A novel particle filter bandwidth adaption for kernel particle filter （BAKPF） is proposed. Selection of the kernel bandwidth is a critical issue in kernel density estimation （KDE）. The plug-in method is adopted to...A novel particle filter bandwidth adaption for kernel particle filter （BAKPF） is proposed. Selection of the kernel bandwidth is a critical issue in kernel density estimation （KDE）. The plug-in method is adopted to get the global fixed bandwidth by optimizing the asymptotic mean integrated squared error （AMISE） firstly. Then, particle-driven bandwidth selection is invoked in the KDE. To get a more effective allocation of the particles, the KDE with adap- tive bandwidth in the BAKPF is used to approximate the posterior probability density function （PDF） by moving particles toward the posterior. A closed-form expression of the true distribution is given. The simulation results show that the proposed BAKPF performs better than the standard particle filter （PF）, unscented particle filter （UPF） and the kernel particle filter （KPF） both in efficiency and estimation precision.展开更多
A novel elliptical patch resonator for a compact bandpass filter with tunable bandwidth is presented. This bandpass filter has the advantage of great flexibility in which the center frequency can be changed easily. Th...A novel elliptical patch resonator for a compact bandpass filter with tunable bandwidth is presented. This bandpass filter has the advantage of great flexibility in which the center frequency can be changed easily. The bandwidth of this filter can be modified by simply changing one variable, and this makes the proposed design unique. The order of the elliptical patch resonator can be increased, and three types of different orders of the same design are compared. The proposed filter can be used for future compact advanced wireless communication systems.展开更多
Aiming at the large cost of calculating variable bandwidth kernel particle filter and the high complexity of its algorithm,a self-adjusting kernel function particle filter is presented. Kernel density estimation is fa...Aiming at the large cost of calculating variable bandwidth kernel particle filter and the high complexity of its algorithm,a self-adjusting kernel function particle filter is presented. Kernel density estimation is facilitated to iterate and obtain new particle set. And the standard deviation of particle is introduced in the kernel bandwidth. According to the characteristics of particle distribution,the bandwidth is dynamically adjusted,and the particle distribution can thus be more close to the posterior probability density model of the system. Meanwhile,the kernel density is used to estimate the weight of updating particle and the system state. The simulation results show the feasibility and effectiveness of the proposed algorithm.展开更多
In software defined radio (SDR), sharp filters of different bandwidth are required to fine tune the desired channel. This requires different computational resources and large number of filter coefficients. This paper ...In software defined radio (SDR), sharp filters of different bandwidth are required to fine tune the desired channel. This requires different computational resources and large number of filter coefficients. This paper proposes a continuously variable bandwidth sharp finite impulse response (FIR) filter with low distortion and low complexity. For this, a fixed length FIR filter is used with two arbitrary sampling rate converters. This system can be used for both the continuous increase as well as decrease of the effective bandwidth of a filter. The low complexity and sharpness are achieved by using the frequency-response masking (FRM) approach for the design of the fixed length FIR filter. The sharp transition width leads to maximum rejection to channel interference in SDR.展开更多
Most existing reconstruction algorithms for photoacoustic imaging (PAI) assume that transducers used to receive ultrasound signals have infinite bandwidth. When transducers with finite bandwidth are used, this assumpt...Most existing reconstruction algorithms for photoacoustic imaging (PAI) assume that transducers used to receive ultrasound signals have infinite bandwidth. When transducers with finite bandwidth are used, this assumption may result in reduction of the imaging contrast and distortions of reconstructed images. In this paper, we propose a novel method to compensate the finite bandwidth effect in PAI by using an optimal filter in the Fourier domain. Simulation results demonstrate that the use of this method can improve the contrast of the reconstructed images with finite-bandwidth ultrasound transducers.展开更多
This paper proposes third order tunable bandwidth active Switched-Capacitor filter. The circuit consists of only op-amps and switched capacitors. The circuit is designed for circuit merit factor Q = 10. The proposed c...This paper proposes third order tunable bandwidth active Switched-Capacitor filter. The circuit consists of only op-amps and switched capacitors. The circuit is designed for circuit merit factor Q = 10. The proposed circuit implements three filter functions low pass, band pass and high pass simultaneously in single circuit. The filter circuit can be used for both narrow as well as for wide bandwidth. For various values of cut-off frequencies the behaviour of circuit is studied. The circuit works properly only for higher central frequencies, when f0 > 10 kHz.展开更多
机动飞行条件下高速转子系统会同时受到环境载荷以及转子自身的共同激励而产生强烈的强迫响应。为研究其复杂的振动特性,本文采用Vold-Kalman滤波(Vold-Kalman Filter,VKF)对不同基础运动激励下转子系统的实测振动信号进行阶次跟踪滤波...机动飞行条件下高速转子系统会同时受到环境载荷以及转子自身的共同激励而产生强烈的强迫响应。为研究其复杂的振动特性,本文采用Vold-Kalman滤波(Vold-Kalman Filter,VKF)对不同基础运动激励下转子系统的实测振动信号进行阶次跟踪滤波。为验证VKF的有效性及参数设置的可靠性,通过转子动力特性计算生成系统响应的仿真信号,并通过加噪处理模拟测量信号,然后通过VKF提取目标阶次的时域波形。通过陀螺运动转子动力学试验,测得不同基础转动激起的系统振动响应,组合使用VKF和计算阶次跟踪(Computed Order Tracking,COT)提取并分离了转子转频信号和基础低频信号的时域和阶次信息。结果表明,单轴滚转或俯仰运动均会激起与其频率一致的低频振动响应,且滚转、俯仰角速度的大小会影响该低频信号的幅值大小;随着基础运动角速度的变化,转子前四阶振动分量没有发生明显的变化,而基础运动频率与转频之间的频带区域有显著变化。此方法有效地提升了机动飞行下转子支承系统振动信号处理与分析的准确度和效率,降低了信号噪声。展开更多
This paper consolidates the activity of design and fabrication of 2.9 - 4.32 GHz, 4.3 - 6.42 GHz, and 6.4 - 8.4 GHz filter bank. Novel compact microstrip bandpass filters with stub-loaded multi-mode resonators are pro...This paper consolidates the activity of design and fabrication of 2.9 - 4.32 GHz, 4.3 - 6.42 GHz, and 6.4 - 8.4 GHz filter bank. Novel compact microstrip bandpass filters with stub-loaded multi-mode resonators are proposed. Simulated results indicate that all the filters exhibit insertion losses less than 1.5 dB with passband ripples of 1 dB and sharp attenuations of above 40 dB in their stopbands. The maximums of input and output VSWRs are 1.742 and 1.734, respectively. Due to fabrication error, the initial measured passbands show frequency shifts and insertion losses in upper passbands deteriorate seriously. After tuning of the filter bank, measured results imply that the input and output VSWRs are found lower than 2.135 and 2.187, and the insertion loss in 1 dB bandwidth is less than 2.52 dB. Filter bank has a sharp skirt and out-of-band rejection levels approaching to 40 dB in all desired stopbands except at the frequencies near 2f0.展开更多
A novel current mode active-only universal filter using four dual current output Operational Transconductance Amplifiers (OTAs) and three Operational Amplifiers (OAs) is presented. The circuit can realize low pass and...A novel current mode active-only universal filter using four dual current output Operational Transconductance Amplifiers (OTAs) and three Operational Amplifiers (OAs) is presented. The circuit can realize low pass and high pass filter characteristics by choosing the suitable current output branches. The filter performance factors natural frequency (ω0), bandwidth , quality factor Q and transconductance gain gm are electronically tunable. The proposed circuit has very low sensitivities with respect to circuit active elements. From sensitivity analysis, it has been clearly shown that the proposed circuit has very low sensitivities with respect to the circuit active elements. The gain roll-off of high pass and low pass configuration is 18 dB/oc- tave. The proposed circuit facilitates integrability, programmability and ease of implementation.展开更多
基金supported by the National Natural Science Foundation of China (60736043 60805012)the Fundamental Research Funds for the Central Universities (K50510020032)
文摘A novel particle filter bandwidth adaption for kernel particle filter （BAKPF） is proposed. Selection of the kernel bandwidth is a critical issue in kernel density estimation （KDE）. The plug-in method is adopted to get the global fixed bandwidth by optimizing the asymptotic mean integrated squared error （AMISE） firstly. Then, particle-driven bandwidth selection is invoked in the KDE. To get a more effective allocation of the particles, the KDE with adap- tive bandwidth in the BAKPF is used to approximate the posterior probability density function （PDF） by moving particles toward the posterior. A closed-form expression of the true distribution is given. The simulation results show that the proposed BAKPF performs better than the standard particle filter （PF）, unscented particle filter （UPF） and the kernel particle filter （KPF） both in efficiency and estimation precision.
文摘A novel elliptical patch resonator for a compact bandpass filter with tunable bandwidth is presented. This bandpass filter has the advantage of great flexibility in which the center frequency can be changed easily. The bandwidth of this filter can be modified by simply changing one variable, and this makes the proposed design unique. The order of the elliptical patch resonator can be increased, and three types of different orders of the same design are compared. The proposed filter can be used for future compact advanced wireless communication systems.
基金Supported by the National Natural Science Foundation of China(60972059)the General Project of Science and Technology of Xuzhou City(XM12B002)
文摘Aiming at the large cost of calculating variable bandwidth kernel particle filter and the high complexity of its algorithm,a self-adjusting kernel function particle filter is presented. Kernel density estimation is facilitated to iterate and obtain new particle set. And the standard deviation of particle is introduced in the kernel bandwidth. According to the characteristics of particle distribution,the bandwidth is dynamically adjusted,and the particle distribution can thus be more close to the posterior probability density model of the system. Meanwhile,the kernel density is used to estimate the weight of updating particle and the system state. The simulation results show the feasibility and effectiveness of the proposed algorithm.
文摘In software defined radio (SDR), sharp filters of different bandwidth are required to fine tune the desired channel. This requires different computational resources and large number of filter coefficients. This paper proposes a continuously variable bandwidth sharp finite impulse response (FIR) filter with low distortion and low complexity. For this, a fixed length FIR filter is used with two arbitrary sampling rate converters. This system can be used for both the continuous increase as well as decrease of the effective bandwidth of a filter. The low complexity and sharpness are achieved by using the frequency-response masking (FRM) approach for the design of the fixed length FIR filter. The sharp transition width leads to maximum rejection to channel interference in SDR.
文摘Most existing reconstruction algorithms for photoacoustic imaging (PAI) assume that transducers used to receive ultrasound signals have infinite bandwidth. When transducers with finite bandwidth are used, this assumption may result in reduction of the imaging contrast and distortions of reconstructed images. In this paper, we propose a novel method to compensate the finite bandwidth effect in PAI by using an optimal filter in the Fourier domain. Simulation results demonstrate that the use of this method can improve the contrast of the reconstructed images with finite-bandwidth ultrasound transducers.
文摘This paper proposes third order tunable bandwidth active Switched-Capacitor filter. The circuit consists of only op-amps and switched capacitors. The circuit is designed for circuit merit factor Q = 10. The proposed circuit implements three filter functions low pass, band pass and high pass simultaneously in single circuit. The filter circuit can be used for both narrow as well as for wide bandwidth. For various values of cut-off frequencies the behaviour of circuit is studied. The circuit works properly only for higher central frequencies, when f0 > 10 kHz.
文摘机动飞行条件下高速转子系统会同时受到环境载荷以及转子自身的共同激励而产生强烈的强迫响应。为研究其复杂的振动特性,本文采用Vold-Kalman滤波(Vold-Kalman Filter,VKF)对不同基础运动激励下转子系统的实测振动信号进行阶次跟踪滤波。为验证VKF的有效性及参数设置的可靠性,通过转子动力特性计算生成系统响应的仿真信号,并通过加噪处理模拟测量信号,然后通过VKF提取目标阶次的时域波形。通过陀螺运动转子动力学试验,测得不同基础转动激起的系统振动响应,组合使用VKF和计算阶次跟踪(Computed Order Tracking,COT)提取并分离了转子转频信号和基础低频信号的时域和阶次信息。结果表明,单轴滚转或俯仰运动均会激起与其频率一致的低频振动响应,且滚转、俯仰角速度的大小会影响该低频信号的幅值大小;随着基础运动角速度的变化,转子前四阶振动分量没有发生明显的变化,而基础运动频率与转频之间的频带区域有显著变化。此方法有效地提升了机动飞行下转子支承系统振动信号处理与分析的准确度和效率,降低了信号噪声。
文摘This paper consolidates the activity of design and fabrication of 2.9 - 4.32 GHz, 4.3 - 6.42 GHz, and 6.4 - 8.4 GHz filter bank. Novel compact microstrip bandpass filters with stub-loaded multi-mode resonators are proposed. Simulated results indicate that all the filters exhibit insertion losses less than 1.5 dB with passband ripples of 1 dB and sharp attenuations of above 40 dB in their stopbands. The maximums of input and output VSWRs are 1.742 and 1.734, respectively. Due to fabrication error, the initial measured passbands show frequency shifts and insertion losses in upper passbands deteriorate seriously. After tuning of the filter bank, measured results imply that the input and output VSWRs are found lower than 2.135 and 2.187, and the insertion loss in 1 dB bandwidth is less than 2.52 dB. Filter bank has a sharp skirt and out-of-band rejection levels approaching to 40 dB in all desired stopbands except at the frequencies near 2f0.
文摘A novel current mode active-only universal filter using four dual current output Operational Transconductance Amplifiers (OTAs) and three Operational Amplifiers (OAs) is presented. The circuit can realize low pass and high pass filter characteristics by choosing the suitable current output branches. The filter performance factors natural frequency (ω0), bandwidth , quality factor Q and transconductance gain gm are electronically tunable. The proposed circuit has very low sensitivities with respect to circuit active elements. From sensitivity analysis, it has been clearly shown that the proposed circuit has very low sensitivities with respect to the circuit active elements. The gain roll-off of high pass and low pass configuration is 18 dB/oc- tave. The proposed circuit facilitates integrability, programmability and ease of implementation.
