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A non-Foster circuit has been designed for broadband matching of antenna impedance. This matching network is used to achieve bandwidths for electrically small antenna (ESA) that exceed Chu's limit for passive antennas. The study of noise in non-Foster matching circuits is critical because of the effects of active components on the signal to noise ratio (SNR). This is specifically important for receive-type...
Clock jitter is a crucial factor in high speed and high performance Analog-to-Digital Converter (ADC) testing. Random clock jitter increases the noise floor in the ADC output spectrum making it difficult to obtain the true ADC Signal to Noise Ratio (SNR). Periodic Jitter generates spurs in the ADC output spectrum. Another well-known challenge is to achieve precise coherent sampling. This paper proposes...
Image Enhancement is a process of improving the quality of an image by improving the contrast of the images. Images acquired underwater usually suffers from non-uniform illumination, low-contrast, motion blur effect due to turbulence in the flow of water, in under ocean environment, scattering of light from different particles of various sizes, diminished intensity and color level due to poor visibility...
In this paper we consider an acoustic scenario with a desired source and a directional interference picked up by hearing devices in a noisy and reverberant environment. We present an extension of the binaural multichannel Wiener filter (BMWF), by adding an interference rejection constraint to its cost function, in order to combine the advantages of spatial and spectral filtering while mitigating directional...
Spectrum sensing is one of the most crucial tasks a cognitive radio has to carry out in order to decide whether a licensed spectrum can be used without causing interference to the licensed or the Primary Users (PU). Many techniques exist in the literature for satisfactory detection performance. However, in many cases, an additive white Gaussian noise is assumed, which is an oversimplified assumption...
Improvement in quality as well as intelligibility is the prime requirement of speech enhancement devices such as hearing aids. Understanding speech signals can be very difficult for hearing impaired as well as normal hearing listeners especially when background noise is present. Majority of the traditional speech enhancement algorithms have reported improvement in quality but not necessarily intelligibility...
Electrocardiogram (ECG) signals usually corrupted by different types of noise like power line interference, baseline drift due to respiration, electromyogram interference, abrupt baseline shift and their composite noise. Denoising of noisy signal has great clinical importance for the diagnosis of cardiac abnormalities. In this paper, dual tree complex wavelet transform (DTCWT) has been used to denoise...
Munesh Chandra Trivedi Dept. Of Computer Science & Engineering ABES Engineering College, Ghaziabad, India Audio watermarking becomes buzzword in multimedia industry. The protection of ownership for audio clip is very critical issue in the field of multimedia industry. In this paper we present a novel approach for watermarking the audio signal samples by masking the audio samples to generate...
The paper describes the mechanism of Agilent 3458A sampling time jitter present when external triggering is used at synchronous two channel sampling. Based on measurements it is shown that the master DMM adds approximately 3.2 ns of its own time jitter while triggering the slave DMM and that the effective time jitter for externally triggered DMM remains at 7 ns, well below ±50 ns maximum jitter as...
We performed a Signal to Noise Ratio characterization, in the continuous wave regime, at different bias voltages, frequencies and temperatures, on a novel class of silicon photomultipliers fabricated in planar technology on silicon p-type substrate. Signal to Noise Ratio has been measured as the ratio of the photogenerated current, filtered and averaged by a lock-in amplifier, and the Root Mean Square...
Jitter is a crucial factor in high speed and high performance ADC testing. This paper proposes an efficient and accurate jitter estimation method based on one frequency measurement. Applying simple mathematical processing to the ADC output in time domain, the RMS of jitter and noise power are obtained. Furthermore, prior information of harmonics does not need to know before the processing. The algorithm...
Electrocardiogram ECG signal is usually corrupted by several artifacts and these must be removed before diagnosis. This paper therefore presents the design of various FIR filters like Kaiser, Rectangular, Hamming, Hanning, Gaussian and Bartllet window techniques and FIR Equiripple Filter. IIR filters like Butterworth, Chebychev I & II and Elliptic Filters are also explored to remove the artifacts...
Noise is the key to cause phase measurement error of sine signals. Although there have been many attempts to suppress noise interference, high accuracy is still hard to meet in terrible noise environment. In order to improve reliability and accuracy of the measurement system, a robust method is proposed. In this paper, independent component analysis (ICA) is used to separate sine signal from noises...
This paper reports on the state of the art silicon micromachined microphone utilizing a dual poly silicon membrane system. MEMS chips from 1.4mm down to 1.0mm side length are applied for mobile communication. Design aspects related with key performance parameters such as sensitivity, signal to noise ration and distortion are discussed. Sensitivity of − 38BV/Pa is achieved for different microphone...
In conjunction with the problem of the target selection on a clutter background with quasi-continuous radiation, the analysis of the spatial radar signal processing is made. The analysis is made for a case of non-isotropic array elements. The calculation results of the optimized receiving antenna pattern and the attained signal-to-noise ratio for the confirmation of the efficiency of the cylindrical...
Myoelectric Signals (MES) have a long traditionwith regard to prostheses control. Due to the signals' nature, MES are prone to interference and noise. Various methods existfor preprocessing these signals before classification algorithmsto derive control information are applied. While these methodshelp to improve the source signals, parameters must be carefullyselected and implemented on a case-to-case...
The fabrication of silicon-substrate multi-channel microelectrode arrays for single neuron recording as well as modification of two materials to optimize the neural tissue-electrode interface were investigated. By use of multi-project wafer (MPW) model, six kinds of microelectrode arrays with different recording sites arrangement were simultaneously fabricated from one 4-inch wafer. To improve electric...
In this paper, a noise robust formant frequency estimation scheme is developed utilizing the advantageous properties of the autocorrelation function of the band-limited noisy speech signal. It is shown that the use of autocorrelation operation on a speech signal, which is band-limited to a particular formant zone, in comparison to one without any band limitation, can provide higher noise immunity,...
This paper shows a method of WDR (wide dynamic range) in camera. When we make a digital WDR, commonly we meet two problems. The first one is an increase of noise. And the other is a lot of control factors. In this paper we will show a WDR with low noise and small number of control factors. The circuit is very simple and needs no memory. So the chip size is nearly unchanged after implementation. When...
In this article I present the components of a circuit that is designed to improve the signal/noise communications using frequency modulation. Circuit was made interposing between two active filters, Sallen-Key second order, a non-inverting amplifier. The proposed scheme was analyzed with the program Macker circuit and voltage dependence graph/time has been translated in coordinates voltage/frequency...
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