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.

Fractional Order Capacitor in First-Order and Second-Order Filter

2020 ◽  
Vol 12 (1) ◽  
pp. 75-78
Author(s):  
Kanchan Sengar ◽  
Arun Kumar
Keyword(s):  
Fractional Order ◽  
Second Order ◽  
Active Filters ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Order Filter ◽  
Low Pass ◽  
Band Pass ◽  
High Pass

Background: Fractional order Butterworth and Chebyshev (low-pass filter circuits, highpass filter circuits and band-pass filters circuits) types of first and second order filter circuits have been simulated and their transfer function are derived. The effect of change of the fractional order α on the behavior of the circuits is investigated. Objective: This paper presents the use of fractional order capacitor in active filters. The expressions for the magnitude, phase, the quality factor, the right-phase frequencies, and the half power frequencies are derived and compared with their previous counterpart. Methods: The circuits have been simulated using Orcad as well as MATLAB for the different value of α. We have developed the fractional gain and phase equations for low pass filter circuits, high pass filter circuits and band pass filter circuits in Sallen-Key topology. Results: It is observed that the bandwidth increases significantly with fractional order other than unity for the low pass as well as high pass and band pass filters. Conclusion: We have also seen that in the frequency domain, the magnitude and phase plots in the stop band change nearly linearly with the fractional order. If we compare the fractional Butterworth filters for low-pass and high-pass type with conventional filters then we find that the roll-off rate is equal to the next higher order filter.

Novel Low-Pass Microwave Filter Based on Rectangular Ring DGS

2013 ◽  
Vol 273 ◽  
pp. 371-374
Author(s):  
Bao Ping Li ◽  
Yan Liang Zhang
Keyword(s):  
Stop Band ◽  
Center Frequency ◽  
Pass Band ◽  
Band Pass Filter ◽  
Defected Ground Structure ◽  
Ground Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Compact Size ◽  
Low Pass

Due to the frequency response periodicity of distributed transmission line, microstrip band-pass filter usually produces parasitic pass-band and outputs harmonics away from the center frequency of main pass-band. Based on the study of rectangular ring defected ground structure, a 5-order microstrip LPF(low-pass filter) was designed using the single-pole band-stop and slow-wave characteristics of the rectangular ring DGS(Defected Ground Structure) and SISS(Step-Impedance Shunt Stub) structure. Compared with traditional LPF, this LPF presents the advantages of compact size, low insertion loss, broad stop-band and high steep. It also validates the requirements of miniaturization and high performance for filters.

Design and Simulation of Switched Capacitor Filter for Speed Change Parameter Converter

2013 ◽  
Vol 562-565 ◽  
pp. 1132-1136
Author(s):  
Xiao Wei Liu ◽  
Jian Yang ◽  
Song Chen ◽  
Liang Liu ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Stop Band ◽  
Cutoff Frequency ◽  
Rapid Change ◽  
Pass Band ◽  
Cmos Process ◽  
Switched Capacitor ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
The Time Domain

In this paper, we design a high-order switched capacitor filter for rapid change parameter converter. This design uses a structure which consists of three biquads filter sub-units. The design is a 6th-order SC elliptic low-pass filter, and the sample frequency is 250 kHz. By the MATLAB Simulink simulation, the system can meet the design requirements in the time domain. In this paper, the 6th-order switched capacitor elliptic low-pass filter was implemented under 0.5 um CMOS process and simulated in Cadence. The final simulation results show that the pass-band cutoff frequency is 10 kHz, and the maximum pass-band ripple is about 0.106 dB. The stop-band cutoff frequency is 20 kHz, and the minimum stop-band attenuation is 74.78 dB.

A Low Pass Filter Based on Spoof Surface Plasma Polaritons

2017 ◽  
Vol 744 ◽  
pp. 428-432
Author(s):  
Zhi Wei Zeng ◽  
Ming Zhe Hu ◽  
Jing Li Long ◽  
Deng Hui Ji ◽  
Yue Yin
Keyword(s):  
Stop Band ◽  
Base Station ◽  
Pass Band ◽  
Surface Plasma ◽  
Pass Filter ◽  
Low Pass Filter ◽  
The Third ◽  
Low Pass ◽  
New Type ◽  
Section Structure

A low pass filter based on spoof surface plasma polaritons (SSPPs) was devised successfully, which possessed three-section structure, the microstrip wave guide as the first section, the conversion section as the second section, and the SSPPs as the third section. It should be noted that there is a new V-shaped groove structure in the third section, which were carried out by the simulation on characteristics of stop band rejection characteristic and bandwidth for low pass filter. These results indicated that the low pass filter had Pass-band between direct-current and 7.8592GHz, the pass-band insertion loss was better than -3dB, the pass-band reflection was less than -10dB. This new type of SSPPs low pass filter would be certain engineering value in the application of microstrip circuit, microwave base station and radar microwave communication system between L band and X band.

A modified Bessel filter for amplitude demodulation of respiratory electromyograms

1998 ◽  
Vol 84 (1) ◽  
pp. 378-388 ◽  
Author(s):  
Ronald S. Platt ◽  
Eric A. Hajduk ◽  
Manuel Hulliger ◽  
Paul A. Easton
Keyword(s):  
High Frequency ◽  
Stop Band ◽  
Pass Band ◽  
Third Order ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Transient Characteristics ◽  
Low Pass ◽  
Seventh Order ◽  
Frequency Components

Platt, Ronald S., Eric A. Hajduk, Manuel Hulliger, and Paul A. Easton. A modified Bessel filter for amplitude demodulation of respiratory electromyograms. J. Appl. Physiol. 84(1): 378–388, 1998.—We studied a device that is commonly used for amplitude demodulation of respiratory muscle electromyograms (EMG). This device contains a rectifier and a low-pass filter called a modified third-order Paynter filter. We characterized this filter and found that it has good transient characteristics that suit its task as an EMG demodulator, but it has poor high-frequency attenuation that passes interfering, higher frequency components to the output waveform. Therefore, we designed and constructed a new filter with transient characteristics that are comparable to those of the modified Paynter filter but with superior high-frequency attenuation. This new filter is a modified seventh-order Bessel filter. We also identified a simple technique to convert an existing modified Paynter filter back to an original Paynter filter. The original Paynter filter has a wider pass band than the modified Paynter filter but superior stop-band attenuation.

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 High-Performance Low-Pass Filter Using Stepped Impedance Resonator and Defected Ground Structure

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 403 ◽  
Author(s):  
Jin Zhang ◽  
Ruosong Yang ◽  
Chen Zhang
Keyword(s):  
High Performance ◽  
Stop Band ◽  
Pass Band ◽  
Defected Ground Structure ◽  
Ground Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Stepped Impedance Resonator ◽  
Internal Coupling

A microstrip low-pass filter (LPF) using reformative stepped impedance resonator (SIR) and defected ground structure (DGS) is proposed in this paper. The proposed filter not only possesses the advantage of high frequency selectivity of SIR hairpin LPF with internal coupling, but also possesses the large stop-band (SB) bandwidth by adjusting the number and area of DGS units. The LPF proposed in this paper possesses the properties of miniaturization, wide SB, high selectivity, and low pass-band ripple (PBR) simultaneously. The characteristic parameters of the proposed LPF is that: the pass-band (PB) is 0~2 GHz, the PBR is 0.5 dB, the SB range is from 2.4 GHz to 9 GHz when the attenuation is under 20 dB, and the maximal attenuation could reach 45 dB in the SB. The size of this proposed LPF is 0.13 λ × 0.09 λ ; λ is the corresponding wavelength of the upper PB edge frequency of 2 GHz.

scholarly journals Improvement in Cutoff Frequency of Microstrip Butterworth Low Pass Filter using DGS Technique

2019 ◽  
Vol 9 (2) ◽  
pp. 1121-1124
Keyword(s):  
Stop Band ◽  
Cutoff Frequency ◽  
Ground Surface ◽  
Pass Band ◽  
Defected Ground Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Compact Size ◽  
Low Pass ◽  
Sharp Rejection

This paper presents the design, analysis and fabrication of Butterworth Low pass filter with sharp rejection response using defected ground surface technique. The work is carried out to design a low pass filter with cut-off frequency 2.5 GHz to achieved the broad frequency response; the first step is to make a rectangle of 10x10mm at ground surface and the equivalent circuit for the DGS, subsequently followed to consequent L-C parameters extraction using analysis of S parameters response (EM simulation). The designed Butterworth low pass filter is realized and optimized using DGS (Defected Ground Structure) to attain a compact size, satisfactory transition sharpness along with low insertion loss in pass band and wide rejection in the stop band. The fabricated device showed the good conformity with theoretical and VNA measured result.

A Low Power Low-Pass Fourth-Order Filter for WiMAX/LTE Receiver in CMOS 45nm Technology

2016 ◽  
Vol 26 (03) ◽  
pp. 1750048 ◽  
Author(s):  
Vida Orduee Niar ◽  
Gholamreza Zare Fatin
Keyword(s):  
Low Power ◽  
Fourth Order ◽  
Supply Voltage ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Power Filter ◽  
Order Filter ◽  
Source Follower ◽  
Low Pass ◽  
Circuit Technique

In this paper, a [Formula: see text]-[Formula: see text] low-pass and low power filter with tunable in-band attenuation for WiMAX/LTE receiver is presented. The fourth-order filter consists of two cascaded biquad stages. The source-follower (SF) stage is used as a key building block in these biquads. In this paper, we have presented a circuit technique to reduce the nonlinearity of the SF stage resulting from unmatched signal swings at the gate and source terminals of the input transistor. The proposed SF stage, is used for design of a linear biquad which is then utilized in a fourth-order Butterworth low-pass filter. The simulation results of the filter for bandwidth of 10 MHz show that the IIP3 of the filter is equal to 8.22[Formula: see text]dBm, in-band noise density is 100[Formula: see text]nV/[Formula: see text]Hz and power consumption is 5.9[Formula: see text]mW. The supply voltage of the filter is equal to 1[Formula: see text]V.

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