Order Low Pass Research Articles

Analysis and Simulation of the Impact of Gamma parameter and Phase Noise on Phase-Locked Loop with PID Controller

In this work, detailed simulation and analysis of impact of gamma parameter and phase noise on the proportional-integral-derivative controlled phase-locked loop is carried out. The linear mathematical model for gamma parameter along with the phase noise model of the proposed system is developed. To improve the loop dynamics, a new type of loop filter is designed by considering a parallel combination of second order passive low pass filter and a proportional-integral-derivative controller in place of the traditional loop filter. The transfer function of gamma parameter as well as noise sources of each component of the phase-locked loop is derived from the proposed model in s-domain. Simulation is carried out on MATLAB to study how gamma parameter impacts on system response as well as on the phase noise contribution to the proposed system. The impact of gamma parameter on lock time, phase margin and loop bandwidth is also studied for gamma parameter less than one and greater than one. Finally, a comparison is done between second order low pass filter, proportional-integral-derivative controller and the newly designed loop filter. Simulation results shows that the proposed system with newly designed loop filter improves the system stability with fast switching speed and reduced the phase noise with gamma greater than one.

Effect of Pulse Duration and Direction on Plasticity Induced by 5 Hz Repetitive Transcranial Magnetic Stimulation in Correlation With Neuronal Depolarization.

Introduction: High frequency repetitive transcranial magnetic stimulation applied to the motor cortex causes an increase in the amplitude of motor evoked potentials (MEPs) that persists after stimulation. Here, we focus on the aftereffects generated by high frequency controllable pulse TMS (cTMS) with different directions, intensities, and pulse durations.Objectives: To investigate the influence of pulse duration, direction, and amplitude in correlation to induced depolarization on the excitatory plastic aftereffects of 5 Hz repetitive transcranial magnetic stimulation (rTMS) using bidirectional cTMS pulses.Methods: We stimulated the hand motor cortex with 5 Hz rTMS applying 1,200 bidirectional pulses with the main component durations of 80, 100, and 120 μs using a controllable pulse stimulator TMS (cTMS). Fourteen healthy subjects were investigated in nine sessions with 80% resting motor threshold (RMT) for posterior-anterior (PA) and 80 and 90% RMT anterior-posterior (AP) induced current direction. We used a model approximating neuronal membranes as a linear first order low-pass filter to estimate the strength–duration time constant and to simulate the membrane polarization produced by each waveform.Results: PA and AP 5 Hz rTMS at 80% RMT produced no significant excitation. An exploratory analysis indicated that 90% RMT AP stimulation with 100 and 120 μs pulses but not 80 μs pulses led to significant excitation. We found a positive correlation between the plastic outcome of each session and the simulated peak neural membrane depolarization for time constants >100 μs. This correlation was strongest for neural elements that are depolarized by the main phase of the AP pulse, suggesting the effects were dependent on pulse direction.Conclusions: Among the tested conditions, only 5 Hz rTMS with higher intensity and wider pulses appeared to produce excitatory aftereffects. This correlated with the greater depolarization of neural elements with time constants slower than the directly activated neural elements responsible for producing the motor output (e.g., somatic or dendritic membrane).Significance: Higher intensities and wider pulses seem to be more efficient in inducing excitation. If confirmed, this observation could lead to better results in future clinical studies performed with wider pulses.

Frequency Response of Electronically Tunable Current-Mode Third Order High Pass and Low Pass Filter for Q = 10

The circuits using current-mode (CM) building blocks have received considerable attention in many filtering and signal processing applications. Compared to their voltage-mode(VM) counterparts, the current-mode building blocks are attractive because of their wider bandwidth, higher slew rate, and lower power consumptions. In IC technology, it is desirable to operate circuits at low voltages which can be achieved by using CM building blocks. As a large number of op-amp based circuits with elegant realization procedures are already available, it is worthwhile to convert them into the circuits based on current-mode building blocks. In this paper, a realization of a current mode third order high pass and low pass filter is described. The proposed circuit employs operational amplifier as the basic building unit. The filter circuit realizes quadratic work function. It provides electronically tuning capability of the filter characteristics. The proposed circuit works ideal for Center frequency fo= 10 k and Circuit merit factor Q > 1. The gain roll-off this configuration is 18dB/octave. The circuit is suitable for monolithic integration and high frequency operation. The filters developed were successful in obtaining passive sensitivities less than unity in magnitude and active sensitivities are half in magnitude, which is a noteworthy achievement. The circuit is suitable for high frequency operation and monolithic integration.

An effective analog circuit design of approximate fractional-order derivative models of M-SBL fitting method

There is a growing interest in fractional calculus and Fractional Order (FO) system modeling in many fields of science and engineering. Utilization of FO models in real-world applications requires practical realization of FO elements. This study performs an analog circuit realization of approximate FO derivative models based on Modified Stability Boundary Locus (M-SBL) fitting method. This study demonstrates a low-cost and accurate analog circuit implementation of M-SBL fitting based approximate model of FO derivative elements for industrial electronics. For this purpose, a 4th order approximate derivative transfer function model of the M-SBL method is decomposed into the sum of first order low-pass filters form by using Partial Fraction Expansion (PFE) method, and the analog circuit design of the approximate FO derivative model is performed. Firstly, by using the final value theorem, authors theoretically show that the time response of the sum of first order low-pass filter form can converge to the time response of fractional order derivative operators. Then, the approximation performance of proposed FO derivative circuit design is validated for various input waveforms such as sinusoidal, square and sawtooth waveforms via Multisim simulations. Results indicate an accurate realization of the FO derivative in time response (an RMSE of 0.0241). The derivative circuit realization of the M-SBL fitting model in the form of the sum of first order low pass filters can yield a better time response approximation performance compared to the Continued Fraction Expansion (CFE) based ladder network realization of the approximate derivative circuit.

Electronic Tuneable Grounded and Floating FDNR using FTFNTA

ABSTRACT In this manuscript, an electronically tunable resistor-less grounded and floating FDNR (Frequency-Dependent Negative Resistance) is presented. The proposed circuit uses two FTFNTAs (Four Terminal Floating Nullor Transconductance Amplifier) and three capacitors for the design of floating FDNR; while only one FTFNTA and two capacitors are used for the design of grounded FDNR. The electronic tunability is achieved by altering the bias current of the FTFNTA. The workability of the proposed FDNR is demonstrated through the implementation of 4th order Butterworth band pass filter (BPF) and 2nd order low pass filter (LPF). The PSPICE simulation results are included to verify the theoretical interpretation.

D STATCOM Control using SRFT Method for PQ Improvement in a PV System

The set of restrictions defined for a system’s electrical characteristics so that the entire electrical system can function in the intended manner and without losses is known as power quality. Power quality issues such as transients, harmonics, voltage swell, sag, flicker, fluctuations, and power factor difficulties are becoming more common as power electronic devices become more widely used. The usage of a Distribution Static Compensator (D-STATCOM) to mitigate power quality issues is discussed in this study. In this case, D-STATCOM functions as a shunt active power filter to reduce harmonics caused by non-linear loads. The simulation studies on a PV-based Cascaded-H-Bridge Multi-Level Inverter i.e Solar PV and Cascaded H Bridge MLI are integrated using Selective Harmonic Elimination method with D-STATCOM injected at the load side to improve power quality are presented in this project. The Solar PV system is mathematically modelled using Boost regulator and P&O MPPT technique and to the D-STATCOM the controller is designed utilizing Synchronous Reference Frame Theory (SRFT) out of many control strategies for reactive power compensation, harmonic mitigation, and power factor enhancement as it is more accurate. A 2nd order low pass filter is employed at the load side to reduce the harmonics to some extent, and both 5-level and 7-level models are evaluated. MATLAB/SIMULINK is used for simulation.

MOS-C Based Electronically Tuneable Current/Voltage-Mode Third Order Quadrature Oscillator and Biquadratic Filter Realization

This paper introduces a new electronically tuneable third order quadrature oscillator and biquadratic filter with MOS-C realization using all grounded passive components. Voltage-mode second order low-pass, high-pass, band-pass filters using second generation current conveyor and a current/voltage-mode third order quadrature sinusoidal oscillator using multi-output second generation current conveyor are synthesized from the proposed circuit topology. All synthesized circuits are compatible with integration and the center frequency can be electronically tuned by the gate voltage of the MOS transistors. The proposed circuits do not need any component matching condition. Oscillation condition and frequency of oscillation can be independently controlled. Workability of the proposed circuits is validated by PSPICE software using 0.18 micrometer MOSIS CMOS process parameters at ±0.9 V supply voltage. Tuneability of the oscillator is demonstrated for a tested frequency range both in voltage-mode and current-mode operations.

(N + \u03b1)-Order low-pass and high-pass filter transfer functions for non-cascade implementations approximating butterworth response

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.

Ultra Low Frequency Wide Band Low Pass Active Filter for Bio-Medical Applications Simulated on Cadence tool

An ultra low frequency wide band low pass active filter is designed and simulated on 180nm cadence virtuoso tool for biomedical applications in this paper. This proposed designed low pass active filter is being able to stop low frequency signal of µHz and can pass up to Hz using the CMOS nanotechnology. This is a second order low pass active filter. It can be useful to identify the human disease by detecting ultra low frequency bio-signal. The simulated result shows ultra low power consumption of 200pW with high bandwidth at 1mV input supply.

Filter Design for A Fractional N-PLL Frequency Synthesizer At 2.4 GHz

Radio frequency transmitter and receivers usually needs an efficient frequency synthesizer, and this synthesizer must use a digital electronic circuit to perform different modern digital application which contain a frequency synthesizer circuit as a main part of the circuits. The fractional-N phase locked loop (PLL) has been used widely in the last twenty year ago because it gives a large bandwidth with fine frequency resolution for various electronic applications. This research presents the design of second order low pass filter at a frequency bandwidth of (50,75,125,250,500) kHz and for each value of the phase margin (30,35,40,47,57,65,70,80) degree, the component values of the filters which the capacitors and resistance were found at each values of the frequency bandwidth and for each phase margin, also the filter impedance, open loop and closed loop gain was calculated, it is found that by proper design of the second order low pass filter component, the system can have more stability operation and the spurs noise in the output can be reduced efficiently.

Design and Implementation of Third Order Low Pass Digital FIR Filter using Pipelining Retiming Technique

This paper presents design and implementation of 3rd order low pass digital FIR filter using pipelining retiming technique. Aim of this paper is to apply pipelining retiming technique on low pass digital FIR filter and compare with the existing second order retimed FIR filter and third order broadcast, non-broadcast low pass FIR filter. MATLAB FDA tool is used to calculate digital FIR filter coefficients. Hamming and Kaiser window methods are used to find out the coefficients of the FIR filter. Broadcast and non broadcast third order low pass FIR filter architectures are used for pipelining retiming .Cutset and feed forward pipelining retiming techniques are used to retime the third order low pass digital FIR filter. We design our algorithm in VHDL and implemented on Xilinx Vivado xc7a35tcpg261-1. Area (LUT), speed and power are calculated using Xilinx Vivado 2015.2 tool. Synthesis and simulation results are discussed in this paper. Speed and area (LUT) of proposed third order low pass FIR filter is improved in comparison with existing designs.

Simulasi Perbandingan Filter Savitzky Golay dan Filter Low Pass Butterworth pada Orde Ketiga Sebagai Pembatal Kebisingan

Nowadays, the Information and Communication Technology (ICT) is rapidly developed. It also trigs the development of other research field such as social science research. But in the development of it, there are a continues problem that has been discovered over 30 years, noise. Over the years, many ways have been created for example Savitzky – Golay (SG) and Low Pass (LP) Butterworth filter. In order to use SG filter, two parameters which are the order and the window length should be determined by trial and error. On the other hand, LP Butterworth filter also needs two parameters to be operated which are the order and the cut off frequency. This research focuses on comparing the performance of third order LP Butterworth filter and third order SG filter by finding the gap between filtered signal and the original signal through the simulation by using MATLAB. This research is supported by the journals and books references. Also, the data of this research is presented by the table and graph. According to this research, founded that both filters have a significant impact to smoothing the noisy signal. compare to LP Butterworth filter, SG filter has better performance. It is proven by SG filter only has 5% gap to the original signal where LP Butterworth filter has a slightly bigger gap, 8.82%.

Analysis and Design of Optimized Fractional Order Low-Pass Bessel Filter

This paper approximates the behavior of low-pass Bessel filter in fractional domain using the Interior search algorithm (ISA). A detailed analysis has been done with sensitivity analysis, W-plane stability and absolute percentage error (gain and cut-off frequency) to study the low-pass fractional order filter. The work focuses on the analysis and design of fractional filter with two cases. In the first case, the design and simulation of [Formula: see text] order low-pass Bessel filter has been done using MATLAB for [Formula: see text] value ranging from 0.1 to 0.9. SPICE simulation of 1.2, 1.5 and 1.9 order low-pass Bessel filter using fractional order capacitor of order [Formula: see text] with Tow–Thomas biquad have been performed. In the second case, low-pass ([Formula: see text] order Bessel filter has been simulated and designed using MATLAB, where [Formula: see text] and [Formula: see text] are two fractional order elements of a different order. SPICE simulation for different values of [Formula: see text] and [Formula: see text] have been done using two fractional order capacitors of [Formula: see text] and [Formula: see text] order with Tow–Thomas biquad.

Second Order Low Pass RC Active Filter for Low Frequency Signal Processing

The different parameters define the characteristics of filter for various applications like: Biomedical applications, Defense communication systems, Wireless Communication systems etc. The mostly measured parameters for filter designing are frequency range, cut off frequency, gain, power consumption, and noise. In this paper, our work focuses on frequency range measurement at cut off frequency of Hz of second order low pass filter with designed using CMOS technology for IC fabrication. The proposed circuit gives the high frequency range at low frequency (100Hz – 10MHz) with 1mV 50Hz low power supply using complementary compound pair on the value of R=1K and C=10pH. This second order active low pass filter provides high amplification at the output with 4.861V. It is implemented and simulated on 180nm Cadence tool in terms of wide frequency range or band at cut off frequency of Hz to MHz.

Effects of noises on near infrared sensor for blood glucose level measurement

This paper proposed the method of measuring glucose level in solution using near infrared light (NIR) and photodiode sensor. We studied noises that occurred on the output signal of NIR sensor in three different room conditions in order to know the effects on this sensor output voltage stability. The sensor’s circuit consisted of a 1450 nm NIR light emitting diode, a photodiode as the receiver, transimpedance amplifier, a notch filter, and a 4th order low pass filter. The results indicated that sunlight passing through windows was the most influencing factor caused the unstable sensor output voltage. Filters removed the effective voltages and the average sensor output voltages from the three rooms were 4.6825 V for air media, 2.2809 V for water media and 2.3368 V for glucose solution media. The output voltages tended to increase for one-hour measurement about 10 to 40 mV for air media, 40 to 90 mV for water media and 30 to 80 mV for glucose solution media. This sensor could only be used in a short time and suitable in a room without sunlight. Based on the voltage difference of the average sensor output voltage with water and glucose solution media, the sensor had the potential to be a blood glucose level meter.

Experimental validation of fractional order internal model controller design on buck and boost converter

In this paper, fractional order internal model control technique is formulated for non-ideal dc–dc buck and boost converter. The fractional order internal model control approach integrates the concept of Commande Robuste d’Ordre Non Entier principle for tuning a fractional order filter with internal model control scheme. The final controller can be expressed as a series combination of proportional integral derivative controller and a fractional order low pass filter. To assess the robustness of the proposed fractional order internal model control scheme, both the servo response and regulatory response of the dc–dc converters are investigated in the presence of disturbances. The efficacy of fractional order internal model control technique is demonstrated via comparison with 2 degrees of freedom internal model control scheme. Furthermore, an experimental validation of fractional order internal model control is conducted on laboratory setup, and a dSPACE 1104 microcontroller is used for hardware implementation. The simulation results and the hardware validation are a testimony to the effectiveness of fractional order internal model control technique.

Low pass anti-alias filter for ADC with differential input on base Op-Amp with differential output with a minimum number of capacitors

The new circuit of third order low-pass filter (LPF) on operational amplifier (Op-Amp) with differential output designed to limit the spectrum of signals at the input of an analog-to-digital converter (ADC) is presented. The developed circuit contains one capacitor less than in classical LPF. The basic equations of the new circuit are presented and the results of computer simulation obtained in Micro-Cap CAD, which based on models of THS4130 Op-Amp by Texas Instruments, are shown. The results of computer simulation confirm the efficiency of this LPF scheme and show a close to ideal correspondence between the theoretical and real amplitude-frequency response.

A highly efficient GHz switching GaN-based synchronous buck converter module

AbstractThe paper presents a highly efficient GaN-based synchronous buck converter suitable for switching in the lower GHz range. The module includes a very compact 2-stage GaN half-bridge converter MMIC (monolithic microwave integrated circuit) for low parasitic inductances between switches and drivers and a hybrid output network with core-less inductors to avoid ferrite losses. At 1 GHz switching frequency the buck converter achieves with pulse-width modulated (PWM) input signals power loop conversion efficiencies up to 78% for 40 V operation and output voltages up to 33 V. For 100 MHz the power loop efficiencies peak at 87.5% for 14.5 W conversion to 25 V. By changing the output network to a 2nd order low-pass with 700 MHz cut-off frequency the module has been characterized for the use as a supply modulator in very broadband envelope tracking systems with modulation bandwidths of up to 500 MHz. For 1 GHz switching frequency the power-added efficiency peaks at 74% for a 90% duty-cycle PWM input signal. The novelty of this work is that for the first time a buck converter design proves highest flexibility supporting different applications from very compact DC converters to microwave power amplifier efficiency enhancement techniques as well as efficient high frequency switching up to 1 GHz.

A Study on the Out-of-Step Detection Algorithm Using Time Variation of Complex Power-Part II: Out-of-Step Detection Algorithm and Simulation Results

One of the established unstable power swing (out-of-step) detection algorithms in micro grid/smart grid power systems uses a trajectory of apparent impedance in the R-X plane. However, this algorithm is not suitable for fast out-of-step conditions and it is hard to detect out-of-step conditions exactly. Another algorithm for out-of-step detection is using phasor measurement units (PMUs). However, PMUs need extra equipment. This paper presents the out-of-step detection algorithm using the trajectory of complex power. The trajectory of complex power and generator mechanical power is used to identify out-of-step conditions. A second order low pass digital filter is used to extract the generator mechanical power from the complex power. Variations of complex power are used to identify equilibrium points between stable and unstable conditions. The proposed out-of-step algorithm is based on the modification of assessment of a transient stability using equal area criterion (EAC). The proposed out-of-step algorithm is verified and tested by using alternative transient program/electromagnetic transient program (ATP/EMTP) MODELS.

Analysis of the ensemble of regression algorithms for the analog circuit parametric identification

Abstract The paper presents the application of the combined group of regression algorithms for the parameter identification of the analog circuit’s state. The fusion of regression machines is a new approach aimed at obtaining the high accuracy in the diagnosis of parametric faults determined in the presence of noise. The ensemble consists of multiple approaches, mainly based on variants of the linear regression techniques. Because the methods are simple, it is easier to build the accurate module than for the typical heuristic approach, such as Support Vector Machines (SVM). The methodology consists in preparing the ensemble architecture, selecting computational methods, optimizing features extracted from the diagnosed system and testing the module. It was tested on the 5th order lowpass filter and compared with the single regression algorithm, treated as the reference method. Obtained results show the usefulness of the proposed framework for the accurate identification of analog system parameters.