Implementation of High Performance Microstepping Driver Using FPGA with the Aim of Realizing Accurate Control on a Linear Motion System

This paper presents an FPGA-based microstepping driver which drives a linear motion system with a smooth and precise way. Proposed driver built on a Spartan3 FPGA (XC3S400 core) development board from Xilinx. Implementation of driver realized by an FPGA and using Verilog hardware description language in the Xilinx ISE environment. The driver’s control behavior can be adapted just by altering Verilog scripts. In addition, a linear motion system developed (with 4 mm movement per motor revolution) and coupled it to the stepper motor. The performance of the driver is tested by measuring the distance traveled on linear motion system. The experimental results verified using hardware-in-loop Matlab and Xilinx cosimulation method. This driver accomplishes a firm and accurate control and is responsive

A Monte-Carlo/FDTD Study of High-Efficiency Optical Antennas for LED-Based Visible Light Communication

In high-speed wireless communication, visible light communication is considered an emerging and cutting-edge technology. A light-emitting diode can serve both as an illumination source in an environment and as a data transmitter. Nevertheless, plenty of complications stand in the way of developing VLC technology, including the low response time of waveguides and detectors and the field of view dependence of such devices. To cover those challenges, one approach is to develop a superior optical antenna that does not have a low response time related to phosphorescence materials and should also support concentrating light from the surroundings with a wide field of view. This research paper presents an optimized cylindrical optical antenna with benefits, such as affordable cost, fast response time due to high-efficient nanomaterials, and a wide field of view (FOV). The proposed structure avoids the need for intricate tracking systems and active pointing to the source, but it can also be integrated into portable devices. For the analysis of nanomaterials’ characteristics, finite difference time domain simulations are used, and Monte-Carlo raytracing is used to study the proposed optical antenna. It was found that the antenna’s optical efficiency varies from 1 to 29% depending on the size and the number of nanomaterials inside. Compared to other works, this paper shows higher efficiencies and wider FOV

High-Resolution Color Transparent Display Using Superimposed Quantum Dots

In this paper, a high-resolution full-color transparent monitor is designed and fabricated using the synthesized quantum dots for the first time. For this purpose, about 100 compounds that had the potential to emit blue, green, and red lights were selected, and simulation was performed using the discrete dipole approximation (DDA) method, in which the shell layer was selected to be SiO2 or TiO2 in the first step. Among the simulated compounds with SiO2 or TiO2 shells, Se/SiO2 and BTiO3/SiO2 were selected as blue light emitters with high intensity and narrow bandwidth. Accordingly, CdSe/SiO2 nanoparticles were selected as green light emitters and Au/TiO2 for the red light. As the surface of the nanoparticles in their optical properties is important, reactivation of the nanoparticles’ surface is required to reach the high-intensity peak and resolution. To this end, in the second step, the surface of Se and CdSe nanoparticles reacted with ethanolamine, which can make a strong bond with cadmium atoms. The band structure and optical properties were obtained by the density functional theory (DFT) method. The Se/Ethanolamine and CdSe/Ethanolamine were experimentally synthesized to evaluate the theoretical results, and their optical properties were measured. To fabricate a transparent monitor, Se/Ethanolamine, CdSe/SiO2, and Au/TiO2 nanoparticles were dispersed in polyvinyl alcohol (PVA) solved in water and deposited on the glass by the doctor blading technique. Finally, high-resolution videos and images were displayed on the fabricated monitor