scholarly journals (N + α)-Order low-pass and high-pass filter transfer functions for non-cascade implementations approximating butterworth response

2021 ◽  
Vol 24 (3) ◽  
pp. 689-714
Author(s):  
David Kubanek ◽  
Jaroslav Koton ◽  
Jan Jerabek ◽  
Darius Andriukaitis
Keyword(s):  
Transfer Function ◽  
Fractional Order ◽  
Transfer Functions ◽  
Function Optimization ◽  
Pass Filter ◽  
Operational Transconductance Amplifiers ◽  
High Pass Filter ◽  
Approximation Errors ◽  
Low Pass ◽  
High Pass

Abstract The formula of the all-pole low-pass frequency filter transfer function of the fractional order (N + α) designated for implementation by non-cascade multiple-feedback analogue structures is presented. The aim is to determine the coefficients of this transfer function and its possible variants depending on the filter order and the distribution of the fractional-order terms in the transfer function. Optimization algorithm is used to approximate the target Butterworth low-pass magnitude response, whereas the approximation errors are evaluated. The interpolated equations for computing the transfer function coefficients are provided. An example of the transformation of the fractional-order low-pass to the high-pass filter is also presented. The results are verified by simulation of multiple-feedback filter with operational transconductance amplifiers and fractional-order element.

scholarly journals Reconfigurable Fractional-Order Filter with Electronically Controllable Slope of Attenuation, Pole Frequency and Type of Approximation

2017 ◽  
Vol 26 (10) ◽  
pp. 1750157 ◽  
Author(s):  
Jan Jerabek ◽  
Roman Sotner ◽  
Jan Dvorak ◽  
Josef Polak ◽  
David Kubanek ◽  
...  
Keyword(s):  
Fractional Order ◽  
Stop Band ◽  
Pass Band ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Operational Transconductance Amplifiers ◽  
Order Filter ◽  
Low Pass ◽  
Electronically Controllable ◽  
High Pass

This paper presents design of electronically reconfigurable fractional-order filter that is able to be configured to operate as fractional-order low-pass filter (FLPF) or fractional-order high-pass filter (FHPF). Its slope of attenuation between pass band and stop band, i.e., order of the filter, is electronically adjustable in the range between 1 and 2. Also, pole frequency can be electronically controlled independently with respect to other tuned parameters. Moreover, particular type of approximation can be also controlled electronically. This feature set is available both for FLPF and FHPF-type of response. Presented structure of the filter is based on well-known follow-the-leader feedback (FLF) topology adjusted in our case for utilization with just simple active elements operational transconductance amplifiers (OTAs) and adjustable current amplifiers (ACAs), both providing possibility to control its key parameter electronically. This paper explains how reconfigurable third-order FLF topology is used in order to approximate both FLPF and FHPF in concerned frequency band of interest. Design is supported by PSpice simulations for three particular values of order of the filter (1.25, 1.5, 1.75), for several values of pole frequency and for two particular types of approximation forming the shape of both the magnitude and phase response. Moreover, theoretical presumptions are successfully confirmed by laboratory measurements with prepared prototype based on behavioral modeling.

Pulse-shape distortion introduced by broadband deconvolution

1992 ◽  
Vol 82 (1) ◽  
pp. 238-258
Author(s):  
Stuart A. Sipkin ◽  
Arthur L. Lerner-Lam
Keyword(s):  
Transfer Function ◽  
Ground Motion ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequencies ◽  
Pass Filter ◽  
Long Period ◽  
High Pass Filter ◽  
Low Pass ◽  
High Pass

Abstract The availability of broadband digitally recorded seismic data has led to an increasing number of studies using data from which the instrument transfer function has been deconvolved. In most studies, it is assumed that raw ground motion is the quantity that remains after deconvolution. After deconvolving the instrument transfer function, however, seismograms are usually high-pass filtered to remove low-frequency noise caused by very long-period signals outside the frequency band of interest or instabilities in the instrument response at low frequencies. In some cases, data must also be low-pass filtered to remove high-frequency noise from various sources. Both of these operations are usually performed using either zero-phase (acausal) or minimum-phase (causal) filters. Use of these filters can lead to either bias or increased uncertainty in the results, especially when taking integral measures of the displacement pulse. We present a deconvolution method, based on Backus-Gilbert inverse theory, that regularizes the time-domain deconvolution problem and thus mitigates any low-frequency instabilities. We apply a roughening constraint that minimizes the long-period components of the deconvolved signal along with the misfit to the data, emphasizing the higher frequencies at the expense of low frequencies. Thus, the operator acts like a high-pass filter but is controlled by a trade-off parameter that depends on the ratio of the model variance to the residual variance, rather than an ad hoc selection of a filter corner frequency. The resulting deconvolved signal retains a higher fidelity to the original ground motion than that obtained using a postprocess high-pass filter and eliminates much of the bias introduced by such a filter. A smoothing operator can also be introduced that effectively applies a low-pass filter. This smoothing is useful in the presence of blue noise, or if inferences about source complexity are to be made from the roughness of the deconvolved signal.

ON A HIGH-PASS FILTER DESCRIBED BY LOCAL FRACTIONAL DERIVATIVE

Fractals ◽  
2020 ◽  
Vol 28 (03) ◽  
pp. 2050031 ◽  
Author(s):  
KANG-JIA WANG
Keyword(s):  
Transfer Function ◽  
Laplace Transform ◽  
Fractional Derivative ◽  
Pass Filter ◽  
Electrical Circuits ◽  
Local Fractional Derivative ◽  
High Pass Filter ◽  
Fractal Space ◽  
High Pass

The local fractional derivative (LFD) has gained much interest recently in the field of electrical circuits. This paper proposes a non-differentiable (ND) model of high-pass filter described by the LFD, where the ND transfer function is obtained with the help of the local fractional Laplace transform, and its parameters and properties are studied. The obtained results reveal the sufficiency of the LFD for analyzing circuit systems in fractal space.

scholarly journals Portable Electrocardiograph Dengan Sadapan Pada Telapak Tangan Dan Kaki

2020 ◽  
Vol 13 (2) ◽  
pp. 107-114
Author(s):  
Muhammad Syifaul Linnas ◽  
Sumber Sumber ◽  
Prastawa Assalim Tetraputra
Keyword(s):  
Personal Computer ◽  
Notch Filter ◽  
Pass Filter ◽  
Low Pass Filter ◽  
High Pass Filter ◽  
Low Pass ◽  
High Pass

    Electrocardiograph (ECG) secara rutin dilakukan oleh operator terampil yang terbiasa dengan penempatan masing-masing elektroda pada pasien. Posisi elektroda yang salah dapat menyebabkan kesalahan kritis dalam diagnosis dan perawatan penyakit jantung. Tujuan dari penelitian ini adalah mendesain sebuah Portable Electrocardiograph dengan Sadapan Pada Telapak Tangan dan Kaki. Kontribusi dari penelitian ini adalah  memudahkan orang awam dalam bidang kesehatan dalam hal penggunaan Electrocardiograph. Penelitian ini juga bertujuan  mendesain Electrocardiograph yang cukup terjangkau bagi puskesmas/pusat-pusat pelayanan medis di daerah. Agar desain ini dapat memudahkan dalam metode penggunaan alat, maka dibuatlah alat Electrocardiograph (ECG) dengan elektroda pad yang akan diletakkan pada telapak tangan dan telapak kaki yang telah di berikan tanda pada elektroda tersebut. Electrocardiograph (ECG) menggunakan desain High Pass Filter (Pasif 20dB ditambah Non Inverting Amplifier, Low Pass Filter (LPF) 40dB, dan notch filter yang akan ditampilkan pada layar monitor Personal Computer (PC). Dari hasil sadapan beberapa responden, terlihat hasil tampilan yang menyerupai/mendekati sinyal Electrocardiograph (ECG) sebenarnya. Kekurangan dari modul ini jika tidak adanya grounding yang baik dari power suply maka akan terjadi noise pada hasil sinyal yang akan ditampilkan. Hasil penelitian ini dapat di implementasikan pada Electrocardiograph (ECG) konvensional untuk meningkatkan kemudahan dalam hal penggunaan alat.    

Construction of a High-Pass Digital Filter from a Low-Pass Digital Filter

1994 ◽  
Vol 10 (4) ◽  
pp. 374-381 ◽  
Author(s):  
Stephen D. Murphy ◽  
D. Gordon E. Robertson
Keyword(s):  
Digital Filter ◽  
Low Frequency ◽  
Frequency Noise ◽  
Band Pass Filter ◽  
Low Frequency Noise ◽  
Pass Filter ◽  
Low Pass Filter ◽  
High Pass Filter ◽  
Low Pass ◽  
High Pass

To remove low-frequency noise from data such as DC-bias from electromyo-grams (EMGs) or drift from force transducers, a high-pass filter was constructed from a low-pass filter of known characteristics. A summary of the necessary steps required to transform the low-pass digital were developed. Contaminated EMG and force platform data were used to test the filter. The high-pass filter successfully removed the low-frequency noise from the EMG signals. The high-pass filter was then cascaded with the low-pass filter to produce a band-pass filter to enable simultaneous high- and low-frequency noise reduction.

scholarly journals Fractional-order high-pass filter with electronically adjustable parameters

2016 ◽  
Author(s):  
Jan Jerabek ◽  
Roman Sotner ◽  
Jan Dvorak ◽  
Lukas Langhammer ◽  
Jaroslav Koton
Keyword(s):  
Fractional Order ◽  
Pass Filter ◽  
High Pass Filter ◽  
High Pass

Design of Portable ECG Tester

2011 ◽  
Vol 328-330 ◽  
pp. 228-231
Author(s):  
Xiu Hui Fu ◽  
Hong Ru Lin ◽  
Shu Li Ouyang ◽  
Wei Bo Song
Keyword(s):  
Ecg Signal ◽  
Electrode Polarization ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Baseline Drift ◽  
Basic Frequency ◽  
The Core ◽  
High Pass Filter ◽  
Low Pass ◽  
High Pass

In order to solve the problem of ECG acquisition and processing better, this paper designs a portable ECG tester, which uses the SCM as the core controller. Power basic frequency interference was removed by 50 Hz trap filter. Power harmonic interference, electrode polarization interference and my electricity interference were removed by low- pass filter. Baseline drift was removed by high- pass filter. At the same time; we test the performance of acquisition circuit, filter circuit and amplification circuit. As a result, it is shown that the system can well collect and process ECG signal.

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