Stochastic analysis for one dimensional photonic crystals
Tolerance variations of the design parameters of the photonic crystals due to fabrication processes have a strong effect on the performance of the photonic crystals and their operating wavelengths. In this work, the uncertainties of the design parameters of one-dimensional photonic crystals (1D-PCs) and their impacts on the PCs optical properties and the operating performance are investigated. The effects of these uncertainties for different tolerances are studied for both defect-free PCs and PCs with a defect air layer. The probability distribution function and the standard deviations of the
Circuit Theory and Applications
Realizations of fractional-order PID loop-shaping controller for mechatronic applications
A novel procedure for the realization of a fractional-order PID loop-shaping controller, suitable for precision control of mechatronic systems, is introduced in this work. Exploiting appropriate tools, the controller function is approximated as a whole, leading to a simple form of integer-order approximation, when compared to the case where each intermediate part of the PID transfer function is approximated. This leads to a direct implementation, composed of conventional active and passive elements. Simulation and experimental results, derived from the OrCAD PSpice simulator and a Field
Circuit Theory and Applications
Current-Mode Carry-Free Multiplier Design using a Memristor-Transistor Crossbar Architecture
Multipliers are a major energy and delay contributor in modern compute-intensive applications due to their complex logic architecture. As such, designing multipliers with reduced energy and faster speed has remained a thoroughgoing challenge. This paper presents a novel, carry-free multiplier, which is suitable for a new-generation of energy-constrained applications. The multiplier circuit consists of an array of memristor-transistor cells that can be selected (i.e., turned ON or OFF) using a combination of DC bias voltages based on the operand values. When a cell is selected it contributes to
Power-law compensator design for plants with uncertainties: Experimental verification
A power-law compensator scheme for achieving robust frequency compensation in control systems including plants with an uncertain pole, is introduced in this work. This is achieved through an appropriate selection of the compensator parameters, which guarantee that the Nyquist diagram of the open-loop system compensator-plant crosses a fixed point independent of the plant pole variations. The implementation of the fractional-order compensator is performed through the utilization of a curve-fitting-based technique and the derived rational integer-order transfer function is realized on a Field
Circuit Theory and Applications
On chip 0.5 V 2 GHz four-output quadrature-phase oscillator
In this paper, we present a quadrature-phase oscillator that can provide four output voltages while operating from a single 0.5 V supply. The oscillator is based on two cross-coupled modified differential pair cells and provides signals with a phase difference of ±180° or ±90° depending on the chosen output nodes. A test chip with an active area of 0.175 mm2 was designed and fabricated in a 65-nm CMOS process and its measurement results show a phase noise of −119.5 dBc/Hz at 1 MHz offset from a carrier frequency of 1.967 GHz while consuming 6.15mW. Finally, experimental results show a FoM of