Simulation of three mutually coupled oscillators

In a practical multipurpose high frequency circuit, different oscillators are not completely isolated from each other. Instead, they interact with the environment, or with other oscillator. The interference between different oscillators may lead to generation of undesired signals. Therefore, the effect of oscillators on each other must be considered in the circuit design. As oscillators have nonlinear behavior, simulation of some of them which are coupled to each other needs more attention. In this report we present a mathematical model for three mutually coupled voltage controlled oscillators and solve it by a numerical method. The approach is illustrated by numerical experiments on realistic designs

Text steganography in color image using one LSB method along with histogram clustering

There have been presented several methods of steganography in image. A lot of these methods of embedding have been used at Least Significant Bit (LSB) positions of each pixel. In the proposed method in this article, using the histogram packaging and specifying is the most proper package for hiding text. The most important specification in this method is the little discrepancies in the histogram

Simulation of three mutually coupled oscillators

In a practical multipurpose high frequency circuit, different oscillators are not completely isolated from each other. Instead, they interact with the environment, or with other oscillator. The interference between different oscillators may lead to generation of undesired signals. Therefore, the effect of oscillators on each other must be considered in the circuit design. As oscillators have nonlinear behavior, simulation of some of them which are coupled to each other needs more attention. In this report we present a mathematical model for three mutually coupled voltage controlled oscillators and solve it by a numerical method. The approach is illustrated by numerical experiments on realistic designs

A dual band E-CRLH frequency multiplier with two multiplication factors

A dual-band microstrip distributed multiplier with two multiplication factors based on the extended composite right- and left-handed (E-CRLH) transmission lines (TLs) is presented. Dual-band operation for distributed multiplier is achieved by three cells, and each cell consists of a transistor, microstrip TL and E-CRLH transmission line. The distributed multiplier exhibits two multiplication factors in two different frequencies: one multiplication factor in reverse direction and the other multiplication factor in forward direction. The excellent agreement between the proposed technique and measurement results confirms the accuracy and efficiency of the method

LOD-FDTD method for physical simulation of semiconductor devices

This paper describes a locally one-dimensional finite-difference time domain method for the two-dimensional time-dependent simulation of semiconductor devices. This approach leads to significant reduction of the semiconductor simulation time. We can reach over 80% reduction in the simulation time by using this technique while maintaining the same degree of accuracy achieved using the conventional approach. As the first step in the performance investigation, we use the electrons flow equations in the absence of holes and recombination in this paper

Locally one-dimensional finite-difference time-domain scheme for the full-wave semiconductor device analysis

The application of an unconditionally stable locally one-dimensional finite-difference time-domain (LOD-FDTD) method for the full-wave simulation of semiconductor devices is described. The model consists of the electron equations for semiconductor devices in conjunction with Maxwell??s equations for electromagnetic effects. Therefore the behaviour of an active device at high frequencies is described by considering the distributed effects, propagation delays, electron transmit time, parasitic elements and discontinuity effects. The LOD-FDTD method allows a larger Courant??Friedrich??Lewy number (CFLN) as long as the dispersion error remains in the acceptable range. Hence, it can lead to a significant time reduction in the very time consuming full-wave simulation. Numerical results show the efficiency of the presented approach

LOD-FDTD method for physical simulation of semiconductor devices

This paper describes a locally one-dimensional finite-difference time domain method for the two-dimensional time-dependent simulation of semiconductor devices. This approach leads to significant reduction of the semiconductor simulation time. We can reach over 80% reduction in the simulation time by using this technique while maintaining the same degree of accuracy achieved using the conventional approach. As the first step in the performance investigation, we use the electrons flow equations in the absence of holes and recombination in this paper