共查询到20条相似文献,搜索用时 854 毫秒
1.
2.
扇形微带短截线型滤波器的设计 总被引:1,自引:0,他引:1
采用扇形微带短截线作为滤波器的基本单元,设计出具有宽频特性的滤波器,在微波平面电路的设计中有着良好的应用前景。通过设计扇形微带短截线单元的物理尺寸,能够实现特定频段的高选择性滤波器。用ADS和HFSS对这种新型滤波器与传统直形滤波器进行了特性对比,在特性方面,新型滤波器比传统滤波器具有更陡峭的过渡带和更宽的频带等优点;在结构方面,新型滤波器电路相对传统滤波器可以减少基板面积。 相似文献
3.
4.
针对基于小波变换与Kalman滤波相结合的多尺度联合估计方法中存在的问题,本文利用新的系统分块技术与多尺度变换方法相结合,建立一个动态系统基于时域与频域相结合的多尺度联合滤波器.首先,将时域中描述的状态方程和观测方程改写为块状态方程和块观测方程;利用多尺度变换技术在时域和频域中联合描述它们;结合Kalman滤波与顺序滤波的思想,建立了一类应用于动态系统的多尺度估计联合滤波器.新滤波器不仅保留了传统Kalman滤波器的实时性和递归性等优良性质,而且在滤波过程中还具有对随机状态信号进行多尺度分析的能力.计算机仿真实验验证了利用新估计器得到的估计精度可与利用传统Kalman滤波器得到的估计精度相媲美. 相似文献
5.
A new class of parallel-coupled line filters with broad stopband response is introduced. The design is based on the synthesis of bandpass prototypes with pre-defined upper stopband characteristics. The new filters have uniform- and stepped-impedance resonators, some of which are loaded by open-circuited stubs at their open-circuited ends. A seventh-order filter implementation is presented with a fundamental passband centered at 1 GHz. The measured wide-band transmission characteristic of the filter demonstrated a broad upper stopband and was in agreement with simulations. The performance of the new filter is also compared with the characteristic of a conventionally designed filter to highlight the advantages of the proposed design method. 相似文献
6.
A new odd-symmetric filter for ISI suppression and VSB transmission is proposed. The frequency response of the proposed filter is similar to that of an ideal raised-cosine filter, but in contrast to raised-cosine the new filter is realizable, e.g. using simple active filters. Simulation results show that concerning ISI suppression the new filter is significantly more efficient than the classical Butterworth or Chebyshev filters. The proposed filter can be also used as a VSB filter for TV modulators and demodulators. 相似文献
7.
《Microwave Theory and Techniques》1985,33(6):510-518
A new high-performance surface-acoustic-wave (SAW) filter for use in mobile telephones is presented in this paper. The design for the actual realization of the new filter is examined, from the new filter configuration to the final device operation, A low-loss weighting technique in an interdigital transducer (IDT), a new resonant structure, computer simulation procedures, and material properties are treated. Experimental results with this SAW filter included an 830-MHz center frequency, 3-percent bandwidth, insertion loss of as low as 3.5 ~ 4.0 dB, and 50-dB sidelobe suppression filter. 相似文献
8.
Photonic notch filter without optical coherence limitations 总被引:1,自引:0,他引:1
A new topology for a photonic notch filter that can solve the coherent interference problem in photonic signal processors is presented in this paper. It is based on a double-pass modulation technique. The key advantage of this new structure is that it completely removes the dominant phase noise limitation, which is a fundamental problem with existing incoherent processor approaches. It also enables arbitrary narrow-linewidth telecommunication-type lasers to be used with stable and robust filter operation. Extensions to obtain tunable notch frequency and wide-passband notch filter operation are presented. Results demonstrate robust notch filter operation with a narrow-linewidth source, no phase-induced intensity noise, and a vastly superior signal-to-noise ratio performance (i.e., a nearly 60-dB increase) compared with the conventional delay line notch filter. Tunable coherence-free operation of the notch filter is also shown. Finally, a new structure that not only operates without coherence limitations but also realizes a notch filter with a wide passband of more than 50% of the free spectral range is demonstrated. 相似文献
9.
A novel pulse shaping filter satisfying the Nyquist-I criterion was derived and implemented to reduce the peak-to-average power ratio (PAPR) over a Single Carrier Frequency Division Multiple Access (SC-FDMA) scheme. The new filter reduces the PAPR, while maintaining the same excess bandwidth and the zero intersymbol interference condition. The novel filter contains a new design parameter β to minimize PAPR, which is independent from the roll-off factor α. The minimum PAPR of the SC-FDMA scheme is linked to the value given to the parameter β for a specific roll-off factor α. Several simulations showed that PAPR is reduced greatly compared to that of the raised cosine filter, which is widely used in wireless communications. The performance of the proposed pulse shaping filter, regarding PAPR, is also compared with those of other conventional filters, demonstrating that the new filter has a superior performance. 相似文献
10.
Dong-Won Kim Jeong-Hae Lee 《Microwave and Wireless Components Letters, IEEE》2005,15(5):351-353
A partial H-plane filter, which can be compared with a conventional E-plane filter, is proposed as a new type of compact direct-coupled resonator filter. The partial H-plane filter has the same frequency response as that of the E-plane filter while its cross section is one quarter. Measured results are in good agreement with computed results. 相似文献
11.
12.
针对目标检测概率较低导致单个传感器无法对目标进行有效检测并跟踪的问题,本文提出了多传感器箱粒子概率假设密度(multi-sensor box particle probability hypothesis density filter,MS-BOX-PHD)滤波器。MS-BOX-PHD滤波器首先将多个传感器的量测转换、融合成为一个量测集合,并利用箱粒子概率假设密度(box particle probability hypothesis density filter,BOX-PHD)滤波器对多个目标的状态进行预测和更新。数值实验表明,相较于单传感器箱粒子概率假设密度(Single-BOX-PHD)滤波器,MS-BOX-PHD滤波器在目标检测概率较低时,能够有效地对多目标的状态和数目进行估计;相较于区间量测下多传感器标准PHD粒子(multi-sensor standard probability hypothesis density particle filter with interval measurement,IM-PHD-PF)滤波器,在达到相同的跟踪性能时,计算效率提升了38.57%。 相似文献
13.
14.
Min Hwan Kwak Seok Kil Han Kwang-Yong Kang Dal Ahn Joom-Suk Suh Sang Hyun Kim 《Applied Superconductivity, IEEE Transactions on》2001,11(2):4023-4026
A new type of low-pass filter based on a coupled line and transmission line theory is proposed for suppressing harmonics and spurious frequency. The seventh-order coupled-line low-pass filter with strip line configuration was fabricated using a high-temperature superconducting (HTS) thin film on MgO(100) substrate. The seventh-order low-pass filter has five attenuation poles in the stop band. Its cutoff frequency is 1 GHz with a 0.01-dB ripple level. The fabricated filter exhibits a characteristic stop band in the range from 1 to 7 GHz. A measured insertion loss at the pass-band of the HTS low-pass filter is 0.2 dB at 77 K, while the maximum return loss is 17.1 dB. These results match well with those obtained by the EM simulation. The new low-pass filter structure is shown to have attractive properties such as compact size, wide stop band range, and low insertion loss 相似文献
15.
A new approach to subband adaptive filtering 总被引:2,自引:0,他引:2
Subband adaptive filtering has attracted much attention lately. In this paper, we propose a new structure and a new formulation for adapting the filter coefficients. This structure is based on polyphase decomposition of the filter to be adapted and is independent of the type of filter banks used in the subband decomposition. The new formulation yields improved convergence rate when the LMS algorithm is used for coefficient adaptation. As we increase the number of bands in the filter, the convergence rate increases and approaches the rate that can be obtained with a flat input spectrum. The computational complexity of the proposed scheme is nearly the same as that of the fullband approach. Simulation results are included to demonstrate the efficacy of the new approach 相似文献
16.
In this paper, a paradigm is developed to design the linear-phase FIR multiple-notch filters with variable notch frequencies. The design procedure can be proceeded through two steps: First, a linear-phase narrow-band low-pass filter met the given bandwidth and stopband ripple specifications is designed. Second, a tuning procedure is applied to the computed low-pass filter to yield the desired multiple-notch filter. When the notch frequencies are varied, the same tuning procedure can be employed to render the multiple-notch filter with the new set of the notch frequencies. The tuning procedure employed reduces the computational complexity of designing the multiple-notch filter with the new set of the notch frequencies. The simulation results demonstrate the effectiveness of our scheme. 相似文献
17.
In this paper, a new current-mode universal active-RC filter is proposed. The proposed circuit is based on a new universal
passive filter topology. This passive filter is generated from a classical well known current-mode universal passive filter
applying a transformation procedure. Two Fully Differential Current Conveyors (FDCCII) are used to construct a universal active-RC
filter from this passive filter. The FDCCII based proposed filter has only grounded resistors and capacitors as the passive
elements. The circuit simultaneously provides the three basic filter characteristics, namely high-pass (HP), band-pass (BP)
and low-pass (LP). SPICE simulation results are given to verify the theoretical analysis. 相似文献
18.
19.
Goldstein J.S. Reed I.S. Scharf L.L. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1998,44(7):2943-2959
The Wiener filter is analyzed for stationary complex Gaussian signals from an information theoretic point of view. A dual-port analysis of the Wiener filter leads to a decomposition based on orthogonal projections and results in a new multistage method for implementing the Wiener filter using a nested chain of scalar Wiener filters. This new representation of the Wiener filter provides the capability to perform an information-theoretic analysis of previous, basis-dependent, reduced-rank Wiener filters. This analysis demonstrates that the cross-spectral metric is optimal in the sense that it maximizes mutual information between the observed and desired processes. A new reduced-rank Wiener filter is developed based on this new structure which evolves a basis using successive projections of the desired signal onto orthogonal, lower dimensional subspaces. The performance is evaluated using a comparative computer analysis model and it is demonstrated that the low-complexity multistage reduced-rank Wiener filter is capable of outperforming the more complex eigendecomposition-based methods 相似文献