Journal articles: 'Filters’ design'

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Mewada, Hiren K., and Jitendra Chaudhari. "Low computation digital down converter using polyphase IIR filter." Circuit World 45, no. 3 (August 5, 2019): 169–78. http://dx.doi.org/10.1108/cw-02-2019-0015.

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Purpose The digital down converter (DDC) is a principal component in modern communication systems. The DDC process traditionally entails quadrature down conversion, bandwidth reducing filters and commensurate sample rate reduction. To avoid group delay, distortion linear phase FIR filters are used in the DDC. The filter performance specifications related to deep stopband attenuation, small in-band ripple and narrow transition bandwidth lead to filters with a large number of coefficients. To reduce the computational workload of the filtering process, filtering is often performed as a two-stage process, the first stage being a down sampling Hoegenauer (or cascade-integrated comb) filter and a reduced sample rate FIR filter. An alternative option is an M-Path polyphase partition of a band cantered FIR filter. Even though IIR filters offer reduced workload to implement a specific filtering task, the authors avoid using them because of their poor group delay characteristics. This paper aims to propose the design of M-path, approximately linear phase IIR filters as an alternative option to the M-path FIR filter. Design/methodology/approach Two filter designs are presented in the paper. The first approach uses linear phase IIR low pass structure to reduce the filter’s coefficient. Whereas the second approach uses multipath polyphase structure to design approximately linear phase IIR filter in DDC. Findings The authors have compared the performance and workload of the proposed polyphase structured IIR filters with state-of-the-art filter design used in DDC. The proposed design is seen to satisfy tight design specification with a significant reduction in arithmetic operations and required power consumption. Originality/value The proposed design is an alternate solution to the M-path polyphase FIR filter offering very less number of coefficients in the filter design. Proposed DDC using polyphase structured IIR filter satisfies the requirement of linear phase with the least number of computation cost in comparison with other DDC structure.

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Chen, Zhimin, and Lenan Wu. "Design of Special Impacting Filter for Multicarrier ABPSK System." Mathematical Problems in Engineering 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/921932.

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A rather intuitive technique known as pole-zero placement is introduced to illustrate the frequency response of the special impacting filters (SIFs) with a pair of conjugate zero-poles and deduce the equation of the pole radii. Based on that, the paper proposes an iterative scheme to derive the parameters of the cascade notch filter. The cost function is determined by the cascading notch filter’s influence on impacting filters, converting the cost function’s least square problem to a filter parameters’ standard quadratic programming problem. Finally, a cascading notch SIF (CNSIF) designed to demodulate the ABPSK signals is realized.

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Jurisic Bellotti, Maja, and Mladen Vucic. "Sparse FIR Filter Design Based on Signomial Programming." Elektronika ir Elektrotechnika 26, no. 1 (February 16, 2020): 40–45. http://dx.doi.org/10.5755/j01.eie.26.1.23560.

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The goal of sparse FIR filter design is to minimize the number of nonzero filter coefficients, while keeping its frequency response within specified boundaries. Such a design can be formally expressed via minimization of l0-norm of filter’s impulse response. Unfortunately, the corresponding minimization problem has combinatorial complexity. Therefore, many design methods are developed, which solve the problem approximately, or which solve the approximate problem exactly. In this paper, we propose an approach, which is based on the approximation of the l0-norm by an lp-norm with 0 < p < 1. We minimize the lp-norm using recently developed method for signomial programming (SGP). Our design starts with forming a SGP problem that describes filter specifications. The optimum solution of the problem is then found by using iterative procedure, which solves a geometric program in each iteration. The filters whose magnitude responses are constrained in minimax sense are considered. The design examples are provided illustrating that the proposed method, in most cases, results in filters with higher sparsity than those of the filters obtained by recently published methods.

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Hou, Hai-Gang, Shahid Hussain, Hai-Cheng Shao, Gui-Wu Liu, Ming-Song Wang, Guan-Jun Qiao, and Asma Shaheen. "Experimental Insights on Factors Influencing Sensitivity of Thin Film Narrow Band-Pass Filters." Journal of Nanoelectronics and Optoelectronics 14, no. 11 (November 1, 2019): 1548–54. http://dx.doi.org/10.1166/jno.2019.2663.

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First time study for development of relationship between design and fabrication of thin film narrow-pass filters simulated using the Essential Macleod optical coating design program and verified through experimental data. In thin film narrow band-pass filter's design, can design better filter by changing some parameters, but the theoretical designs are often difficult to achieve. The sensitivity of thin film narrow band-pass filters are mainly influenced by the refractive index of cavity layers, number of mirror layers, interference order and number of cavities. Based on analysis of all these aspects, laws of influence are obtained. A narrow band-pass filter with super wide rejection band was designed and fabricated to verify the simulation results, showing a good agreement between the experimental and theoretical observations.

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Tüzün, Reşat, and Nursel Akçam. "Design of Microstrip Low Pass Filters." Academic Perspective Procedia 1, no. 1 (November 9, 2018): 47–55. http://dx.doi.org/10.33793/acperpro.01.01.13.

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Microstrip filters have a significant role in Radio Frequency/Microwave applications. Microstrip filters are common on microwave circuits, satellite communications, radars, test equipments and so on. Because microstrip filters are compact, cheap and easy to produce, they are highly preferred for microwave applications. Microwave filter; microwave system is a two-ported element used to control the frequency response at a certain point by attenuating the frequencies in the stop band by transmitting in the frequency band. Typical frequency responses are low pass, high pass, band pass and band stop. Also approaches such as Butterworth, Chebyshev, and Elliptic are defining filter characteristics. In this paper, microstrip filters havign Chebyshev, Elliptic and Maximally Flat approaches were designed. For example Chebyshev filter of design filters having 6 GHz cut frequency and having 46,34 dB at 6,6 GHz. The insertion loss is -3,66 dB at 6 GHz. AWR Sonnet is used for the simulation and analysis of this filters.

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Tsuno, K., T. Kaneyama, T. Honda, Y. Ishida, E. Munro, and J. Rouse. "Omega Filter design for a 200kv TEM." Microscopy and Microanalysis 5, S2 (August 1999): 344–45. http://dx.doi.org/10.1017/s143192760001504x.

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A new omega filter has successfully been installed in 200kV TEMs(see FIG. 1). Energy filtering TEM (EFTEM) is extremely useful to enhance contrast of biological specimens, to observe defects in thick semiconductor tips, to obtain a good compositional map in grain boundaries, to give structure image in the thick specimen regions and to obtain quantitative data by removing plasmon loss signals. In-column filters such as omega filter has advantages over postcolumn filters from points of cancellation of aberrations, to obtain iso-chromatic images and a freedom of selecting variety of magnifications.Here, we discuss conditions of designing an omega filter. In usually, curved axis systems, which are common to energy analysis equipment, has large second order aberrations. Those aberrations are compensated in analyzers with single sector magnet with multi stage sextupole correctors. However, the adjustment of those correctors is difficult and residual aberrations destroy quality of the filtered image.

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Linville, A. Frank. "Single‐channel digital filter design for seismic applications." GEOPHYSICS 59, no. 10 (October 1994): 1584–92. http://dx.doi.org/10.1190/1.1443547.

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A general least‐squares, time‐domain filter design methodology has been developed that is easy to use for a variety of seismic filtering applications. The 1-D finite‐impulse response frequency filter can efficiently provide the noise attenuation and selectivity needed in modern data processing. Flexibility of design allows a choice of all basic types of single‐channel filters commonly used in processing. These include low‐pass, high‐pass, band‐pass, band‐reject, and notch filters. In addition, multiple bands may be passed or rejected using a single operator design without increasing the length of the filter. The ability to reject multiple noise bands with one filter is convenient and also reduces data processing costs. The filter can be viewed as a minimum‐phase Wiener‐Levinson predictive deconvolution filter designed to reject specified frequency bands. The filter is designed from an exact mathematical description of the specified stop bands that provide an explicit expression for the required autocorrelation lags in the normal equations. The filter’s desired frequency response (transition zone width and rejection level) is simply related to two input parameters—operator length and white noise level.

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Al-Yasir, Yasir, Naser Ojaroudi Parchin, Raed Abd-Alhameed, Ahmed Abdulkhaleq, and James Noras. "Recent Progress in the Design of 4G/5G Reconfigurable Filters." Electronics 8, no. 1 (January 20, 2019): 114. http://dx.doi.org/10.3390/electronics8010114.

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Currently, several microwave filter designs contend for use in wireless communications. Among various microstrip filter designs, the reconfigurable planar filter presents more advantages and better prospects for communication applications, being compact in size, light-weight and cost-effective. Tuneable microwave filters can reduce the number of switches between electronic components. This paper presents a review of recent reconfigurable microwave filter designs, specifically on current advances in tuneable filters that involve high-quality factor resonator filters to control frequency, bandwidth and selectivity. The most important materials required for this field are also highlighted and surveyed. In addition, the main references for several types of tuneable microstrip filters are reported, especially related to new design technologies. Topics surveyed include microwave and millimetre wave designs for 4G and 5G applications, which use varactors and MEMSs technologies.

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Nguyen, Phuoc Si. "Infinite Impulse Response Digital Filters Design." International Journal of Signal Processing Systems 5, no. 2 (June 2017): 83–88. http://dx.doi.org/10.18178/ijsps.5.2.83-88.

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Rohini, R., N. V. Satya Narayana, and Durgesh Nandan. "A Crystal View on the Design of FIR Filter." Journal of Computational and Theoretical Nanoscience 17, no. 9 (July 1, 2020): 4235–38. http://dx.doi.org/10.1166/jctn.2020.9052.

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In audio and video signal processing main element is the FIR filter. This paper presents complete information regarding the FIR filters. It also focuses on the design of FIR filters which provide low-area, energy-delay, low-power consumption, high-speed, low critical path, and low complexity. Implementation of FIR filters with different methods like memory-based VLSI architecture, filters for sampling rate conversion, linear phase FIR filters, optimal hybrid form FIR filters, Nyquist filters, hybrid multiplier less FIR filters, low complexity FIR filters, variable partition hybrid form FIR filters, area efficiency FIR filters are discussed in this paper. The objective of this paper to provide all related information regarding FIR filters at one platform.

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KAELIN, AUGUST, and GEORGE S. MOSCHYTZ. "A NEW COMPREHENSIVE PROCEDURE FOR THE EXACT DESIGN OF CANONIC LDI-TYPE SC LADDER FILTERS." Journal of Circuits, Systems and Computers 01, no. 04 (December 1991): 417–41. http://dx.doi.org/10.1142/s021812669100015x.

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A new procedure is given for the exact design of canonic LDI-type SC ladder filters realizing any elliptic discrete-time transfer function, including highpass functions. We show that, in contrast to known exact design procedures, the underlying prototype network should be terminated with so-called half-unit delays in order to preserve the capability of realizing any filter type. We will show, based on such ladder prototypes, simple and stray-insensitive LDI-type SC ladder filters can be derived, which are canonical for any filter type (i.e., every filter pole requires for its realization one stray-insensitive SC integrator without the need for additional amplifiers). Compared to common exact design procedures, simpler SC ladder structures are obtained, in particular, for highpass-type filters. Exact designs of canonic SC highpass ladder filters are presented and compared with corresponding biquad designs.

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Qiu, Xinyi, Hui Feng, and Bo Hu. "Fractional Order Graph Filters: Design and Implementation." Electronics 10, no. 4 (February 10, 2021): 437. http://dx.doi.org/10.3390/electronics10040437.

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Existing graph filters, polynomial or rational, are mainly of integer order forms. However, there are some frequency responses which are not easily achieved by integer order approximation. It will substantially increase the flexibility of the filters if we relax the integer order to fractional ones. Motivated by fractional order models, we introduce the fractional order graph filters (FOGF), and propose to design the filter coefficients by genetic algorithm. In order to implement distributed computation on a graph, an FOGF can be approximated by the continued fraction expansion and transformed to an infinite impulse response graph filter.

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RECIOUI, Abdelmadjid, Fatma Zohra HAMRIOUI, Kenza BENAMROUCHE, and Oussama MERABET. "Analog Filter Design: A Succinct Investigation." Algerian Journal of Signals and Systems 3, no. 4 (December 15, 2018): 174–89. http://dx.doi.org/10.51485/ajss.v3i4.74.

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In many systems, it is essential to extract or enhance the desired information and remove the unwanted components. This is the simplest aim of signal processing where the filter turns out to be the key element. The objective of this paper is to investigate the characteristics of analog passive and active filters. Particularly, the interest goes to the conventional Butterworth, Chebychev and Bessel filter. A comparative study of these filters is done. The different circuits are simulated using the MULTISIM software to visualize the magnitude and phase responses. The procedure of designing the different filters is presented so that it can be used in any application.

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Jiang, Lei, Haijian Zhang, Shuai Cheng, Hengwei Lv, and Pandong Li. "An Overview of FIR Filter Design in Future Multicarrier Communication Systems." Electronics 9, no. 4 (March 31, 2020): 599. http://dx.doi.org/10.3390/electronics9040599.

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Future wireless communication systems are facing with many challenges due to their complexity and diversification. Orthogonal frequency division multiplexing (OFDM) in 4G cannot meet the requirements in future scenarios, thus alternative multicarrier modulation (MCM) candidates for future physical layer have been extensively studied in the academic field, for example, filter bank multicarrier (FBMC), generalized frequency division multiplexing (GFDM), universal filtered multicarrier (UFMC), filtered OFDM (F-OFDM), and so forth, wherein the prototype filter design is an essential component based on which the synthesis and analysis filters are derived. This paper presents a comprehensive survey on the recent advances of finite impulse response (FIR) filter design methods in MCM based communication systems. Firstly, the fundamental aspects are examined, including the introduction of existing waveform candidates and the principle of FIR filter design. Then the methods of FIR filter design are summarized in details and we focus on the following three categories—frequency sampling methods, windowing based methods and optimization based methods. Finally, the performances of various FIR design methods are evaluated and quantified by power spectral density (PSD) and bit error rate (BER), and different MCM schemes as well as their potential prototype filters are discussed.

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Vijayan, Smrithi, Nallaperumal Chellammal, and Tatipamula Mohana. "Design of Filters for Power Quality Improvement in Microgrids." Applied Mechanics and Materials 573 (June 2014): 673–78. http://dx.doi.org/10.4028/www.scientific.net/amm.573.673.

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This paper deals with the design of filters for power quality enhancement in microgrid. The voltage source inverters (VSI) fed from microgrid requires filter across them to detect the unbalance and harmonics in the system. The performances of various filters are compared and the improved negative sequence filter is found out to be the best solution. The stability of these filters are also studied and simulations are carried out to validate the results.

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Mitić, Darko, Goran Jovanović, Mile Stojčev, and Dragan Antić. "ON DESIGN OF SELF-TUNING ACTIVE FILTERS." Facta Universitatis, Series: Automatic Control and Robotics 19, no. 1 (July 28, 2020): 059. http://dx.doi.org/10.22190/fuacr2001059m.

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In this paper, we present one approach in design of self-tuning all-pass, band-pass, low-pass and notch filters based on phase control loops with voltage-controlled active components and analyze their stability as well. The main idea is to vary signal delay of the filter and in this way to achieve phase correction. The filter phase characteristics are tuned by varying the transconductance of the operational transconductance amplifier or capacitance of an MOS varicap element, which are the constituents of filters. This approach allows us to implement active filters with capacitance values of order of pF, making the complete filter circuit to be amenable for realization in CMOS technology. The phase control loops are characterized by good controllable delay over the full range of phase and frequency regulation, high stability, and short settling (locking) time. The proposed circuits are suitable for implementation as a basic building RF function block, used in phase and frequency regulation, frequency synthesis, clock generation recovery, filtering, selective amplifying etc.

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Chand, B., T. Kut, and S. Dickmann. "Optimal design of active EMC filters." Advances in Radio Science 11 (July 4, 2013): 243–49. http://dx.doi.org/10.5194/ars-11-243-2013.

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Abstract. A recent trend in automotive industry is adding electrical drive systems to conventional drives. The electrification allows an expansion of energy sources and provides great opportunities for environmental friendly mobility. The electrical powertrain and its components can also cause disturbances which couple into nearby electronic control units and communication cables. Therefore the communication can be degraded or even permanently disrupted. To minimize these interferences, different approaches are possible. One possibility is to use EMC filters. However, the diversity of filters is very large and the determination of an appropriate filter for each application is time-consuming. Therefore, the filter design is determined by using a simulation tool including an effective optimization algorithm. This method leads to improvements in terms of weight, volume and cost.

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Matei, Radu. "Design of Adjustable Square-Shaped 2D IIR Filters." ISRN Signal Processing 2013 (September 11, 2013): 1–10. http://dx.doi.org/10.1155/2013/796830.

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This paper proposes an analytical design method for two-dimensional square-shaped IIR filters. The designed 2D filters are adjustable since their bandwidth and orientation are specified by parameters appearing explicitly in the filter matrices. The design relies on a zero-phase low-pass 1D prototype filter. To this filter a frequency transformation is next applied, which yields a 2D filter with the desired square shape in the frequency plane. The proposed method combines the analytical approach with numerical approximations. Since the prototype transfer function is factorized into partial functions, the 2D filter also will be described by a factorized transfer function, which is an advantage in implementation.

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Hussain, Ghasan Ali. "DESIGN OF PARALLEL COUPLED MICROSTRIP BAND-PASS FILTER." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 15, no. 5 (April 21, 2016): 6768–75. http://dx.doi.org/10.24297/ijct.v15i5.1650.

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Filters occupy important acts in several Radio Frequency microwave applications. Several applications such as wireless communications still challenge RF/microwave filters with strict requirements such as smaller size, higher performance, lighter weight, and lower cost. Microstrip Filters for RF/Microwave Applications offers a unique and comprehensive treatment of RF/microwave filters based on the microstrip structure. One of the most common methods in designing microwave filters is using of parallel-coupled microstrip. In this paperÂ simulate and fabricate by using Ansoft Designer a two resonator microstrip band-pass filter suitable for Wi-Fi applications.Â The results of simulation were quite good.

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Lim, Sungyung, Homer D. Stevens, and Jonathan P. How. "Input Shaping Design for Multi-Input Flexible Systems." Journal of Dynamic Systems, Measurement, and Control 121, no. 3 (September 1, 1999): 443–47. http://dx.doi.org/10.1115/1.2802494.

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This paper investigates a new design technique of input shaping filters for multi-input flexible systems using convex optimization synthesis techniques for finite impulse response filters (FIR filters). The objective of the input shaping filter design is to find the minimum length and the minimum number of nonzero impulses of the FIR filter that forces the system to track the reference command without any residual vibration, while satisfying additional performance and control constraints. This multi-objective optimization is solved using a two-step algorithm that sequentially solves two quasi-convex optimization problems. Compared with previously published nonlinear optimization approaches, this new approach does not require a priori knowledge of the forms of input shaping filters and enables much greater flexibility for including additional performance and robustness objectives. Furthermore, this convex-based approach can be applied to multi-input systems. The multiple input shaping filter has been experimentally verified on the Stanford University Two-Link Flexible Manipulator.

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Fernandez-Vazquez, Alfonso, and Gordana Jovanovic Dolecek. "Generalized Chebyshev Filters for the Design of IIR Filters and Filter Banks." Circuits, Systems, and Signal Processing 33, no. 7 (February 20, 2014): 2237–50. http://dx.doi.org/10.1007/s00034-014-9742-4.

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Yue, Dachao, and Haikuan Liu. "The Design Of Intelligent Filter For EEG." MATEC Web of Conferences 232 (2018): 04023. http://dx.doi.org/10.1051/matecconf/201823204023.

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EEG data processing method is usually digital filter designed by the traditional method. Its disadvantage is the transition zone is wide and the filtering effect is poor. Using an improved particle swarm optimization algorithm on IIR digital filters design, the performances of filters designed by various methods are compared and analyzed. Experiments illustrate particle swarm optimization algorithm is effective in IIR filter design and its performance is promising.

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Nalli, Praveen Kumar, Kalyan Sagar Kadali, Ramu Bhukya, Y. T. R. Palleswari, Asapu Siva, and S. Pragaspathy. "Design of Exponentially Weighted Median Filter Cascaded With Adaptive Median Filter." Journal of Physics: Conference Series 2089, no. 1 (November 1, 2021): 012020. http://dx.doi.org/10.1088/1742-6596/2089/1/012020.

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Abstract The objective of this paper is to design an II phase algorithm employing median filters for enlightening the performance in removing impulse noise during the processing of the image. The cascaded filter section employs an Adaptive median filter in the first phase followed by a Recursive weighted median filter (RWM) in the second phase. The RWM filter weight is selected with the Median Controlled Algorithm. As a design parameter, the exponential weights of RWM filters are used in the feedback path. The projected algorithm can achieve suggestively improved quality of image when compared to fixed weight or the Center Weighted Median filters.

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Chen, Jing, Chang Yin Liu, and Xue Ping Li. "The Design and FPGA Implementation of a Polyphase SRRC FIR Filter in DTMB." Advanced Materials Research 791-793 (September 2013): 2122–26. http://dx.doi.org/10.4028/www.scientific.net/amr.791-793.2122.

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Polyphase FIR filters are applied in many practical Digital Signal Processing applications where the sampling rate needs to be changed. This paper focuses on the implementation of polyphase square root raised cosine (SRRC) FIR filter based on Field Programmable Gate Array (FPGA). The filter employs methods like filter's multiphase structure, symmetrical coefficients, I/Q channel multiplexing, pipeline addition and so on to design the SRRC filter. Compared with the traditional method, the designed FIR filter exhibits the advantages of high response speed and low hardware resource s consumption.

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Capobianco, Giovanni, Carmine Cerrone, Andrea Di Placido, Daniel Durand, Luigi Pavone, Davide Donato Russo, and Fabio Sebastiano. "Image convolution: a linear programming approach for filters design." Soft Computing 25, no. 14 (April 26, 2021): 8941–56. http://dx.doi.org/10.1007/s00500-021-05783-5.

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AbstractImage analysis is a branch of signal analysis that focuses on the extraction of meaningful information from images through digital image processing techniques. Convolution is a technique used to enhance specific characteristics of an image, while deconvolution is its inverse process. In this work, we focus on the deconvolution process, defining a new approach to retrieve filters applied in the convolution phase. Given an image I and a filtered image $$I' = f(I)$$ I ′ = f ( I ) , we propose three mathematical formulations that, starting from I and $$I'$$ I ′ , are able to identify the filter $$f'$$ f ′ that minimizes the mean absolute error between $$I'$$ I ′ and $$f'(I)$$ f ′ ( I ) . Several tests were performed to investigate the applicability of our approaches in different scenarios. The results highlight that the proposed algorithms are able to identify the filter used in the convolution phase in several cases. Alternatively, the developed approaches can be used to verify whether a specific input image I can be transformed into a sample image $$I'$$ I ′ through a convolution filter while returning the desired filter as output.

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DEKHANDJI, Fatma Zohra. "Design Optimization of PMU Anti-Aliasing Filters using Taguchi Method." Algerian Journal of Signals and Systems 5, no. 4 (December 15, 2020): 215–19. http://dx.doi.org/10.51485/ajss.v5i4.119.

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A Phasor Measurement Unit (PMU) is a monitoring device, which serves in checking the power system condition by measuring voltage and current phasors along with frequency at a particular node. The basic structure of PMU consists of Synchronization Unit, Measurement Unit and Data Transmission Unit. The Measurement Unit has three components: Anti-aliasing filters, Analog-to-Digital Converter and Phasor measurement Unit/ Processor. An anti-aliasing filter ensures that all the analog signals have the same phase shift and attenuation thus assuring that the phase angle differences and relative magnitudes of the different signals are unchanged. Anti-aliasing filters made up of an analog front end and a digital decimation filter are far more stable as far as aging and temperature variations are concerned. IEEE C37.118 standard stipulates that it is mandatory to use the filter for avoiding any aliasing errors. Out of various analog filters, the Butterworth has been preferred due to its flat response in pass-band as compared to other filters. In this work, it is attempted to design anti-aliasing filters to be used in PMUs. The design problem is formulated as an optimization task that is solved using the Taguchi method. The results show better performance in terms characteristics compared to the conventional filters. The designed filters may be employed as building blocks in modern PMUs.

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Konopacki, Jacek, and Katarzyna Mościńska. "A Procedure for Quasi-Equiripple Linear-Phase IIR Filters Design." International Journal of Electronics and Telecommunications 56, no. 4 (November 1, 2010): 393–98. http://dx.doi.org/10.2478/v10177-010-0052-x.

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A Procedure for Quasi-Equiripple Linear-Phase IIR Filters DesignThe linear-phase IIR filters are described in many cases, mainly due to distortion-free transmission of signals. One of the major problems of IIR filter design is stability, which can be obtained with suitable value of group delay τ. This paper concerns calculation of filter orderNand group delay τ in case of quasi-equiripple design of IIR filters. We propose a novel procedure for determiningNand τ values; the procedure is valid for all types of filters with arbitrary number of zeros and a few non-zero poles. Evaluation of the proposed approach as well as examples illustrating its application are provided in the paper.

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Chervinskiy, Evgeniy N. "DESIGN OF BAND-PASS FILTERS WITH NON-EQUIRIPPLE FREQUENCY RESPONSES." Journal of the Russian Universities. Radioelectronics 22, no. 3 (July 2, 2019): 5–23. http://dx.doi.org/10.32603/1993-8985-2019-22-3-5-23.

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Introduction. Band-pass filters circuit elements can be calculated by converting low-pass filter (LPF) parameters, which is the prototype of the designed band-pass filter. The conversion causes problems in case calculated values of circuit elements (resistors and capacitors) are out of standard values determined by the GOST standard. Obviously, frequency characteristics of band-pass filters are distorted when replacing the calculated values of circuit elements by the standard ones. The number of circuit elements with values different from standard can be reduced to zero by solving an additional system of equations that connects parameters of designed and reintroduced non-equiripple frequency responses. Objective. The objective of this work is to develop a calculation method of band-pass ladder filters with values of circuit elements corresponding to standard ones. Materials and methods. The filter design process includes two stages. The first stage is a parameters calculation of a polynomial LPF prototype. The calculated parameters are determined as a system of equations solution set. The equations are formed by equating coefficients of variables raised to the same powers in transfer function (TF) expressions of designed and realized filters. Initial characteristics are the filter order and frequency response unevenness. The transition to the standard values of circuit elements can be done when solving another system of equations that connects LPF converted parameters with unknown parameters of reintroduced non-equiripple frequency response. Results. TF of LPF prototypes up to the fifth order and frequency responses of band-pass filters (BPF) and bandrejection filters up to the tenth order are presented. Analytical expressions of non-equiripple and equiripple frequency responses are used to estimate distortions of the latter when a band-pass filter center frequency is tuned by using variable inductors or capacitors. The integral quadratic function of a variable is taken as a measure of real frequency response distortions. The tenth order BPF calculation example is given. Conclusion. The presented calculation methods of band-pass filters and given example demonstrate possibilities of the filter design method based on the systems of non-linear equations solution. In contrast to approximation methods of ideal filter frequency response by using special functions and tabular filters design, the presented method allows high-order filter calculation for any initial requirements without using reference data.

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YUCE, ERKAN, and SEZAI TOKAT. "DESIGN AND STABILITY ANALYSIS OF MIXED-MODE FILTERS CONTAINING ONLY GROUNDED CAPACITORS." Journal of Circuits, Systems and Computers 19, no. 06 (October 2010): 1345–63. http://dx.doi.org/10.1142/s0218126610006864.

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In this paper, three dual-mode (mixed-mode) analog filters using only grounded capacitors and two to three second-generation current conveyors (CCIIs) are presented. The first proposed filter can provide a transimpedance-mode (TIM) second-order filter transfer function (TF), and is free from passive component matching constraints, which is advantageous in integrated circuit (IC) design. Other two mixed-mode filters having the property of tunability are derived from the first proposed filter. However, the developed filters in this work, like other active filters, suffer from nonidealities such as nonideal gain and parasitic impedance effects which increase the order of the filter TFs; accordingly, stability problem may arise. In this study, stability analysis using gain and phase margins is accomplished. To explain the claimed ideas, several computer simulations and an experimental test are performed.

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Baranowski, Jerzy, and Paweł Piątek. "Fractional Band-Pass Filters: Design, Implementation and Application to EEG Signal Processing." Journal of Circuits, Systems and Computers 26, no. 11 (March 21, 2017): 1750170. http://dx.doi.org/10.1142/s0218126617501705.

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Fractional band-pass filters are a promising area in the signal processing. They are especially attractive as a method for processing of biomedical signals, such as EEG, where large signal distortion is undesired. We present two structures of fractional band-pass filters: one as an analog of classical second-order filter, and one arising from parallel connection of two fractional low-pass filters. We discuss a method for filter implementation — Laguerre Impulse Response Approximation (LIRA) — along with sufficient conditions for when the filter can be realized with it. We then discuss methods of filter tuning, in particular we present some analytical results along with optimization algorithm for numerical tuning. Filters are implemented and tested with EEG signals. We discuss the results highlighting the possible limitations and potential for development.

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Hruschka, Crassen, Udo Barabas, and Lutz Gohler. "Optical narrow band filter without resonance's." Facta universitatis - series: Electronics and Energetics 17, no. 2 (2004): 209–17. http://dx.doi.org/10.2298/fuee0402209h.

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This paper introduces an optical wave filter, which uses gratings at 45? or 135? inclined grating lines that avoid any resonance's. Therefore, many more options to form the filter shape exist. In general, the filter design can be traced to that of transversal filters (finite impulse response filter, FIR filter). Such an integrated optical wave filter is characterized by steep filter slopes and a narrow pass band (less then 01nm) combined with a high stop band attenuation (more than 40dB) and a linear phase response in the pass band. Compared to conventional Bragg grating filters, the inclined grating line filters can have a flatter pass band and steeper filter skirts related to the width of the pass band. In general, the filter's realization is possible using any optical material. In view of the excellent optical properties the semiconductor material system InP/InGaAsP is used for manufacturing the filter.

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Blok, Marek. "FIR Filter Design Using Distributed Maximal Flatness Method." International Journal of Electronics and Telecommunications 59, no. 1 (March 1, 2013): 59–66. http://dx.doi.org/10.2478/eletel-2013-0007.

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Abstract In the paper a novel method for filter design based on the distributed maximal flatness method is presented. The proposed approach is based on the method used to design the most common FIR fractional delay filter - the maximally flat filter. The MF filter demonstrates excellent performance but only in a relatively narrow frequency range around zero frequency but its magnitude response is no greater than one. This ,,passiveness” is the reason why despite of its narrow band of accurate approximation, the maximally flat filter is widely used in applications in which the adjustable delay is required in feedback loop. In the proposed method the maximal flatness conditions forced in standard approach at zero frequency are spread over the desired band of interest. In the result FIR filters are designed with width of the approximation band adjusted according to needs of the designer. Moreover a weighting function can be applied to the error function allowing for designs differing in error characteristics. Apart from the design of fractional delay filters the method is presented on the example of differentiator, raised cosine and square root raised cosine FIR filters. Additionally, the proposed method can be readily adapted for variable fractional delay filter design regardless of the filter type.

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RAMÍREZ, JAVIER, UWE MEYER-BÄSE, and ANTONIO GARCÍA. "EFFICIENT RNS-BASED DESIGN OF PROGRAMMABLE FIR FILTERS TARGETING FPL TECHNOLOGY." Journal of Circuits, Systems and Computers 14, no. 01 (February 2005): 165–77. http://dx.doi.org/10.1142/s0218126605002131.

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FIR filters are routinely used in the implementation of modern digital signal processing systems. Their efficient implementation using commercially available VLSI technology is a subject of continuous study and development. This paper presents the residue number system (RNS) implementation of reduced-complexity and high-performance FIR filters, using modern Altera APEX20K field-programmable logic (FPL) devices. Index arithmetic over Galois fields and the Quadratic Residue Number System (QRNS), along with a selection of a small wordwidth modulus set, are the keys for attaining low complexity and high throughput in real and complex FIR filters. RNS–FPL merged FIR filters demonstrated its superiority when compared to 2C (two's complement) filters, being about 65% faster and requiring fewer logic elements for most study cases. Special attention was paid to an efficient implementation of the multi-operand modulo adders. The replacement of a classical modulo adder tree by a binary adder with extended precision followed by a single modulo reduction stage reduced area requirements by 10% for a 32-tap FIR filter. On the other hand, an index arithmetic QRNS-based complex FIR filter yielded up to 60% performance improvement over a three-multiplier-per-tap 2C filter, while requiring fewer LEs for filters having more than eight taps. Particularly, a 32-tap filter needed 24% LEs less than the classical design.

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Liu, Jiani, Elvin Isufi, and Geert Leus. "Filter Design for Autoregressive Moving Average Graph Filters." IEEE Transactions on Signal and Information Processing over Networks 5, no. 1 (March 2019): 47–60. http://dx.doi.org/10.1109/tsipn.2018.2854627.

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Jun, Wang, and Anand Asundi. "Strain contouring with Gabor filters: filter bank design." Applied Optics 41, no. 34 (December 1, 2002): 7229. http://dx.doi.org/10.1364/ao.41.007229.

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Jovanovic-Dolecek, G., and J. Javier Diaz Carmona. "Lowpass minimum phase filter design using IFIR filters." Electronics Letters 33, no. 23 (1997): 1933. http://dx.doi.org/10.1049/el:19971330.

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RAMACHANDRAN, V., and V. NINOV. "2D ZERO-PHASE FIR FILTER DESIGN WITH NONUNIFORM FREQUENCY SAMPLING." Journal of Circuits, Systems and Computers 10, no. 05n06 (October 2000): 239–77. http://dx.doi.org/10.1142/s0218126600000172.

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In this paper, nonuniform frequency sampling techniques used in the design of two-dimensional zero-phase FIR filters are proposed and investigated. The design problem is treated as a bivariate interpolation problem with unevenly spaced data. The main idea is to select (find) sampling locations in the (ω1, ω2) frequency plane and corresponding sample values Hd(ω1k, ω2k) of the desired filter frequency response such that the designed filter performance is high. Although the filters designed with the proposed techniques are not optimal, the methods are conceptually simple and produce filters with high degree of shape regularity and approximation error comparable and sometimes even smaller than the "conventional" 2D FIR filter design methods.

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Abousaif, Ehab, Aicha Elshabini, and Fred Barlow. "Waveguide Inductive Strip Filter Embedded in LTCC." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, CICMT (September 1, 2011): 000043–49. http://dx.doi.org/10.4071/cicmt-2011-ta21.

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Microwave filters are generally designed with microwave transmission lines. However these filters are typically lossy. The waveguide filters using conventional inductive elements such as metal rods and transverse diaphragm have some disadvantages such as complicated structure, high cost and they can be hard to mass produce. But they also have many advantages such as the capability of high power transmission, a non-radiating structure, and their thermal efficiency. A novel waveguide inductive strip filter embedded in LTCC is introduced in this paper where the disadvantages of the conventional waveguide filters are eliminated. By using LTCC technology, the cost will typically be lower, it can easily be mass produce, and these designs can also be tested easily. The equivalent T-network parameters of the inductive strip mounted in a waveguide and embedded in LTCC substrate were derived. A new iterative technique was used based on the Variation principle. The design formulas and curves of the filter were presented. The design method of the filter was derived by applying the equivalent network of the inductive strip to the usual method of the filter design. A complete set of new curves relating the various filter parameters were introduced. Similar curves can be derived to design similar filters for any frequency band using any dielectric material. Three-dimensional electromagnetic field modeling and simulation was carried out using HFSS (High Frequency Structure Simulator). An optimization process was done for the designed filter. The modeling and the optimization S-parameters curves are shown. This paper introduces a new methodology of designing waveguide inductive strip filters embedded in LTCC. The design methodology was derived and presented with formulas and curves. The design steps are explained and verified by examples and results.

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Hsu, Fu Yuan, Cheng Lung Li, and John Campbell. "Ceramic Foam Filters in Runner System Design for Castings." Key Engineering Materials 573 (September 2013): 19–29. http://dx.doi.org/10.4028/www.scientific.net/kem.573.19.

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In the design of runner systems, ceramic foam filters are used for reducing the velocity of liquid metal in order to avoid so called bifilm defect resulting from a high gating velocity (over its critical gating velocity) in aluminum gravity casting. In this study, two types of runner systems incorporated with the ceramic foam filters were designed. In order to observe the flow phenomena in these two runner systems with and without the filters, a water analogy experiment in a transparent plastic mold was utilized. Furthermore, in order to understand the effect of the filters used in these systems, an aluminum sand casting experiment was conducted. The quality of the cast metal in the outlet area of the filter for these systems was investigated. The defect content of this casting sample was measured by the re-melt reduced pressure test (re-melt RPT) and followed by measuring its bulk density. An optimized runner system with the filter was suggested in this study. Keywords: ceramic foam filter, runner system design, gravity casting, critical gating velocity, bifilm defect.

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Juan, Zhang, Guo Sen, and Li Xue. "Design of Optical Notch Filters Based on Equivalent Relations." Advanced Materials Research 679 (April 2013): 47–52. http://dx.doi.org/10.4028/www.scientific.net/amr.679.47.

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The transfer functions of optical notch filters based on all fiber unbalanced Mach-Zehnder interferometer with fiber ring coupled structure and Michelson Gires–Tournois interferometer structure are presented based on z-transform method respectively. On this basis, the structural parameters between the two kinds of notch filters are revealed to have some certain equivalent relations. With this equivalent relationship, the structural parameters for designing one of the two kinds of notch filter can be conveniently obtained by that of the other of the two kinds of notch filters. A design example of a two notch point notch filter using the method is given in detail in the paper.

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Miljanović, Dejan, Milka Potrebić, and Dejan V. Tošić. "Design of Microwave Multibandpass Filters with Quasilumped Resonators." Mathematical Problems in Engineering 2015 (2015): 1–14. http://dx.doi.org/10.1155/2015/647302.

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Design of RF and microwave filters has always been the challenging engineering field. Modern filter design techniques involve the use of the three-dimensional electromagnetic (3D EM) solvers for predicting filter behavior, yielding the most accurate filter characteristics. However, the 3D EM simulations are time consuming. In this paper, we propose electric-circuit models, instead of 3D EM models, suitable for design of RF and microwave filters with quasilumped coupled resonators. Using the diakoptic approach, the 3D filter structure is decomposed into domains that are modeled by electric networks. The coupling between these domains is modeled by capacitors and coupled inductors. Furthermore, we relate the circuit-element values to the physical dimensions of the 3D filter structure. We propose the filter design procedure that is based on the circuit models and fast circuit-level simulations, yielding the element values from which the physical dimensions can be obtained. The obtained dimensions should be slightly refined for achieving the desired filter characteristics. The mathematical problems encountered in the procedure are solved by numerical and symbolic computations. The procedure is exemplified by designing a triple-bandpass filter and validated by measurements on the fabricated filter. The simulation and experimental results are in good agreement.

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Zhao, Hui, Shengnan Li, Hongyu Yang, and Quan Zhou. "A stability controlling-based approach for designing 1-D variable fractional delay all-pass filters." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, no. 6 (November 5, 2018): 2224–31. http://dx.doi.org/10.1108/compel-01-2018-0053.

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Purpose Variable fractional delay filtering is an important technology in signal processing; the research shows that all-pass variable fractional delay (VFD) filters achieve higher design accuracy than FIR VFD filters; therefore, the design, analysis and implementation of all-pass VFD filters are of great importance. Design/methodology/approach In this paper, a two-stage approach for the design of general 1-D stable VFD all-pass filters is proposed. The method takes the desired group delay range [N−1, N], where N is the filter order. Findings The design algorithm is decomposed into two design stages: first, a set of fixed delay all-pass filters are designed by minimizing a set of objective functions defined in terms of approximating error criterion and filter stability constraint. Then, the design result is determined by fitting each of the fixed delay all-pass filter coefficients as 1-D polynomials. A design example together with its comparisons with those of the recent literature studies is given to justify the effectiveness of the proposed design method. Originality/value An illustrating design example shows that the method proposed can achieve better filter performances than the existing ones.

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Tiede, Jonas F., and Thomas F. Eibert. "Design and Realization of Chebyshev Bandstop Filters Based on Ceramic Resonators." Advances in Radio Science 19 (December 17, 2021): 117–26. http://dx.doi.org/10.5194/ars-19-117-2021.

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Abstract. Distributed bandpass or band-reject filters generally become larger as the design center frequency decreases. To achieve suitable filters with small dimensions even at center frequencies below 2 GHz, ceramic resonators can be used. These components essentially represent transmission lines with a specified, potentially large permittivity, making them physically short while maintaining a desired electrical length. In this paper, Chebyshev-approximated band-reject filters using capacitors and transmission lines, the latter being represented by ceramic resonators, are investigated. Three filter prototypes are built and their performance is evaluated by measurements. Reasonable bandstop filter properties are found, which are the better the narrower the filter bandwidth is.

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Chung, Daewon, Woon Cho, Inyeob Jeong, and Joonhyeon Jeon. "Design of Cut Off-Frequency Fixing Filters by Error Compensation of MAXFLAT FIR Filters." Electronics 10, no. 5 (February 26, 2021): 553. http://dx.doi.org/10.3390/electronics10050553.

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Maximally-flat (MAXFLAT) finite impulse response (FIR) filters often face a problem of the cutoff-frequency error due to approximation of the desired frequency response by some closed-form solution. So far, there have been plenty of efforts to design such a filter with an arbitrarily specified cut off-frequency, but this filter type requires extensive computation and is not MAXFLAT anymore. Thus, a computationally efficient and effective design is needed for highly accurate filters with desired frequency characteristics. This paper describes a new method for designing cutoff-frequency-fixing FIR filters through the cutoff-frequency error compensation of MAXFLAT FIR filters. The proposed method provides a closed-form Chebyshev polynomial containing a cutoff-error compensation function, which can characterize the “cutoff-error-free” filters in terms of the degree of flatness for a given order of filter and cut off-frequency. This method also allows a computationally efficient and accurate formula to directly determine the degree of flatness, so that this filter type has a flat magnitude characteristic both in the passband and the stopband. The remarkable effectiveness of the proposed method in design efficiency and accuracy is clearly demonstrated through various examples, indicating that the cutoff-fixing filters exhibit amplitude distortion error of less than 10−14 and no cut off-frequency error. This new approach is shown to provide significant advantages over the previous works in design flexibility and accuracy.

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Özdemir, Huseyin. "Two‐dimensional circularly symmetric filter design via coefficient mapping." GEOPHYSICS 54, no. 3 (March 1989): 392–401. http://dx.doi.org/10.1190/1.1442664.

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Two‐dimensional (2-D) filters are used in geophysics for processing seismic, potential field, and remotely sensed data, and in other applied sciences for purposes such as image processing. These filters can be designed using optimum one‐dimensional (1-D) algorithms via mapping techniques: the 2-D desired response is mapped into the 1-D response either in the time domain or the frequency domain and mapped back after an approximation is obtained. A coefficient mapping algorithm is presented here for designing 2-D circularly symmetric filters. The 2-D frequency‐domain coefficients are mapped to the 1-D frequency axis after being sorted according to their distances from the origin. This kind of sorting brings together the coefficients of a particular passband, reject band, or transition band of the circularly symmetric filter before the coefficients are mapped into the 1-D frequency axis. As a result, there are as many prescribed bands in the 1-D domain as in the corresponding 2-D domain, which leads to optimal approximations in the 1-D domain and, consequently, in the 2-D domain. The mapping is performed between the Nyquist regions. A Chebychev or “min‐max” algorithm has been used for 1-D approximations. Due to a complete mapping between the 2-D and the 1-D domains, the 2-D filters designed via mapping show equiripple behavior similar to that of the 1-D filters. The new mapping algorithm is suitable for designing low‐pass, high‐pass, band‐pass, and band reject filters with multiple bands. The circular symmetries of the approximated responses improve with an increased number of filter coefficients. For a 2-D filter with [Formula: see text] coefficients, [Formula: see text] and [Formula: see text] must be odd; but they need not be equal. Applications of low‐pass and high‐pass circularly symmetric filters to data from a regional gravity field survey demonstrate that these filters can effectively separate anomalies of different wavelengths when there is no spectral overlap.

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Melgarejo, J. C., J. Ossorio, A. A. San-Blas, M. Guglielmi, and V. E. Boria. "Space mapping filter design and tuning techniques." International Journal of Microwave and Wireless Technologies 14, no. 3 (October 25, 2021): 387–96. http://dx.doi.org/10.1017/s175907872100146x.

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AbstractA common strategy to reduce the cost of a filter is to use a manufacturing technique with an intermediate accuracy and use tuning elements to compensate for the manufacturing errors. However, including tuning elements in the final EM simulations, and tuning the filters after manufacturing, can be quite challenging. In this context, therefore, we review in this paper two powerful filter design procedures based on Aggressive Space Mapping (ASM), and two semi-automatic tuning techniques. As a validation, we describe in detail the design and tuning of two types of filters that are commonly used for both space and ground applications, namely, a six-pole inductive filter in rectangular waveguide, and a more complex five-pole filter based on dual-mode resonators.

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Mahmoodi, Sasan. "Scale-invariant filtering design and analysis for edge detection." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 467, no. 2130 (January 19, 2011): 1719–38. http://dx.doi.org/10.1098/rspa.2010.0475.

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Existing edge detection filters work well on straight edges but make significant errors near sharp corners by producing rounded corners. This is due to the fact that the edge maps produced by these filters are scale variant. We enhance Canny’s optimality criteria to incorporate detection performance near corners as an explicit design objective. The resulting optimal filter, termed ‘Bessel integral filter’, can be derived analytically and exhibits superior performance over recent alternatives, both in terms of numerical accuracy and experimental fidelity. A noise-free localization index is also derived here to account for the detection accuracy of discontinuities forming sharp corners in the absence of noise. We prove here that edges detected by the filters that are not optimal with respect to this noise-free localization index are scale variant. However, the Bessel integral filter proposed here is optimal with respect to the noise-free localization index and therefore it is a scale-invariant filter.

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Ehteshamuddin, Mohammed, Jebreel M. Salem, and Dong Sam Ha. "Design of High Temperature Combline Band-pass Filters for Downhole Communications." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2016, HiTEC (January 1, 2016): 000312–17. http://dx.doi.org/10.4071/2016-hitec-312.

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Abstract The decline of easily accessible reserves pushes the oil and gas industry to drill deeper to explore previously untapped wells. Temperatures in these wells can exceed 210 °C. Cooling and conventional heat extraction techniques are impractical in such a harsh environment. Reliable electronic designs that can sustain high temperature become necessary. This paper presents RF and IF microstrip combline band-pass filters for downhole communications, which can reliably operate up to 250 °C. Both filters are prototyped on a Rogers RO4003C substrate. Measured results at 250 °C show that the RF and IF filters have insertion losses of 4.53 dB and 3.45 dB, respectively. Both filters have stable performance at high temperatures. The maximum insertion loss variation with temperature for the RF filter is 1.88 dB, and bandwidth variation is 1.3 MHz. The maximum insertion loss variation with temperature for the IF filter is 1.48 dB, and bandwidth variation is 0.4 MHz. Return loss for the RF filter is more than 12 dB, and for the IF filter more than 10 dB in the passband. This paper also describes a simple method to find spacing between coupled symmetrical microstrip lines of a combline filter.

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Wu, Guoan, Siyuan Dong, and Qinfen Xu. "The Integrated Design of Power Dividerand Low-pass Filter." Frequenz 72, no. 11-12 (November 27, 2018): 517–21. http://dx.doi.org/10.1515/freq-2017-0206.

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Abstract A compact filtering Wilkinson power divider with harmonic suppression based on lumped components is presented in this paper. The new divider uses two 5th-order elliptic-function low-pass filters to replace the quarter wavelength microstrip lines of the conventional Wilkinson power divider. The structure combines the power divider and the filter into a complete device. By integrating elliptic low-pass filters with the power divider, the proposed structure can suppress harmonics due to the filter’s band-notched characteristic. The power divider demonstrates a measured suppression of 37.1 dB for the second harmonic, 36.6 dB for the third harmonic, 38.6 dB for the fourth harmonic respectively. The harmonic suppression is higher than 20 dB from 2.75 to 7.035 GHz. Furthermore, lumped components are utilized to achieve improvement on size reduction. Compared with the conventional divider, the proposed structure effectively reduces the size by 77 %. The insertion loss is 3.2 dB at the center frequency (1.45GHz).

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Joaquim, Marcelo Basilio. "Design of Low-Pass Active Filters Using Matlab." International Journal of Electrical Engineering & Education 35, no. 3 (July 1998): 274–78. http://dx.doi.org/10.1177/002072099803500309.

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In this paper a program developed in MATLAB programming language to aid in the design of all-pole active filters using operational amplifiers is presented. The filter structure chosen was the Sallen-Key that furnishes a filter with low sensitivity to element tolerances and it is easy to implement in hardware.

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Journal articles on the topic 'Filters’ design'

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