This paper presents a linear controller for a multifrequency model of a pulse-widthmodulated Ćuk converter. The controller is based on an equivalent discrete-time version of the linearized multifrequency model and uses the continuous-time output over one switching period. Using this combination we determine the duty ratio at the beginning of every switching period. We discuss how this controlle...

In tagged magnetic resonance imaging of the human heart, diierent frequency patterns can be imposed and imaged as the heart moves. It is advantageous to use low-frequency patterns to improve both image acquisition time and the performance of gradient-based optical ow motion analysis methods. This paper explores the eeects of three factors | image preeltering, multireso-lution optical ow, and mu...

in this paper, a novel directional super wide band micro strip antenna based on a simple and new geometry has been proposed. the antenna exhibits the widest bandwidth ever reported to the authors’ knowledge from 50 ghz to 200 ghz. its radiation pattern is approximately steady in the frequency ranges of 50 ghz to 200 ghz. the antenna consists of a club-like radiating patch, a combination of thre...

This work presents a design and experimental validation of compact ultrawideband (UWB) bowtie antenna balanced-to-unbalanced (balun) circuit for medical microwave imaging (MWI) applications working in the frequency band 1–6 GHz. The UWB balun is perpendicularly attached to planar arms, whose dimensions were miniaturized by rounding edges. reflection coefficient was lower than −12 dB tissues wit...

INTRODUCTION  The use of conventional tympanometry is not sufficiently sensitive to detect all cases of middle ear changes, and this hinders accurate diagnosis. OBJECTIVE  To characterize acoustic immittance measures of infants from 0 to 3 months of age using multifrequency tympanometry in a prospective study. METHOD  54 infants from 0 to 3 months of age were evaluated. The inclusion criter...

BACKGROUND AND PURPOSE The goal of this study was to assess the first multifrequency transcranial Doppler system specially developed for online automatic detection of cerebral microemboli. METHODS The multifrequency Doppler instrumentation insonates simultaneously with 2.0- and 2.5-MHz frequencies. The detection threshold for embolus detection used in this study was a relative Doppler energy ...

a newly designed printed slot antenna is presented that incorporates variable two band-notched functions for ultra-wideband (uwb) applications. the two band notches of this coplanar waveguide (cpw) fed antenna are achieved by an m-shaped slot (mss) embedded in the radiating element and a c-shaped strip(css) close to ground plane, therefore two very narrow rejected properties in the wireless loc...