In this paper, an intuitive analysis of a phase noise reduction technique is done, and then a modified structure is proposed to achieve higher phase noise reduction than the original one. This method reduces the impact of noise sources on the phase noise by decreasing closed-loop gain in zero-crossings points and moving this high closed-loop gain to the non-zero-crossings points. This reduction...

sound power is considered as an excellent measure for evaluating the efficiency of noise controls as well as for comparing noise sources in workrooms. this parameter can be determined by sound pressure or intensity based methods in real conditions of workrooms. this paper aims empirically to compare these in situ methods in relation to a typical industrial machine located in workroom in terms o...

background: noise can cause permanent or temporary hearing loss. high levels of noise may stimulate the vestibular system and thereby cause disturbances in the balancing mechanism. objective: to determine the effect of long-term exposure to occupational noise on the vestibular system. methods: a dizziness questionnaire was administered to 20 factory workers who were exposed to occupational nois...

The sources of human exposure to low-frequency noise and its effects are reviewed. Low-frequency noise is common as background noise in urban environments, and as an emission from many artificial sources: road vehicles, aircraft, industrial machinery, artillery and mining explosions, and air movement machinery including wind turbines, compressors, and ventilation or air-conditioning units. The ...

accuracy of inertial navigation system (ins) is limited by inertial sensors imperfections. before using inertial sensors signals in the data fusion algorithm, noise removal method should be performed, in which, wavelet decomposition method is used. in this method the raw data is decomposed into high and low frequency data sets. in this study, wavelet multi-level resolution analysis (wmra) techn...

background: noise pollution is one of the most harmful ambiance disturbances. it may cause many deficits in ability and activity of persons in the urban and industrial areas. it also may cause many kinds of psychopathies. therefore, it is very important to measure the risk of this pollution in different area. methods: this study was conducted in the department of medical physics and biomedical ...

This paper gives an overview of the physics and modeling of noise in SiGe HBT devices and circuits, including RF broadband noise, low-frequency noise, and oscillator phase noise. The ability to simultaneously achieve high cutoff frequency (fT ), low base resistance (rb), and high current gain (β) using Si processing underlies the low levels of low frequency 1/f noise, RF noise and phase noise o...

in this paper, a new high dynamic range digitally-controlled oscillator (dco) for all-dpll systems is proposed. the proposed dco is based on using a δς modulator as a digital-to-analog converter. using δς dac can provide a very high resolution (18-bit) control on the dco. the δς dac output is a 2-level pulse signal that needs to be filtered for cancelling the out of band shaped noise. the used ...