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.

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.

On a Design of Narrowband FIR Low-Pass Filters

2011 ◽  
pp. 2882-2887
Author(s):  
Gordana Jovanovic Dolecek ◽  
Javier Diaz Carmona
Keyword(s):  
Impulse Response ◽  
High Frequency ◽  
Digital Filters ◽  
Stop Band ◽  
Low Frequency ◽  
Pass Band ◽  
Low Pass ◽  
Frequency Components ◽  
Band Pass ◽  
High Pass

Stearns and David (1996) states that “for many diverse applications, information is now most conveniently recorded, transmitted, and stored in digital form, and as a result, digital signal processing (DSP) has become an exceptionally important modern tool.” Typical operation in DSP is digital filtering. Frequency selective digital filter is used to pass desired frequency components in a signal without distortion and to attenuate other frequency components (Smith, 2002; White, 2000). The pass-band is defined as the frequency range allowed to pass through the filter. The frequency band that lies within the filter stop-band is blocked by the filter and therefore eliminated from the output signal. The range of frequencies between the pass-band and the stop-band is called the transition band and for this region no filter specification is given. Digital filters can be characterized either in terms of the frequency response or the impulse response (Diniz, da Silva & Netto, 2002). Depending on its frequency characteristic, a digital filter is either low-pass, high-pass, band-pass, or band-stop filters. A low-pass (LP) filter passes low frequency components to the output, while eliminating high-frequency components. Conversely, the high-pass (HP) filter passes all high-frequency components and rejects all low-frequency components. The band-pass (BP) filter blocks both low- and high-frequency components while passing the intermediate range. The band-stop (BS) filter eliminates the intermediate band of frequencies while passing both low- and high-frequency components. In terms of their impulse responses digital filters are either infinite impulse response (IIR) or finite impulse response (FIR) digital filters. Each of four types of filters (LP, HP, BP, and BS) can be designed as an FIR or an IIR filter (Ifeachor & Jervis, 2001; Mitra, 2005; Oppenheim & Schafer, 1999).

Weaknesses of the Baxter-King Filter: Is a Pattern-Based Filter an Alternative? / Schwächen des Baxter-King Filters: Ist ein musterbasierter Filter eine Alternative?

2005 ◽  
Vol 225 (4) ◽  
Author(s):  
Georg Goldrian
Keyword(s):  
Time Series ◽  
High Frequency ◽  
Degree Of Approximation ◽  
Trigonometric Function ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Frequency Components ◽  
Slow Moving ◽  
Ideal Filter

SummaryThe Baxter-King filter shows some weaknesses, particularly with regard to monthly time series. This procedure involves not only a loss of data for the border areas of time series, but suppresses inadequately high frequency components and shows as a low-pass filter only the performance of ordinary moving averages. Another important finding is that the maximal lag Κ not only determines the degree of approximation to an ideal filter, as Baxter and King argue, but also the ability to extract a slow moving component. A pattern-based filter, whose weights are generated by a trigonometric function as well, does not possess such weaknesses, and is thus a real alternative to the Baxter-King filter.

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 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.

Aliasing Effects on Nodal Acceleration Output From Nonlinear Finite Element Simulations

2000 ◽  
Author(s):  
Mark O. Neal ◽  
Chin-Hsu Lin ◽  
J. T. Wang
Keyword(s):  
Finite Element ◽  
High Frequency ◽  
Nonlinear Finite Element ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Frequency Components ◽  
Averaging Filter ◽  
Very High ◽  
Acceleration Output

Abstract Nodal acceleration output from nonlinear finite element crash simulations often contains high frequency components. If this output is not sampled frequently enough the high frequency components will be aliased and the resulting acceleration output will be inaccurate. It is recommended in this paper that a low-pass filter be installed in the crashworthiness finite element codes which would remove the high frequency components of the nodal accelerations before they are sampled for output. This would completely eliminate aliasing error in acceleration output. Prior to this installation, there are several options for reducing the effects of aliasing on acceleration output. One option is to request very high sampling rates for acceleration output; however this will result in very large output files. Another option is to calculate the accelerations by differentiating the output velocities. This option, which effectively is an averaging filter acting on the accelerations, is available in the finite element code DYNA3D. The properties of this filter are examined in this paper and it is shown that this filter is very effective in reducing the effects of aliasing on acceleration output, although it should not be expected to completely eliminate potential aliasing problems. Finally, guidelines are presented for selecting nodes and sampling rates based on local natural frequencies that will reduce the effect of aliasing of the acceleration output.

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.

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