scholarly journals Power-complementary IIR filter pairs with an adjustable crossover frequency

2003 ◽  
Vol 16 (3) ◽  
pp. 295-304 ◽  
Author(s):  
Ljiljana Milic ◽  
Tapio Saramaki
Keyword(s):  
Transfer Functions ◽  
Building Blocks ◽  
Crossover Frequency ◽  
Parallel Connection ◽  
Pass Filter ◽  
Design Procedures ◽  
Iir Filter ◽  
Low Pass ◽  
Q Factors ◽  
Complementary Property

This paper introduces two classes of power-complementary recursive low-pass/high-pass filter pairs with an adjustable crossover frequency in such a way that the stopband attenuation of both filters remains the same. For each class, the filter pair is constructed using two all-pass sub-filters as building blocks. Based on the properties elliptic minimal Q-factors transfer functions, simple expressions are derived for evaluating the coefficients in all-pass sections in order to achieve the desired crossover frequency. The design procedures are developed for synthesizing power-complementary filter pairs implemented as a parallel connection of two all-pass sub-filters and for the tapped cascaded interconnections of two identical all-pass sub-filters. The direct parallel connection has both the power-complementary and all-pass complementary property. The second class of filters constructed using several identical copies of the two all-pass filters possesses the power-complementary property.

Disturbance Elimination of Buck-Converter with Resonant LPF via ILQ Servo-System

2014 ◽  
Vol 492 ◽  
pp. 493-498
Author(s):  
Shuhei Shiina ◽  
Sidshchadhaa Aumted ◽  
Hiroshi Takami
Keyword(s):  
Transfer Functions ◽  
Design Method ◽  
Servo System ◽  
State Equation ◽  
Buck Converter ◽  
Linear Quadratic ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
The Stability

The proposed optimal control on the basis of both current and voltage of the buck-converter is designed to be based on Inverse Linear Quadratic (ILQ) design method with the resonant low pass filter, which eliminates the disturbance by appended disturbance compensator. The designed scheme is composed of the state equation, an optimal ILQ solution, the ILQ servo-system with the disturbance elimination, the optimal basic gain, the optimal condition, the transfer functions and the disturbance compensator. Our results show the proposed strategy is the stability and robust control and has been made to improve ILQ control for the disturbance elimination of the output response, which guarantees the optimal gains on the basis of polynomial pole assignment.

Voltage Differencing Gain Amplifier-Based nth-Order Low-Pass Voltage-Mode Filter

2018 ◽  
Vol 27 (06) ◽  
pp. 1850089 ◽  
Author(s):  
Zehra Gulru Cam Taskiran ◽  
Herman Sedef ◽  
Fuat Anday
Keyword(s):  
General Formula ◽  
Building Block ◽  
Transfer Functions ◽  
Building Blocks ◽  
Voltage Mode ◽  
Active Elements ◽  
Filter Structure ◽  
Low Pass ◽  
Minimum Number ◽  
Simple Filter

In this paper, a new active-C filter realizing the general [Formula: see text]th-order low-pass voltage transfer functions using [Formula: see text] voltage differencing gain amplifiers (VDGAs) is presented. In this realization minimum number of equal-valued grounded capacitors and [Formula: see text] active elements are used. Due to the adjustability of the transconductance of the VDGA with current, different gains can be realized using the same building block and a simple filter structure can be created. The filter which is composed of VDGA building blocks is suitable for integration and advantageous in terms of eliminating parasitic effects because all capacitors are grounded and the filter structure has no resistors. All simulations are performed on SPICE and the accuracy of this method is validated experimentally with commercially available products upon on-board circuit.

The Design of Ideal Positioning Servo System

2015 ◽  
Vol 816 ◽  
pp. 132-139
Author(s):  
Ľubica Miková ◽  
Alexander Gmiterko ◽  
Michal Kelemen
Keyword(s):  
Frequency Characteristic ◽  
Pid Controller ◽  
Transfer Functions ◽  
Servo System ◽  
Second Order ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Degree Of Stability

The paper deals with the design of an ideal positioning servo system. To achieve this aim, we will derive transfer functions of the PID controller and the second-order low-pass filter while using typical fault frequencies for PID controller with a low pass filter. Consequently, an overall frequency characteristic of the open servo system will be depicted. This characteristic will be further used to determine the amplitude and phase safety, which determine the degree of stability system.

Band-Stop Filter Algorithm Research Based on Nano-Displacement Positioning System

2013 ◽  
Vol 380-384 ◽  
pp. 697-700 ◽  
Author(s):  
Yue Zhou ◽  
Xiao Xiao Yao ◽  
Jin Xiang Pian ◽  
Yan Qiang Su
Keyword(s):  
Transfer Functions ◽  
Experimental Simulation ◽  
Infinite Impulse Response ◽  
Positioning System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Control Precision ◽  
Band Stop Filter ◽  
Low Pass ◽  
Inherent Frequency

This paper proposed the algorithms of infinite impulse response (IIR) band-stop filter and all-pass filter to eliminate the inherent frequency for piezoelectric ceramics and improve the control precision for nanodisplacement positioning system. The IIR algorithm was composed of five steps (such as the determination of normalized frequency, filter orders and transfer functions of analog low-pass filter, analog band-stop filter and digital band-stop filter). Based on the experimental simulation results on the nanodisplacement positioning platform, the butterworth band-stop filter algorithm can achieve the requested filtering effects within 10 orders .

scholarly journals On the Autonomous Gain and Phase Tailoring Transfer Functions of Symmetrically Distributed Piezoelectric Sensors

2004 ◽  
Vol 126 (4) ◽  
pp. 528-536 ◽  
Author(s):  
Yu-Hsiang Hsu ◽  
Chih-Kung Lee
Keyword(s):  
Strain Distribution ◽  
Transfer Functions ◽  
Design Concept ◽  
Piezoelectric Sensors ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Distributed Sensors ◽  
Distributed Sensor ◽  
Finite Plate ◽  
Low Pass

A new design concept for a distributed sensor, which was developed based on the principle that the strain distribution of an arbitrary finite plate structure can be expressed as the superposition of even and odd strain functions, is presented. The distributed sensors adopt a symmetric weighting electrode to match the symmetric distribution of the even parts of the strain in order to introduce a no-phase delay low-pass filter to tailor the sensor transfer function. Both the design concept and the experimental results are detailed herein.

scholarly journals A New Low-Voltage Low-Power Dual-Mode VCII-Based SIMO Universal Filter

Electronics ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 765 ◽  
Author(s):  
Leila Safari ◽  
Gianluca Barile ◽  
Giuseppe Ferri ◽  
Vincenzo Stornelli
Keyword(s):  
Low Power ◽  
Transfer Functions ◽  
Low Voltage ◽  
Supply Voltage ◽  
Building Blocks ◽  
Cmos Technology ◽  
Universal Filter ◽  
Dual Mode ◽  
Input Multiple Output ◽  
Low Pass

In this paper, a new low-voltage low-power dual-mode universal filter is presented. The proposed circuit is implemented using inverting current buffer (I-CB) and second-generation voltage conveyors (VCIIs) as active building blocks and five resistors and three capacitors as passive elements. The circuit is in single-input multiple-output (SIMO) structure and can produce second-order high-pass (HP), band-pass (BP), low-pass (LP), all-pass (AP), and band-stop (BS) transfer functions. The outputs are available as voltage signals at low impedance Z ports of the VCII. The HP, BP, AP, and BS outputs are also produced in the form of current signals at high impedance X ports of the VCIIs. In addition, the AP and BS outputs are also available in inverting type. The proposed circuit enjoys a dual-mode operation and, based on the application, the input signal can be either current or voltage. It is worth mentioning that the proposed filter does not require any component matching constraint and all sensitivities are low, moreover it can be easily cascadable. The simulation results using 0.18 μm CMOS technology parameters at a supply voltage of ±0.9 V are provided to support the presented theory.

Implications of the Born approximation for the magnetotelluric problem in three‐dimensional environments

Geophysics ◽  
1992 ◽  
Vol 57 (4) ◽  
pp. 587-602 ◽  
Author(s):  
Carlos Torres‐Verdín ◽  
Francis X. Bostick
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Born Approximation ◽  
Transfer Functions ◽  
Pass Filter ◽  
Near Surface ◽  
Low Pass ◽  
Surface Electric Field ◽  
Subsurface Resistivity ◽  
Lateral Variations

A first‐order Born approximation is obtained for the integral equations governing the surface magnetotelluric response over a three‐dimensional earth. Although accurate only in cases of low resistivity contrasts, the resulting expressions: (1) exhibit a linear relationship between a spatial perturbation in subsurface resistivity and the ensuing perturbation on the surface field response, and, more importantly, (2) allow arbitrary degrees of complexity in the geometrical characteristics of the subsurface. The linear system solutions derived from the Born approximation are studied by examining the properties of their associated kernels. These kernels may be thought of as a suite of horizontal magnetotelluric “wavelets” weighting the subsurface resistivity distribution at different depth levels. Analytical expressions for the wavelets are obtained in the wavenumber domain, thus generating a suite of magnetotelluric “transfer functions.” Expressions for the latter are particularized to the cases of one‐ and two‐dimensional geolectric media yielding results consistent with the characteristics of the magnetotelluric fields known to hold in these low‐order environments. Inspection of the electric transfer functions reveals severe sensitivity to near‐surface lateral variations of resistivity, which persists even at deep sensing frequencies. This near‐surface sensitivity is the result of an additive term in the electric field transfer functions, the static component, acting as a spatial highpass filter of the lateral variations of surface resistivity. A second additive component in the electric transfer functions, the induction component, functions as a spatial lowpass filter of the lateral variations in subsurface resistivity, and is primarily responsible for the inductive part of the surface electric field response. A common problem in magnetotelluric interpretation, the electric static effect can be reduced by inverting the role of the static component, i.e., by spatially low‐pass filtering the surface electric field. The suggested low‐pass filter for such an operation is one for which the cutoff wavenumber increases with frequency and is therefore insensitive to the response from the induction component. Low‐pass filtering of the surface electric field is best implemented in the field if the electric dipoles are deployed end‐to‐end continuously along a survey path. The magnetic field transfer functions, on the other hand, exhibit a single induction term with band‐pass filter properties which may actually lead to some amount of local distortion on the measured surface magnetic field. We propose to reduce this distortion by referring all electric field measurements to the primary magnetic field within the survey area. The primary magnetic field components, in turn, can be estimated by the spatial average of the magnetic measurements acquired at an array of magnetic stations. The suggested procedures for both the acquisition and processing of natural electric and magnetic field data encompass altogether a novel adaptation of the magnetotelluric method.

Transfer function analysis of vagal control of heart rate during synchronized vagal stimulation

1995 ◽  
Vol 269 (6) ◽  
pp. H1931-H1940 ◽  
Author(s):  
A. Mokrane ◽  
A. R. LeBlanc ◽  
R. Nadeau
Keyword(s):  
Heart Rate ◽  
Transfer Functions ◽  
Vagal Stimulation ◽  
Sinus Node ◽  
Time Interval ◽  
Pass Filter ◽  
Dynamic Component ◽  
Low Pass Filter ◽  
Transfer Function Analysis ◽  
Low Pass

Synchronized electrical stimulation was used to study the heart rate (HR) response to fluctuations in parasympathetic input to the sinus node in anesthetized dogs. This was obtained by varying the time interval (interpulse interval) between stimulatory vagal pulses. Spectral methods were used to estimate transfer functions between the excitatory signal and the resulting HR response for different intensities of vagal stimulation. The intensity of vagal stimulation was proportional to the number of pulses delivered in each cardiac cycle. From the estimated transfer functions, and based on a mathematical model of the time course of ACh concentration at the sinus node, filter models were derived by using a system identification approach. HR response was characterized by a combination of two different filter behaviors: a low-pass filter behavior of mean cut-off frequency of 0.065 Hz and an all-pass filter behavior. The magnitude of the low-pass filter gain decreased with increasing intensity of vagal stimulation. The magnitude of the all-pass filter gain increased and then decreased with increasing intensity of vagal stimulation. The all-pass filter characteristics of HR response during synchronized stimulation of the vagus nerves are specific to this mode of stimulation, because they were not observed in nonsynchronized modes of vagal stimulation. We can conclude that, during synchronized vagal stimulation, the HR response exhibits both a slow dynamic component and a fast component related to beat-to-beat variations.

scholarly journals Temporal Modulation Transfer Functions in Cat Primary Auditory Cortex: Separating Stimulus Effects From Neural Mechanisms

2002 ◽  
Vol 87 (1) ◽  
pp. 305-321 ◽  
Author(s):  
Jos J. Eggermont
Keyword(s):  
Auditory Cortex ◽  
Cortical Neurons ◽  
Transfer Functions ◽  
Frequency Tuning ◽  
Primary Auditory Cortex ◽  
Modulation Transfer ◽  
Temporal Modulation ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

We present here a comparison between the local field potentials (LFP) and multiunit (MU) responses, comprising 401 single units, in primary auditory cortex (AI) of 31 cats to periodic click trains, gamma-tone and time-reversed gamma-tone trains, AM noise, AM tones, and frequency-modulated (FM) tones. In a large number of cases, the response to all six stimuli was obtained for the same neurons. We investigate whether cortical neurons are likely to respond to all types of repetitive transients and modulated stimuli and whether a dependence on modulating waveform, or tone or noise carrier, exists. In 97% of the recordings, a temporal modulation transfer function (tMTF) for MU activity was obtained for gamma-tone trains, in 92% for periodic click trains, in 83% for time-reversed gamma-tone trains, in 82% for AM noise, in 71% for FM tones, and only in 53% for AM tones. In 31% of the cases, the units responded to all six stimuli in an envelope-following way. These particular units had significantly larger onset responses to each stimulus compared with all other units. The overall response distribution shows the preference of AI units for stimuli with short rise times such as clicks and gamma tones. It also shows a clear asymmetry in the ability to respond to AM noise and AM tones and points to a strong effect of the frequency content of the carrier on the subcortical processing of AM stimuli. Yet all temporal response properties were independent of characteristic frequency and frequency-tuning curve bandwidth. We show that the observed differences in the tMTFs for different stimuli are to a large extent produced by the different degree of phase locking of the neuronal firings to the envelope of the first stimulus in the train or first modulation period. A normalization procedure, based on these synchronization differences, unified the tMTFs for all stimuli except clicks and allowed the identification of a largely stimulus-invariant, low-pass temporal filter function that most likely reflects the properties of synaptic depression and facilitation. For nonclick stimuli, the low-pass filter has a cutoff frequency of ∼10 Hz and a slope of ∼6 dB/octave. For nonclick stimuli, there was a systematic difference between the vector strength for LFPs and MU activity that can likely be attributed to postactivation suppression mechanisms.

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