A local radio frequency (rf) shielding consisting of a Cu plate and an LC balun circuit has been developed for a compact magnetic resonance imaging (MRI) system with a 0.3 T permanent magnet. Performance of the local rf shielding was evaluated using an artificial external noise source irradiating a human subject whose hand was inserted into the rf coil of the MRI system. Power spectra of the rf...

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...

The RF MEMS technology has a great potential to replace conventional switching techniques and it can offer highly miniature switches and sensors with superior RF performance. The main principle of a RF MEMS based power senor is based on sensing the attractive electrostatic force between the signal line and a free standing electrode that is suspended at a small distance from the signal line. Key...

In this study, we investigate measurement of the magnetic permeability in a ferrite core at RF frequencies when bias current is superimposed on an RF signal with a view to adaptively controlling performance of RF transformers using ferrite cores. A measurement arrangement used comprises a short microstrip line (MSL) circuit including a coaxial conductor (CC) structure consisting of an electrica...

A simplified millimeter-wave (mm-wave) radio-over-fiber (RoF) system employing a combination of optical heterodyning in signal generation and radio frequency (RF) self-homodyning in data recovery process is proposed and demonstrated. Three variants of the system are considered in which two independent uncorrelated lasers with a frequency offset equal to the desired mm-wave carrier frequency are...

Background Late Gadolinium Enhancement (LGE) allows imaging of infarction and cardiomyopathies by measuring the accumulation of contrast agent within the myocardium. The shortened T1 relaxation time compared to healthy myocardium is imaged by an inversion recovery (IR) prepared segmented fast gradient echo sequence in which pathology and fat show as bright signal. The fat signal can lead to mis...

FISH probes are generally made out of BAC clones with genomic DNA containing a variable amount of repetitive DNA that will need to be removed or blocked for FISH analysis. To generate repeat free (RF) Probes without loss in genomic coverage, a random library is made from BAC clones by whole-genome amplification (WGA). Libraries are denatured in the presence of excess C(0)t-1 DNA and allowed to ...

In this paper, we study spectrum sensing based on dimensionality reduction and random forest (RF) in low signal-to-noise ratio environments. Classifications of three digital modulation types, including BPSK, OFDM and 2FSK, are investigated. From the received radio signal, a set of cyclic spectrum features are first calculated, and the principal component analysis (PCA) is applied to extract the...

This paper introduces a new concept in RF MEMS switches intended for high RF signal power applications at millimetre-wave operation. The novel SPST switch architecture employs electrothermal hydraulic microactuators. Out-of-plane silicon levers, having spring action and latching mechanisms, have been designed to create an OFF-state gap separation distance of 250 μm between ohmic contact electro...

Anatomical deformation caused by variable probe contact pressure is a significant problem in freehand 3D ultrasound, particularly for high resolution musculoskeletal and breast scans. We have previously published an amplitude-based algorithm for correcting such errors. In this paper, we compare this approach with a novel, elastography-inspired algorithm which works with the higher resolution ra...