete amplitude control including amplitude rescaling and offset boosting. Secondly, linear synchronization is established based on the special structure of chaotic system. Finally, experimental circuits are constructed on an FPAA where the predicted amplitude control is realized through only two independent configurable analog module (CAM) gain values.展开更多
The variable structure control (VSC) theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a s...The variable structure control (VSC) theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a saturation function is adopted. The proposed VSC approach is fairly robust to load disturbance and system parameter variation. Since the distortion. including phase lag and amplitude attenuation occurs in the system sinusoid response, the amplitude and phase control (APC) algorithm, based on Adaline neural network and using LMS algorithm, is developed for distortion cancellation. The APC controller is simple and can on-line adjust, thus it gives accurate tracking.展开更多
By introducing a discrete memristor and periodic sinusoidal functions,a two-dimensional map with coexisting chaos and hyperchaos is constructed.Various coexisting chaotic and hyperchaotic attractors under different Ly...By introducing a discrete memristor and periodic sinusoidal functions,a two-dimensional map with coexisting chaos and hyperchaos is constructed.Various coexisting chaotic and hyperchaotic attractors under different Lyapunov exponents are firstly found in this discrete map,along with which other regimes of coexistence such as coexisting chaos,quasiperiodic oscillation,and discrete periodic points are also captured.The hyperchaotic attractors can be flexibly controlled to be unipolar or bipolar by newly embedded constants meanwhile the amplitude can also be controlled in combination with those coexisting attractors.Based on the nonlinear auto-regressive model with exogenous inputs(NARX)for neural network,the dynamics of the memristive map is well predicted,which provides a potential passage in artificial intelligencebased applications.展开更多
An N-stage three-waveguide system is proposed to improve the robustness and the fidelity of the resonant tunneling passage.The analytic solutions to the tunneling dynamics at the output are derived.When the number of ...An N-stage three-waveguide system is proposed to improve the robustness and the fidelity of the resonant tunneling passage.The analytic solutions to the tunneling dynamics at the output are derived.When the number of subsystems increases,tunneling efficiency approaches to 100%in a large range and resonant tunneling is robust against variations in the phase mismatch and peak tunneling rate.展开更多
New techniques for controlling the amplitudes of two orthogonal linearly polarized light are presented. One is based on adjusting the DC voltage into a Mach–Zehnder modulator(MZM) to alter the amplitude of the ligh...New techniques for controlling the amplitudes of two orthogonal linearly polarized light are presented. One is based on adjusting the DC voltage into a Mach–Zehnder modulator(MZM) to alter the amplitude of the light traveling on the slow axis of a fiber into the modulator with little changes in the fast-axis light amplitude.Another is based on adjusting the input DC voltages of a dual-polarization MZM operating in the reverse direction, which enables independent control of the two input orthogonal linearly polarized light amplitudes.Experimental results demonstrate that more than 30 dB difference in slow-and fast-axis light power can be obtained by controlling an MZM input DC voltage, and over 24 dB independent power adjustment for light traveling on the slow and fast axes into a dual-polarization MZM.展开更多
We investigate the optical bistabiiity (OB) in a duplicated two-level system contained in a ring cavity. The atoms are driven by two orthogonally polarized fields with a relative phase. The OB behavior of such a sys...We investigate the optical bistabiiity (OB) in a duplicated two-level system contained in a ring cavity. The atoms are driven by two orthogonally polarized fields with a relative phase. The OB behavior of such a system can be controlled by the amplitude and the relative phase of the coupling field, and it is possible to switch between bistabilitv and multistability by adjusting the relative phase.展开更多
A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed ...A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed manner is improved to resolve the unbalance problem under amplitude and phase control. In order to validate the algorithm correct and effective, an actual engineering application example is investigated. The beam synthesis results of 1.0~4.5 times broadening under the phase only control and the amplitude and phase control using improved PMA are given. The results show that the beam directivity, the beam broadening, and the side-lobe level requirements were met. It is demonstrated that the improved PMA was effective and feasible for SAR application.展开更多
基金Project supported by the Startup Foundation for Introducing Talent of Nanjing University of Information Science&Technology,China(Grant No.2016205)the Natural Science Foundation of the Jiangsu Higher Education Institutions of Jiangsu Province,China(Grant No.16KJB120004)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Natural Science Foundation of Hebei Province,China(Grant No.A2015108010)
文摘Although chaotic signals are considered to have great potential applications in radar and communication engineering, their broadband spectrum makes it difficult to design an applicable amplifier or an attenuator for amplitude conditioning. Moreover, the transformation between a unipolar signal and a bipolar signal is often required. In this paper, a more intelligent hardware implementation based on field programmable analog array (FPAA) is constructed for chaotic systems with complete amplitude control. Firstly, two chaotic systems with complete amplitude control are introduced, one of which has the property of offset boosting with total amplitude control, while the other has offset boosting and a parameter for partial control. Both cases can achieve complete amplitude control including amplitude rescaling and offset boosting. Secondly, linear synchronization is established based on the special structure of chaotic system. Finally, experimental circuits are constructed on an FPAA where the predicted amplitude control is realized through only two independent configurable analog module (CAM) gain values.
文摘The variable structure control (VSC) theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a saturation function is adopted. The proposed VSC approach is fairly robust to load disturbance and system parameter variation. Since the distortion. including phase lag and amplitude attenuation occurs in the system sinusoid response, the amplitude and phase control (APC) algorithm, based on Adaline neural network and using LMS algorithm, is developed for distortion cancellation. The APC controller is simple and can on-line adjust, thus it gives accurate tracking.
基金Project supported by the National Natural Science Foundation of China(Grant No.61871230)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20181410)the Postgraduate Research and Practice Innovation Project of Jiangsu Province,China(Grant No.SJCX210350).
文摘By introducing a discrete memristor and periodic sinusoidal functions,a two-dimensional map with coexisting chaos and hyperchaos is constructed.Various coexisting chaotic and hyperchaotic attractors under different Lyapunov exponents are firstly found in this discrete map,along with which other regimes of coexistence such as coexisting chaos,quasiperiodic oscillation,and discrete periodic points are also captured.The hyperchaotic attractors can be flexibly controlled to be unipolar or bipolar by newly embedded constants meanwhile the amplitude can also be controlled in combination with those coexisting attractors.Based on the nonlinear auto-regressive model with exogenous inputs(NARX)for neural network,the dynamics of the memristive map is well predicted,which provides a potential passage in artificial intelligencebased applications.
基金supported by the Natural Science Basic Research Plan in Shaanxi Province,China(Grant No.2018JM6064)。
文摘An N-stage three-waveguide system is proposed to improve the robustness and the fidelity of the resonant tunneling passage.The analytic solutions to the tunneling dynamics at the output are derived.When the number of subsystems increases,tunneling efficiency approaches to 100%in a large range and resonant tunneling is robust against variations in the phase mismatch and peak tunneling rate.
文摘New techniques for controlling the amplitudes of two orthogonal linearly polarized light are presented. One is based on adjusting the DC voltage into a Mach–Zehnder modulator(MZM) to alter the amplitude of the light traveling on the slow axis of a fiber into the modulator with little changes in the fast-axis light amplitude.Another is based on adjusting the input DC voltages of a dual-polarization MZM operating in the reverse direction, which enables independent control of the two input orthogonal linearly polarized light amplitudes.Experimental results demonstrate that more than 30 dB difference in slow-and fast-axis light power can be obtained by controlling an MZM input DC voltage, and over 24 dB independent power adjustment for light traveling on the slow and fast axes into a dual-polarization MZM.
基金supported by the National Natural Science Foundation of China(Nos.61108006 and 11104221)the Scientific Research Program Funded by Shaanxi Provincial Education Department(No.11JK0529)+2 种基金the Natural Science Basis Research Plan in Shaanxi Province of China(No.2010JQ1002)the Doctoral Program Foundation of Institutions of Higher Education of China(No.20106101120020)the support from the Science Foundation of Northwest University(No.10NW14)
文摘We investigate the optical bistabiiity (OB) in a duplicated two-level system contained in a ring cavity. The atoms are driven by two orthogonally polarized fields with a relative phase. The OB behavior of such a system can be controlled by the amplitude and the relative phase of the coupling field, and it is possible to switch between bistabilitv and multistability by adjusting the relative phase.
文摘A new beam broadening synthesis technique for Synthetic Aperture Radar(SAR) antenna array, namely Projection Matrix Algorithm(PMA) is presented. The theory of PMA is introduced firstly, and then the iterative renewed manner is improved to resolve the unbalance problem under amplitude and phase control. In order to validate the algorithm correct and effective, an actual engineering application example is investigated. The beam synthesis results of 1.0~4.5 times broadening under the phase only control and the amplitude and phase control using improved PMA are given. The results show that the beam directivity, the beam broadening, and the side-lobe level requirements were met. It is demonstrated that the improved PMA was effective and feasible for SAR application.