We theoretically study domain wall oscillations upon the injection of a dc current through a geometrically constrained wire with perpendicular magnetic anisotropy. The frequency spectrum of the oscillation can be tuned by the injected current density and additionally by the application of an external magnetic field. Our analytical calculations are supported by micromagnetic simulations based on...

In this paper, we present our progress toward designing a “smart” high-peak power microwave (HPM) tube. We use iterative learning-control (ILC) methodologies in order to control a repetitively pulsed high-power backward-wave oscillator (BWO). The learning-control algorithm is used to drive the error between the actual output and its desired value to zero. The desired output may be a given power...

Abstract: In this paper, CMOS digitally controlled oscillator (DCO) design is analyzed for 4-16 bits. The CMOS DCO is designed based on a ring oscillator. Simulations of the analyzed DCO using 250nm CMOS technology achieve controllable different frequency range with a wide linearity. A 4-bit digitally controlled CMOS oscillator (DCO) design is best by adjusting the width of p-MOS and n-MOS devi...

We demonstrate how to construct and operate a simple and affordable apparatus for producing coherent effects in atomic vapor and for investigating their applications in time-keeping and magnetometery. The apparatus consists of a vertical cavity surface emitting diode laser directly current-modulated using a tunable microwave oscillator to produce multiple optical fields needed for the observati...

This paper describes an approach to model the transient and steady state behavior of differential microwave oscillators at the system level. Furthermore, phase noise characteristics can be emulated by the resulting models. The mathematical structure consist of a set of algebraic and differential equations that are solved by a VHDL-AMS interpreter. The nonlinearity occurring in the oscillator is...

In the light of some recent hypotheses suggesting plausible unification of thermostatistics where Fermi-Dirac, Bose-Einstein and Tsallis statistics become its special subsets, we consider further plausible extension to include non-integer Hausdorff dimension, which becomes realization of fractal entropy concept. In the subsequent section, we also discuss plausible extension of this unified stat...

Maxwell’s multipoles are a natural geometric characterisation of real functions on the sphere (with fixed l). The correlations between multipoles for gaussian random functions are calculated, by mapping the spherical functions to random polynomials. In the limit of high l, the 2-point function tends to a form previously derived by Hannay in the analogous problem for the Majorana sphere. The app...

Goodness-of-Fit tests, including Smooth ones, are introduced and applied to detect non-Gaussianity in Cosmic Microwave Background simulations. We study the power of three different tests: the Shapiro-Francia test (1972), the uncategorised smooth test developed by Rayner and Best(1990) and the Neyman’s Smooth Goodness-of-fit test for composite hypotheses (Thomas & Pierce 1979). The Smooth Goodne...

The variation of the perturbative 3-curvature parameter, ζ, is investigated in the period of reheating after inflation. The two-field model used has the inflaton, with an extra scalar field coupled to it, and non-linear effects of both fields are included as well as a slow decay mechanism into the hydrodynamic fluid of the radiation era. Changes in ζ occur and persist into the succeeding cosmic...

Quasi-optical power combining techniques have been developed to address fundamental limitations in solid-state devices and circuits. These techniques have been applied to oscillators, amplifiers, frequencyconversion components, and control circuits. This paper surveys progress in the development of quasi-optical array systems operating in the microwave and millimeterwave regime, focusing primar...