Synchronization of the chaotic systems has attracted much attention in recent years due to its vital applications in secured communication systems. In this paper, an implementation and comparative analysis of two different control approaches for synchronization between two identical four-dimensional hyperchaotic systems is presented. The two control approaches are the Adaptive nonlinear controller and the linear optimal quadratic regulator LQR. To demonstrate the effectiveness of each controller, the numerical simulation is presented using Matlab/Simulink and the control law is derived. The performance of the proposed controllers is compared based on four factors; response time, squared error integration, energy applied from the controller, and cost function. To measure the robustness of the control approaches, the performance factors are compared when there is a change in system parameters and a variation in the initial conditions. Then the proposed synchronization methods are implemented on the FPGA platform to demonstrate the utilized resources on Field Programmable Gate Array (FPGA) hardware platform and the operation speed. Finally, to generalize the results of the comparison, the study is implemented for the synchronization of another secured communication system consisting of two identical three-dimensional chaotic. The experimental results show that the LQR method is more effective than the Adaptive controller based on the performance factors we propose. Moreover, the LQR is much simpler to implement on hardware and requires fewer resources on the FPGA.
An AC to DC voltage rectifier and its respective regulator were designed and integrated on a 0.25μm CMOS process. Its input impedance was measured along with the regulated DC output. Input impedance of a series of rectangular coil microstrip antenna on FR4 PCB with outer dimension of 78mm x 41mm was measured. The positive reactance of the antenna was matched at resonance with negative reactance of the integrated rectifier and regulator with addition of external capacitor. Relationship between incidental electromagnetic field in A/m at the coil microstrip antenna all the way to the rectified DC voltage at the output of the regulator is presented. In the context of wireless power transfer, this work focuses on the remote unit that absorbs electromagnetic field generated by another system and converts the energy into DC supply voltage for remote device