The implementation and characteristics of a compact lumped-element three-order low pass filter are presented in this paper. The filter with 120 MHz cut off frequency, as well as more than 20 dB of the attenuation abov...The implementation and characteristics of a compact lumped-element three-order low pass filter are presented in this paper. The filter with 120 MHz cut off frequency, as well as more than 20 dB of the attenuation above 360 MHz frequency band is successfully manufactured in an LTCC substrate with 40 pm layer thickness. The overall size of the filter is 2.0 mm×1.2 mm×0.9 mm. A good coincidence between the measured results and the full-wave electromagnetic designed responses is observed.展开更多
Background Genotype-by-sequencing has been proposed as an alternative to SNP genotyping arrays in genomic selection to obtain a high density of markers along the genome.It requires a low sequencing depth to be cost ef...Background Genotype-by-sequencing has been proposed as an alternative to SNP genotyping arrays in genomic selection to obtain a high density of markers along the genome.It requires a low sequencing depth to be cost effective,which may increase the error at the genotype assigment.Third generation nanopore sequencing technology offers low cost sequencing and the possibility to detect genome methylation,which provides added value to genotype-by-sequencing.The aim of this study was to evaluate the performance of genotype-by-low pass nanopore sequencing for estimating the direct genomic value in dairy cattle,and the possibility to obtain methylation marks simultaneously.Results Latest nanopore chemistry(LSK14 and Q20)achieved a modal base calling accuracy of 99.55%,whereas previous kit(LSK109)achieved slightly lower accuracy(99.1%).The direct genomic value accuracy from genotype-by-low pass sequencing ranged between 0.79 and 0.99,depending on the trait(milk,fat or protein yield),with a sequencing depth as low as 2×and using the latest chemistry(LSK114).Lower sequencing depth led to biased estimates,yet with high rank correlations.The LSK109 and Q20 achieved lower accuracies(0.57-0.93).More than one million high reliable methylated sites were obtained,even at low sequencing depth,located mainly in distal intergenic(87%)and promoter(5%)regions.Conclusions This study showed that the latest nanopore technology in useful in a LowPass sequencing framework to estimate direct genomic values with high reliability.It may provide advantages in populations with no available SNP chip,or when a large density of markers with a wide range of allele frequencies is needed.In addition,low pass sequencing provided nucleotide methylation status of>1 million nucleotides at≥10×,which is an added value for epigenetic studies.展开更多
This paper highlights the memristor bridge-based lowpass filter (LPF) and improved image processing algorithms along with a novel adaptive Gaussian filter for denoising image and a new Gaussian pyramid for scale invar...This paper highlights the memristor bridge-based lowpass filter (LPF) and improved image processing algorithms along with a novel adaptive Gaussian filter for denoising image and a new Gaussian pyramid for scale invariant feature transform (SIFT). First, a novel kind of LPF based on the memristor bridge is designed, whose cut-off frequency and other traits are demonstrated to change with different time and memristance. In light of the changeable parameter of the memristor bridge-based LPF, a new adaptive Gaussian filter and an improved SIFT algorithm are presented. Finally, experiment results show that the peak signalto- noise ratio (PSNR) of our denoising is bettered more than 2.77 dB compared to the corresponding of the traditional Gaussian filter, and our improved SIFT performances including the number of matched feature points and the percent of correct matches are higher than the traditional SIFT, which verifies feasibility and effectiveness of our algorithm.展开更多
A new technique using signal flow graph for conversion of ladder based filter into CFOA based filter has been proposed. The proposed technique converts the existing LC ladder based filter into CFOA in low pass and hig...A new technique using signal flow graph for conversion of ladder based filter into CFOA based filter has been proposed. The proposed technique converts the existing LC ladder based filter into CFOA in low pass and high pass configuration. The design of low pass filter and high pass filter has been realized using the proposed technique. The proposed configuration is implemented using CFOA as an active device and all the capacitors are grounded. Simulation has been carried out using simulation software I-cap. The simulation results have been demonstrated and discussed.展开更多
An effective technique to design compact low pass filter has been proposed in this paper. The proposed method is highly effective for L-band applications. Low impedance microstrip lines are arranged such that they wor...An effective technique to design compact low pass filter has been proposed in this paper. The proposed method is highly effective for L-band applications. Low impedance microstrip lines are arranged such that they work as open stubs to increase the selectivity of the filter. Using the proposed technique about 57% size reduction has been realized with sharper roll off characteristics. An empirical expression is derived to determine the dimension of resonators. For cut-off frequency of 1.7 GHz the investigated method has been fabricated and tested. There is a close agreement be-tween simulated and measured展开更多
In this paper the low pass filter is discussed in the noisy case. And a regularized low pass filter is presented. The convergence property of the regularized low pass filtering algorithm is proved in theory and tested...In this paper the low pass filter is discussed in the noisy case. And a regularized low pass filter is presented. The convergence property of the regularized low pass filtering algorithm is proved in theory and tested by numerical results.展开更多
Digital filters play a key role in the field of digital signal processing. This paper presents a linear phase digital low pass finite impulse response (FIR) filter design using particle swarm optimization and its two ...Digital filters play a key role in the field of digital signal processing. This paper presents a linear phase digital low pass finite impulse response (FIR) filter design using particle swarm optimization and its two new variants, dynamic and adjustable particle swarm optimization (DAPSO) and particle swarm optimization with variable acceleration factor (PSO-VAF) and illustrates the superiority of the PSO-VAF method over PSO based methods. Two fitness functions are considered. The fitness1 is used to find the possible minimum ripples in pass band and stop band in case of PSO, DAPSO and PSO-VAF. Fitness2 is able to control the ripples in both bands separately. A comparison of simulation results demonstrates the performance of PSO and its methods in designing digital low pass FIR filters.展开更多
Non equiripple approximation of filter characteristics can be realized either odd order or even order in the symmetric load case.This paper presents a method of synthesizing non equiripple low pass filter based on ...Non equiripple approximation of filter characteristics can be realized either odd order or even order in the symmetric load case.This paper presents a method of synthesizing non equiripple low pass filter based on iteration analysis,in which the rational fraction formed of Chebyshev polynomial is used as the filter characteristic function.This method is convenient for computer programming,because the attenuation zeros and poles of the filter can be determined easily and the synthesis procedure is simple,too.The given examples show that the method is of a practical value in filter design.展开更多
This paper presents a novel low-pass filter （LPF） with sharp rejection, wide stopband and compact size, which are realized by the defected ground structure （DGS） and the defected microstrip structure （DMS）. The ...This paper presents a novel low-pass filter （LPF） with sharp rejection, wide stopband and compact size, which are realized by the defected ground structure （DGS） and the defected microstrip structure （DMS）. The equivalent circuit model is proposed and the circuit parameters are extracted by the circuit simulation software. The parameters measured are 3 dB cutoff frequency fc of 5.2 GHz, the insertion loss less than 0.5 dB from DC to 4.0 GHz and S21 less than -20 dB within the wide stopband from 6 GHz to 16 GHz. The results of the circuit optimization agree well with those of the full wave simulation and the measured ones, which validate the effectiveness of the equivalent circuit model. The size of the proposed LPF is decreased compared with normal LPF. This LPF can be applied in rectennas to eliminate high order harmonics.展开更多
A novel defected ground structure （DGS） for the microstrip line is proposed in this paper. The DGS lattice has more defect parameters so that it can provide better performance than the conventional dumbbell-shaped D...A novel defected ground structure （DGS） for the microstrip line is proposed in this paper. The DGS lattice has more defect parameters so that it can provide better performance than the conventional dumbbell-shaped DGS. Selectivity is improved by 97.2% with a sharpness factor of 24.6%. The method is applied to the design of a low-pass filter to confirm validity of the proposed DGS.展开更多
In this paper the design and implementation of sixth-order lowpass elliptic switched-capacitor filter( SCF) for interface circuit of Micro-Electro-Mechanical System( MEMS) sensor are presented. This work aims to lower...In this paper the design and implementation of sixth-order lowpass elliptic switched-capacitor filter( SCF) for interface circuit of Micro-Electro-Mechanical System( MEMS) sensor are presented. This work aims to lower total harmonic distortion( THD) without deteriorating other performances. After system design in Simulink,the filter is realized in transistor level and finally fabricated in Central Semiconductor Manufacturing Corporation( CSMC) 0.5 μm metal-oxide-semiconductor( CMOS) technology. Typical measured results are: it operates with 25: 1 clock-to-corner frequency ratio and a 10 k Hz maximum corner frequency. The maximum passband ripple is about 0.49 d B and the minimum stopband rejection is 40 d B for the temperature from-20 ℃to 80 ℃. For the 250 k Hz clock frequency setting,given the 1 k Hz,- 8 d BVrms input signal,the measured worst case THD is-64 d B. The active area of the chip is 2.8 mm2 with 8 pads. The analog power dissipation is10 m W from a 5 V power supply.展开更多
It is a time-consuming and often iterative procedure to determine design parameters based on fine, accurate but expensive, models. To decrease the number of fine model evaluations, space mapping techniques may be empl...It is a time-consuming and often iterative procedure to determine design parameters based on fine, accurate but expensive, models. To decrease the number of fine model evaluations, space mapping techniques may be employed. In this approach, it is assumed both fine model and coarse, fast but inaccurate, one are available. First, the coarse model is optimized to obtain design parameters satisfying design objectives. Next, auxiliary parameters are calibrated to match coarse and fine models’ responses. Then, the improved coarse model is re-optimized to obtain new design parameters. The design procedure is stopped when a satisfactory solution is reached. In this paper, an implicit space mapping method is used to design a microstrip low-pass elliptic filter. Simulation results show that only two fine model evaluations are sufficient to get satisfactory results.展开更多
Complimentary hexagonal-omega structures are used to design compact, low insertion loss (IL), low pass filter with sharp cut-off. It has been designed for improvement of roll-off performance based on both μ and ε ne...Complimentary hexagonal-omega structures are used to design compact, low insertion loss (IL), low pass filter with sharp cut-off. It has been designed for improvement of roll-off performance based on both μ and ε negative property of the complimentary hex-omega structure while maintaining the filter pass-band performance. By properly designing and loading the hexagonal-omega structure in the ground of microstrip line not only improve the roll-off of the low pass filter, but also reduced the filter size. The simulated results indicate that the proposed filter achieves a flat pass band with no ripples as well as selectivity of 19.68 dB/GHz, corresponding to 5-unit cells hex-omega structures. This significantly exceeds the 5.6 dB/GHz selectivity of the conventional low pass filter design, due to sub-lambda dimensions of the hex-omega structure. A prototype filter implementing area is: 0.712λg x 0.263λg, λg being the guided wavelength at 3-dB cut-off frequency (fc). The proposed filter has a size smaller by 36.2%.展开更多
The influence of soaking temperature on microstructure of high temperature multi-pass compression deformation for two low carbon steels(steel A:wC=0.032%and wMn=0.25%;steel B:wC=0.165%and wMn=0.38%)is studied on the t...The influence of soaking temperature on microstructure of high temperature multi-pass compression deformation for two low carbon steels(steel A:wC=0.032%and wMn=0.25%;steel B:wC=0.165%and wMn=0.38%)is studied on the thermal-mechanical simulator in order to rationalize the hot-rolling schedule of low-carbon steel and to promote the low-temperature heating technology.The results show that the microstructures of steel A are almost not affected by reducing soaking temperature,but the acicular ferrite forms in steel B when the soaking temperature is reduced from 1 200 to 1170℃,due to its smaller initial austenite grain size according to recrystallization kinetics theory.展开更多
基金This work was supported by the National Nature Science Foundation of China under Grant No. 60425102.
文摘The implementation and characteristics of a compact lumped-element three-order low pass filter are presented in this paper. The filter with 120 MHz cut off frequency, as well as more than 20 dB of the attenuation above 360 MHz frequency band is successfully manufactured in an LTCC substrate with 40 pm layer thickness. The overall size of the filter is 2.0 mm×1.2 mm×0.9 mm. A good coincidence between the measured results and the full-wave electromagnetic designed responses is observed.
文摘Background Genotype-by-sequencing has been proposed as an alternative to SNP genotyping arrays in genomic selection to obtain a high density of markers along the genome.It requires a low sequencing depth to be cost effective,which may increase the error at the genotype assigment.Third generation nanopore sequencing technology offers low cost sequencing and the possibility to detect genome methylation,which provides added value to genotype-by-sequencing.The aim of this study was to evaluate the performance of genotype-by-low pass nanopore sequencing for estimating the direct genomic value in dairy cattle,and the possibility to obtain methylation marks simultaneously.Results Latest nanopore chemistry(LSK14 and Q20)achieved a modal base calling accuracy of 99.55%,whereas previous kit(LSK109)achieved slightly lower accuracy(99.1%).The direct genomic value accuracy from genotype-by-low pass sequencing ranged between 0.79 and 0.99,depending on the trait(milk,fat or protein yield),with a sequencing depth as low as 2×and using the latest chemistry(LSK114).Lower sequencing depth led to biased estimates,yet with high rank correlations.The LSK109 and Q20 achieved lower accuracies(0.57-0.93).More than one million high reliable methylated sites were obtained,even at low sequencing depth,located mainly in distal intergenic(87%)and promoter(5%)regions.Conclusions This study showed that the latest nanopore technology in useful in a LowPass sequencing framework to estimate direct genomic values with high reliability.It may provide advantages in populations with no available SNP chip,or when a large density of markers with a wide range of allele frequencies is needed.In addition,low pass sequencing provided nucleotide methylation status of>1 million nucleotides at≥10×,which is an added value for epigenetic studies.
基金supported by the National Natural Science Foundation of China(61550110248)
文摘This paper highlights the memristor bridge-based lowpass filter (LPF) and improved image processing algorithms along with a novel adaptive Gaussian filter for denoising image and a new Gaussian pyramid for scale invariant feature transform (SIFT). First, a novel kind of LPF based on the memristor bridge is designed, whose cut-off frequency and other traits are demonstrated to change with different time and memristance. In light of the changeable parameter of the memristor bridge-based LPF, a new adaptive Gaussian filter and an improved SIFT algorithm are presented. Finally, experiment results show that the peak signalto- noise ratio (PSNR) of our denoising is bettered more than 2.77 dB compared to the corresponding of the traditional Gaussian filter, and our improved SIFT performances including the number of matched feature points and the percent of correct matches are higher than the traditional SIFT, which verifies feasibility and effectiveness of our algorithm.
文摘A new technique using signal flow graph for conversion of ladder based filter into CFOA based filter has been proposed. The proposed technique converts the existing LC ladder based filter into CFOA in low pass and high pass configuration. The design of low pass filter and high pass filter has been realized using the proposed technique. The proposed configuration is implemented using CFOA as an active device and all the capacitors are grounded. Simulation has been carried out using simulation software I-cap. The simulation results have been demonstrated and discussed.
文摘An effective technique to design compact low pass filter has been proposed in this paper. The proposed method is highly effective for L-band applications. Low impedance microstrip lines are arranged such that they work as open stubs to increase the selectivity of the filter. Using the proposed technique about 57% size reduction has been realized with sharper roll off characteristics. An empirical expression is derived to determine the dimension of resonators. For cut-off frequency of 1.7 GHz the investigated method has been fabricated and tested. There is a close agreement be-tween simulated and measured
文摘In this paper the low pass filter is discussed in the noisy case. And a regularized low pass filter is presented. The convergence property of the regularized low pass filtering algorithm is proved in theory and tested by numerical results.
文摘Digital filters play a key role in the field of digital signal processing. This paper presents a linear phase digital low pass finite impulse response (FIR) filter design using particle swarm optimization and its two new variants, dynamic and adjustable particle swarm optimization (DAPSO) and particle swarm optimization with variable acceleration factor (PSO-VAF) and illustrates the superiority of the PSO-VAF method over PSO based methods. Two fitness functions are considered. The fitness1 is used to find the possible minimum ripples in pass band and stop band in case of PSO, DAPSO and PSO-VAF. Fitness2 is able to control the ripples in both bands separately. A comparison of simulation results demonstrates the performance of PSO and its methods in designing digital low pass FIR filters.
文摘Non equiripple approximation of filter characteristics can be realized either odd order or even order in the symmetric load case.This paper presents a method of synthesizing non equiripple low pass filter based on iteration analysis,in which the rational fraction formed of Chebyshev polynomial is used as the filter characteristic function.This method is convenient for computer programming,because the attenuation zeros and poles of the filter can be determined easily and the synthesis procedure is simple,too.The given examples show that the method is of a practical value in filter design.
文摘This paper presents a novel low-pass filter （LPF） with sharp rejection, wide stopband and compact size, which are realized by the defected ground structure （DGS） and the defected microstrip structure （DMS）. The equivalent circuit model is proposed and the circuit parameters are extracted by the circuit simulation software. The parameters measured are 3 dB cutoff frequency fc of 5.2 GHz, the insertion loss less than 0.5 dB from DC to 4.0 GHz and S21 less than -20 dB within the wide stopband from 6 GHz to 16 GHz. The results of the circuit optimization agree well with those of the full wave simulation and the measured ones, which validate the effectiveness of the equivalent circuit model. The size of the proposed LPF is decreased compared with normal LPF. This LPF can be applied in rectennas to eliminate high order harmonics.
基金Project supported by the Shanghai Leading Academic Discipline Project (Grant No.T0102)
文摘A novel defected ground structure （DGS） for the microstrip line is proposed in this paper. The DGS lattice has more defect parameters so that it can provide better performance than the conventional dumbbell-shaped DGS. Selectivity is improved by 97.2% with a sharpness factor of 24.6%. The method is applied to the design of a low-pass filter to confirm validity of the proposed DGS.
基金Sponsored by the Fundamental Research Funds for the Central Universities(Grant No.HIT.NSRIF.2013040)
文摘In this paper the design and implementation of sixth-order lowpass elliptic switched-capacitor filter( SCF) for interface circuit of Micro-Electro-Mechanical System( MEMS) sensor are presented. This work aims to lower total harmonic distortion( THD) without deteriorating other performances. After system design in Simulink,the filter is realized in transistor level and finally fabricated in Central Semiconductor Manufacturing Corporation( CSMC) 0.5 μm metal-oxide-semiconductor( CMOS) technology. Typical measured results are: it operates with 25: 1 clock-to-corner frequency ratio and a 10 k Hz maximum corner frequency. The maximum passband ripple is about 0.49 d B and the minimum stopband rejection is 40 d B for the temperature from-20 ℃to 80 ℃. For the 250 k Hz clock frequency setting,given the 1 k Hz,- 8 d BVrms input signal,the measured worst case THD is-64 d B. The active area of the chip is 2.8 mm2 with 8 pads. The analog power dissipation is10 m W from a 5 V power supply.
文摘It is a time-consuming and often iterative procedure to determine design parameters based on fine, accurate but expensive, models. To decrease the number of fine model evaluations, space mapping techniques may be employed. In this approach, it is assumed both fine model and coarse, fast but inaccurate, one are available. First, the coarse model is optimized to obtain design parameters satisfying design objectives. Next, auxiliary parameters are calibrated to match coarse and fine models’ responses. Then, the improved coarse model is re-optimized to obtain new design parameters. The design procedure is stopped when a satisfactory solution is reached. In this paper, an implicit space mapping method is used to design a microstrip low-pass elliptic filter. Simulation results show that only two fine model evaluations are sufficient to get satisfactory results.
文摘Complimentary hexagonal-omega structures are used to design compact, low insertion loss (IL), low pass filter with sharp cut-off. It has been designed for improvement of roll-off performance based on both μ and ε negative property of the complimentary hex-omega structure while maintaining the filter pass-band performance. By properly designing and loading the hexagonal-omega structure in the ground of microstrip line not only improve the roll-off of the low pass filter, but also reduced the filter size. The simulated results indicate that the proposed filter achieves a flat pass band with no ripples as well as selectivity of 19.68 dB/GHz, corresponding to 5-unit cells hex-omega structures. This significantly exceeds the 5.6 dB/GHz selectivity of the conventional low pass filter design, due to sub-lambda dimensions of the hex-omega structure. A prototype filter implementing area is: 0.712λg x 0.263λg, λg being the guided wavelength at 3-dB cut-off frequency (fc). The proposed filter has a size smaller by 36.2%.
基金the National Natural Science Foundation of China(Nos.50971137 and 50934011)
文摘The influence of soaking temperature on microstructure of high temperature multi-pass compression deformation for two low carbon steels(steel A:wC=0.032%and wMn=0.25%;steel B:wC=0.165%and wMn=0.38%)is studied on the thermal-mechanical simulator in order to rationalize the hot-rolling schedule of low-carbon steel and to promote the low-temperature heating technology.The results show that the microstructures of steel A are almost not affected by reducing soaking temperature,but the acicular ferrite forms in steel B when the soaking temperature is reduced from 1 200 to 1170℃,due to its smaller initial austenite grain size according to recrystallization kinetics theory.
