This series of articles discusses oscillator phase noise reduction techniques and gives specific resonant circuit solutions using lumped and distributed parameters for both frequency stabilization and phase noise reduction. These topics are covered in Part 1. Phase noise improvement can also be achieved by appropriate low-frequency loading and feedback circuitry optimization. The feedback syste...

We measured the eVect of global phase manipulations on a rapid animal categorization task. The Fourier spectra of our images of natural scenes were manipulated by adding zero-mean random phase noise at all spatial frequencies. The phase noise was the independent variable, uniformly and symmetrically distributed between 0° and §180°. Subjects were remarkably resistant to phase noise. Even with §...

This brief presents experimental and modeling results of device noise in SiGe HBT RF technology. By careful bandgap engineering, a simultaneous reduction of RF noise, 1 noise, and phase noise has been achieved. At a given , transistors with different base bandgap profiles show similar 1 noise. At a given , however, transistors with a higher (and hence lower RF noise) show lower 1 noise. Circuit...

In this paper, a special preprocessing operations (filter) is proposed to decrease the effects of noise of textures. This filter using average of circular neighbor points (Cmean) to reduce noise effect. Comparing this filter with other average filters such as square mean filter and square median filter indicates that it provides more noise reduction and increases the classification accuracy...

Post-acquisition processing of MRI images to remove noise can potentially improve their diagnostic value. Currently there are many suggested wavelet thresholding algorithms for denoising MRI data with most of them focused on magnitude-reconstructed images. An alternate approach is to correct phase errors in the image and then take the real value of each pixel as the grayscale intensity. We pres...

Improved phase space projection methods, adapted from related work in the linear signal processing field based on subspace decomposition, are presented for application to the problem of additive noise reduction in the context of phase space analysis. These methods improve upon existing methods such as Broomhead–King singular spectrum analysis projection by minimizing overall signal distortion s...

Introduction MRI is a phase sensitive detection system and both magnitude and phase time-series are obtained in an fMRI study. The possibility to use both image sets for the statistical evaluation of fMRI has been proposed (1-2). The raw phase values are proportional to the local voxel-averaged magnetic field and are generally dominated by Bo field inhomogeneities, that are time-dependent in th...

To see how our Project Lock-In works, have a look at the Schematic I. You will find there the internal electronic components of the instrument and their interconnections. The most essential parts to make the Lock-In work as such, are a multiplier circuit and a low pass circuit, or integrator, which together form a “PhaseSensitive Detector", or PSD. For reasons you will immediately understand, a...

Spin torque oscillators (STOs) are compact, tunable sources of microwave radiation that serve as a test bed for studies of nonlinear magnetization dynamics at the nanometer length scale. The spin torque in an STO can be created by spin-orbit interaction, but low spectral purity of the microwave signals generated by spin orbit torque oscillators hinders practical applications of these magnetic n...

This paper reviews several techniques used to reduce the in-band phase noise contribution of fractional-N frequency synthesizers. The paper develops several practical techniques for specifying the noise and linearity of components used in a fractional-N synthesizer. As an example, it presents a synthesizer with an in-band phase noise floor of 97 dBc/Hz@10 KHz for an RF output frequency of 2.432...