In this paper a resonant tunnelling quantum well infrared photodetector (RT-QWIP) is discussed. Each period of this photodetector structure comprises of a resonant tunnelling structure (AlAs/AlGaAs/AlAs) nearby a quantum well (AlGaAs/GaAs). In this photodetector, photocurrent is produced when an electron makes a transition from the ground state of the well to an excited state which is coupled t...

In this research, a new explanation and design crystal oscillator based on injection locking phenomenon is proposed. The crystal oscillator is viewed as a regular oscillator whereas is ac small input signal is its forced function. In this work, a crystal is considered to be a very small sinusoidal signal generator. To guarantee that the injection locking phenomenon is occurred the frequency of ...

We consider a radiation from a uniformly accelerating harmonic oscillator whose minimal coupling to the scalar field changes suddenly. The exact time evolutions of the quantum operators are given in terms of a classical solution of a forced harmonic oscillator. After the jumping of the coupling constant there occurs a fast absorption of energy into the oscillator, and then a slow emission follo...

Introduction A key circuit used in modern communication systems is the voltage controlled oscillator (VCO). The VCO's output is an AC waveform whose frequency is dependent upon the input voltage. In today's wireless communication systems, a greater maximum frequency range is required by VCOs. With respect to the digital phones that use these circuits, low power consumption, small size and low f...

We have studied the underlying algebraic structure of the anharmonic oscillator by using the variational perturbation theory. To the first order of the variational perturbation, the Hamiltonian is found to be factorized into a supersymmetric form in terms of the annihilation and creation operators, which satisfy a q-deformed algebra. This algebraic structure is used to construct all the eigenst...

in this work, time domain analysis is used to solve adler’s equation in order to obtain the required time, for an oscillator under external injection, reaching the steady-state condition. mathematical approach has been applied to fully describe the transient of frequency acquisition in injection-locked lc and ring oscillators considering their time-varying nature. then, the analysis is verified...

We generalize the previously considered cases of a harmonic oscillator subject to a random force (Brownian motion), or having random frequency, or random damping. We consider here a random mass which corresponds to an oscillator where the particles of the surrounding medium adhere to the oscillator for some (random) time after collision, thereby changing the oscillator mass. Such a model is app...

This paper examines an electronic oscillator forced by a pseudo-random noise signal. We give evidence of the existence of one or more random at-tractors for the system depending on noise amplitude and system parameters. These random attractors may appear to be random xed points or random chaotic attractors. In the latter case, we observe a form of intermittent synchronization of the response of...

David Terman Department of Mathematics The Ohio State University Columbus, Ohio 43210, USA [email protected] An novel class of locally excitatory, globally inhibitory oscillator networks is proposed. The model of each oscillator corresponds to a standard relaxation oscillator with two time scales. The network exhibits a mechanism of selective gating, whereby an oscillator jumping up to...