scholarly journals Low-Voltage Low-Pass and Band-Pass Elliptic Filters Based on Log-Domain Approach Suitable for Biosensors

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5581
Author(s):  
Pipat Prommee ◽  
Natapong Wongprommoon ◽  
Montree Kumngern ◽  
Winai Jaikla
Keyword(s):  
Low Voltage ◽  
Random Noise ◽  
Low Frequency ◽  
Frequency Noise ◽  
Bipolar Junction Transistor ◽  
Low Pass ◽  
Junction Transistor ◽  
Band Pass ◽  
Electronically Tunable ◽  
Log Domain

This research proposes bipolar junction transistor (BJT)-based log-domain high-order elliptic ladder low-pass (LPF) and band-pass filters (BPF) using a lossless differentiator and lossless and lossy integrators. The log-domain lossless differentiator was realized by using seven BJTs and one grounded capacitor, the lossy integrator using five BJTs and one grounded capacitor, and the lossless integrator using seven BJTs and one grounded capacitor. The simplified signal flow graph (SFG) of the elliptic ladder LPF consisted of two lossy integrators, one lossless integrator, and one lossless differentiator, while that of the elliptic ladder BPF contained two lossy integrators, five lossless integrators, and one lossless differentiator. Log-domain cells were directly incorporated into the simplified SFGs. Simulations were carried out using PSpice with transistor array HFA3127. The proposed filters are operable in a low-voltage environment and are suitable for mobile equipment and further integration. The log-domain principle enables the frequency responses of the filters to be electronically tunable between 10k Hz–10 MHz. The proposed filters are applicable for low-frequency biosensors by reconfiguring certain capacitors. The filters can efficiently remove low-frequency noise and random noise in the electrocardiogram (ECG) signal.

scholarly journals Low Frequency Noise Remove from EEG Signal

2020 ◽  
Vol 9 (1) ◽  
pp. 1510-1513
Keyword(s):  
Human Brain ◽  
Random Noise ◽  
Low Frequency ◽  
Frequency Noise ◽  
Eeg Signal ◽  
Low Frequency Noise ◽  
Frequency Range ◽  
Average Value ◽  
Different Types ◽  
The Brain

The electrical activity of the brain recorded by EEG which used to detect different types of diseases and disorders of the human brain. There is contained a large amount of random noise present during EEG recording, such as artifacts and baseline changes. These noises affect the low -frequency range of the EEG signal. These artifacts hiding some valuable information during analyzing of the EEG signal. In this paper we used the FIR filter for removing low -frequency noise(<1Hz) from the EEG signal. The performance is measured by calculating the SNR and the RMSE. We obtained RMSE average value from the test is 0.08 and the SNR value at frequency(<1Hz) is 0.0190.

Desert low-frequency noise suppression by using adaptive DnCNNs based on the determination of high-order statistic

2019 ◽  
Vol 219 (2) ◽  
pp. 1281-1299 ◽  
Author(s):  
X T Dong ◽  
Y Li ◽  
B J Yang
Keyword(s):  
Order Statistic ◽  
Seismic Data ◽  
Noise Suppression ◽  
Random Noise ◽  
Low Frequency ◽  
High Order ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
High Order Statistic ◽  
Adaptive Noise

SUMMARY The importance of low-frequency seismic data has been already recognized by geophysicists. However, there are still a number of obstacles that must be overcome for events recovery and noise suppression in low-frequency seismic data. The most difficult one is how to increase the signal-to-noise ratio (SNR) at low frequencies. Desert seismic data are a kind of typical low-frequency seismic data. In desert seismic data, the energy of low-frequency noise (including surface wave and random noise) is strong, which largely reduces the SNR of desert seismic data. Moreover, the low-frequency noise is non-stationary and non-Gaussian. In addition, compared with seismic data in other regions, the spectrum overlaps between effective signals and noise is more serious in desert seismic data. These all bring enormous difficulties to the denoising of desert seismic data and subsequent exploration work including geological structure interpretation and forecast of reservoir fluid. In order to solve this technological issue, feed-forward denoising convolutional neural networks (DnCNNs) are introduced into desert seismic data denoising. The local perception and weight sharing of DnCNNs make it very suitable for signal processing. However, this network is initially used to suppress Gaussian white noise in noisy image. For the sake of making DnCNNs suitable for desert seismic data denoising, comprehensive corrections including network parameter optimization and adaptive noise set construction are made to DnCNNs. On the one hand, through the optimization of denoising parameters, the most suitable network parameters (convolution kernel、patch size and network depth) for desert seismic denoising are selected; on the other hand, based on the judgement of high-order statistic, the low-frequency noise of processed desert seismic data is used to construct the adaptive noise set, so as to achieve the adaptive and automatic noise reduction. Several synthetic and actual data examples with different levels of noise demonstrate the effectiveness and robustness of the adaptive DnCNNs in suppressing low-frequency noise and preserving effective signals.

A NEW ELECTRONICALLY-TUNABLE ACTIVE-ONLY UNIVERSAL BIQUAD

2011 ◽  
Vol 20 (03) ◽  
pp. 549-555 ◽  
Author(s):  
A. K. SINGH ◽  
R. SENANI ◽  
D. R. BHASKAR ◽  
R. K. SHARMA
Keyword(s):  
Pass Band ◽  
Voltage Mode ◽  
Op Amp ◽  
Op Amps ◽  
Reasonable Number ◽  
Low Pass ◽  
Band Pass ◽  
Electronically Tunable ◽  
High Pass ◽  
Realization Condition

A number of configurations for realizing voltage-mode (VM) biquads using op-amps and OTAs have been presented in the literature, however, none of these provide the following desirable properties simultaneously: (i) realizability of all the five standard filters (namely; low pass, high pass, band pass, band stop and all pass), (ii) tunability of all the three filter parameters (namely; ω0, bandwidth or Q0 and gain) and (iii) not requiring any realization condition in any of the five filter responses. This paper presents a new configuration which does possess all the above mentioned desirable properties simultaneously while using only two internally-compensated type op-amps and a reasonable number of OTAs. The workability of the new configuration has been demonstrated by SPICE simulations based upon CMOS Op-amp and CMOS OTAs.

MIXED MODE UNIVERSAL FILTER

2013 ◽  
Vol 22 (01) ◽  
pp. 1250064 ◽  
Author(s):  
NEETA PANDEY ◽  
SAJAL K. PAUL
Keyword(s):  
Mixed Mode ◽  
Cmos Technology ◽  
Output Impedance ◽  
Universal Filter ◽  
Output Current ◽  
Voltage Signal ◽  
Low Pass ◽  
Band Pass ◽  
Electronically Tunable ◽  
High Pass

The configuration with electronic tunable characteristics that can work in mixed mode may be useful from IC realization viewpoint and application adaptability. This paper proposes an electronically tunable mixed mode universal filter based on multiple output current controlled current conveyor (MOCCCII) and this single topology without any alteration can be used in all four modes i.e., voltage (VM), current (CM), transimpedance (TIM) and transadmittance (TAM). The architecture uses four MOCCCIIs and two grounded capacitors; and can realize universal filter functions — low pass (LP), band pass (BP), high pass (HP), notch (NF) and all pass (AP) for all four modes. Moreover the input impedance is high and output impedance is low for voltage signal and vice-versa for current signal, hence the proposed topology is suitable for cascading for all four modes. The workability of the proposed circuit has been verified via SPICE simulations using AMS 0.35 μm CMOS technology.

scholarly journals Study of rogue wave by low-pass filtered noise in a multistable fiber laser

2013 ◽  
Vol 23 ◽  
pp. 23-26
Author(s):  
R. Sevilla Escoboza ◽  
G. Huerta Cuéllar ◽  
J. García López ◽  
D. López Mancilla ◽  
C. Castañeda Hernández ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Rogue Wave ◽  
Low Frequency ◽  
Pump Current ◽  
Rogue Waves ◽  
High Amplitude ◽  
Frequency Noise ◽  
Level Laser ◽  
Low Pass ◽  
Filtered Noise

Clear evidence of rogue waves in a multistable system is revealed with an erbium-doped fiber laser driven by harmonic pump modulation (Pisarchik, Jaimes-Reátegui, Sevilla-Escoboza, Huerta-Cuellar & Taki, 2011). We demonstrate numerically and experimentally that a low-pass noise filtering can control the probability for the appearance of a particular state. The results of numerical simulations with the use of a three-level laser model display good agreement with experimental results. The mechanism for the rogue wave formation lies in the interplay of stochastic processes with multistable deterministic dynamics. Low-frequency noise applied to a diode pump current induces rare jumps to coexisting subharmonic states with high-amplitude pulses perceived as rogue waves. The probability of these events depends on the noise filtered frequency and grows up when the noise amplitude increases. The probability distribution of spike amplitudes confirms the rogue wave character of the observed phenomenon.

Electronically-Tunable Current-Mode Biquad Design Using MO-OTAs

2016 ◽  
Vol 25 (09) ◽  
pp. 1650107 ◽  
Author(s):  
Ali Kircay ◽  
Selim Borekci
Keyword(s):  
Quality Factor ◽  
Current Mode ◽  
Center Frequency ◽  
Total Power ◽  
Operational Transconductance Amplifiers ◽  
Single Output ◽  
Low Pass ◽  
Band Pass ◽  
Electronically Tunable ◽  
Dc Current

In this paper, electronically-tunable, current-mode biquad is proposed by using multiple-output operational transconductance amplifiers (MO-OTAs). The proposed circuit has one input and two outputs. Without changing the circuit topology, low-pass (LP), and band-pass (BP) responses can be realized. The filter is realized by using two MO-OTAs, a single-output OTA (SO-OTA), a two-output OTA and two grounded capacitors. The biquad is designed based on first-order LP filter or lossy integrator blocks. The feedback block is applied to the filter circuit in order to obtain high quality factor values greater than 1/2. The center frequency and the quality factor of the LP and BP filters can be electronically tuned by DC current of OTAs. The total power dissipation of the proposed biquad is approximately 10[Formula: see text]mW at [Formula: see text][Formula: see text]V supplied voltage. The theoretical analysis is also confirmed with SPICE simulations.

Infrasound — Tutorial and Review: Part 1

1983 ◽  
Vol 2 (3) ◽  
pp. 1-31 ◽  
Author(s):  
O. Backteman ◽  
J. Köhler ◽  
L. Sjöberg
Keyword(s):  
Home Environment ◽  
Leisure Time ◽  
Random Noise ◽  
Low Frequency ◽  
Sound Level ◽  
Frequency Noise ◽  
Full Agreement ◽  
Normal People ◽  
Short Time ◽  
Frequency Area

Infrasound is everywhere. Even in an environment that is very quiet, infrasound levels of 40 dB(IL) (2–20 Hz) can be measured. Results from numerous investigations about the influence of infrasound on people and animals have been published during the last 20 years. What all these investigations have in common is that only short time exposures have been investigated i.e. infrasound exposures during minutes or hours. Discrete frequencies in the range of 4–16 Hz have often been used instead of low frequency random noise spectra. The results of these investigations vary considerably, which may be due to the fact that there has not been equal excitation. In certain experiments and reports the stimuli spectra are often not accounted for. If they are accounted for this is done inadequately. This is also true for the way the results have been treated. Some conclusions that have been made have to be seen as spectacular! Several scientists have pointed out that the results may be caused by stimulus in the audible range, not by infrasound. At the conference “Low frequency noise and hearing” (May 1980 in Aalborg, Denmark), where most of the leading scientists of the low frequency area participated, it was stated that there are people who seem to be more sensitive to low frequency disturbances than others. In general, infrasound should not be a direct problem for normal people, which these research results showed. There was full agreement that there is not enough research being done today on low frequency disturbances in the range of 20–100 Hz. These disturbances cannot be sufficiently indicated by measuring the sound level in dB(A). The participants seemed quite convinced that people are irritated by low frequency disturbances both during work, at home and during leisure time. This has not been sufficiently noted. Most machines in industries and in homes also have frequencies in the region of 50 Hz, e.g. transformers, compressors, diesel- and gas motors, electric motors and fans. The objective of this work has been to make a comprehensive review, especially in accounting for infrasound levels under normal working conditions and in home environment, both in Sweden and in the rest of the world. Due to the fact that the results from different reports are not uniform and often incomplete, a direct comparison of results is not possible.

Required Data Collection Times for Steady and Quasi-steady Experiments

2017 ◽  
Author(s):  
Robert F. Roddy ◽  
David E. Hess
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Frequency Noise ◽  
Surface Ship ◽  
System A ◽  
Low Pass ◽  
Collection Period ◽  
Almost All ◽  
Low Pass Filters

One of the requirements in performing steady or quasi-steady experiments is the determination of adequate collection times so that the data will not be biased due to low frequency energy in the data stream. Since virtually all steady experiments run at DTMB have low pass filters in line with the signal conditioning, high frequency noise is not a consideration in determining the required collection times. At both EMB and DTMB almost all of the surface ship drag measurements were made using gravity type balances until about 1970. These balances used both springs and dampers to modify the natural frequency of the system so that a good average model drag could be determined in a 5-6 sec collection period. Submarine model experiments began using block gages to measure drag beginning in the late 1950's. For these experiments crude methods were used to damp the output data but, to the author’s knowledge, no methods were ever put into place that was analogous to the springs and damper system. A method for determining the required collection times for any steady or quasi-steady experiment is presented along with sample cases showing the necessity for, and the utility of, using such a method.

scholarly journals Stability of pulsar rotational and orbital periods

2009 ◽  
Vol 5 (H15) ◽  
pp. 226-227
Author(s):  
Sergei Kopeikin
Keyword(s):  
General Relativity ◽  
Time Scale ◽  
Random Noise ◽  
Low Frequency ◽  
Frequency Noise ◽  
Tests Of General Relativity ◽  
Orbital Parameters ◽  
Pulsar Timing ◽  
Orbital Periods ◽  
The Stability

AbstractMillisecond and binary pulsars are the most stable astronomical standards of frequency. They can be applied to solving a number of problems in astronomy and time-keeping metrology including the search for a stochastic gravitational wave background in the early universe, testing general relativity, and establishing a new time-scale. The full exploration of pulsar properties requires that proper unbiased estimates of spin and orbital parameters of the pulsar be obtained. These estimates depend essentially on the random noise components present in pulsar timing residuals. The instrumental white noise has predictable statistical properties and makes no harm for interpretation of timing observations, while the astrophysical/geophyeical low-frequency noise corrupts them, thus, reducing the quality of tests of general relativity and decreasing the stability of the pulsar time scale.

Low Frequency Incremental Collector Output Resistance of a Bipolar Junction Transistor

1981 ◽  
Vol 18 (3) ◽  
pp. 257-265
Author(s):  
B. L. Hart
Keyword(s):  
Minority Carrier ◽  
Low Frequency ◽  
Base Region ◽  
Device Structure ◽  
Output Resistance ◽  
Bipolar Junction Transistor ◽  
Junction Transistor ◽  
Carrier Charge ◽  
Emitter Voltage

A basic consideration of the variation, with collector-emitter voltage, of the minority carrier charge in the emitter as well as the base region of a bipolar junction transistor facilitates a didactic treatment of the dependence of low frequency collector output resistance on aspects of device structure and modelling, and base-emitter circuit drive conditions.

Sign in / Sign up

Export Citation Format

Share Document