Abstract: Backwash process of sand filters requests specific surface velocity to reach the recommended filter bed height expansion, however the expansion of the filter bed height is very influenced by their characteristics. This work had as aim to evaluate the effect of different sand particle size, static filter bed layer and expansion of the filter bed height on a prototype of sand filter during backwash process. The tests were accomplished using a sand filterprototype that had structural similarity and shape as commercial equipments (24 cm of height and 12.7 cm of diameter). The treatments consisted from combinations of five separate sand particle sizes (0.15; 0.34; 0.51; 0.72 and 0.92 mm of medium diameter), five static filter bed layer (5; 7; 9; 11 and 13 cm) and different expansion of the filter bed height, with three replications. In general, the sand filterprototype was effective in characterizing with accuracy the backwash process, being possible using to obtain superficial velocity to reach specific filter bed height expansion using different sand particle sizes and static filter bed layer.
It is worth mentioning that using the same procedure, it can be shown that Eq. (17) holds for equal- ripple prototype lowpass ﬁlter regardless of the ripple value (see Appendix A). Although Eq. (18) does not hold for equal-ripple ﬁlters, Eq. (17) by itself is of great importance. It shows that the coeﬃcient of the second term in the denominator of S 21 (s) for both maximally-ﬂat and equal-ripple ﬁlters is only a
Electronic filter is circuit which perform signal processing functions, it is specially to modify, reshape, and remove unwanted frequency components from signal (Storr 2014). Electronic filter can be passive or active. There are many electronic filter such as, digital filter, FFT filter, low-pass filter, audio filter and lagging phase filter. These types of electronic filter have their own function. Digital filter has two general purpose is to separation of signal that have been combined, and restoration of signal that have been distorted in some way (Smith 1997). Otherwise, digital filter has two signal us e is signal separation and signal restoration. Signal separation is use when a signal has been contaminated with interference, noise or other signal and signal restoration is used when a signal has been distorted in some way, for example an audio is record with poor equipment will be filtered to better represent sound. FFT (fast Fourier transform) filter is a complicated algorithm and it a powerful tool to deal with the signal in the frequency domain. The frequency of input signal is analyzed by FFT filter and the required frequency components are selected (Jiao et al. 2015). Low-pass filter is a circuit offering easy passage to low frequency signal and passage to high frequency signals. This filter is design using operational amplifiers and low-pass filter are commonly used to implement antialias filter in data acquisition systems (Karki 2000).
In this section, the detailed procedures for designing the even-order Chebyshev bandpass filter are studied and given. The formulas of J -inverters studied in Section 2 will be the theoretical guidance in designing the bandpass filter. Two even-order Chebyshev bandpass filters with second- and fourth-orders are designed as examples to prove the derived theory in Section 2. These two filterprototype examples are designed and simulated, and the detailed design procedures and curves are given and discussed.
A simple and efficient method of prototypefilter design has been proposed that exploits spline function in the transition band of ideal filter. Prototypefilter is designed by new Cosh window and modified objective functions, application is being extended to CMFB and TMUX designs. With univariat unconstrained optimization different designs have been obtained and performance parameters are evaluated for two different spline function order. Simulation results show that proposed window based design are superior at spline function order = 1 in terms of aliasing distortion, ICI and ISI parameters. Amplitude distortion is comparable. It gives good fidelity assessment parameters when used for subband processing of the ECG and speech signal. Therefore it can be very effectively used in designing CMFBs and TMUXs.
to couple the input and output to the resonator as shown. Note that the chip capacitor package’s parasitic is relatively insignificant at low frequencies where the effect can usually be ignored. The filterprototype was fabricated on Roger RT Duroid 5880 substrate with a thickness of 787 µm and dielectric constant of 2.2. The inductive element is realized by a short circuit via hole shunted at the mid-point of the resonator. The dimension of the circuit is 7 cm × 2.8 cm.
Hentschel T. in paper  entitled “Channelization for software defined base-stations” proposed the Per-Channel (PC) Approach. It is based on a parallel arrangement of many one channel channelizers. The basic architecture of the PC approach is shown in figure 1. In figure 1, the order of channelization is filtering (H0(z) to Hn(z), digital down conversion (DDC), samp le rate conversion (SRC) and finally baseband processing (BBP).The filter, H0(z), is a low pass filter and all other filters, H1(z) to Hn(z)), are bandpass filters. It is possible to do digital down conversion followed by filtering and consequently, all the filters will be low pass filters (all filters are H0(z)). It is also possible to further reduce the complexity of the PC approach by employing polyphase decomposition of each of the filters and then moving the SRC to the left of filtering operation (i.e., performing SRC before filtering).By employing polyphase decomposition, the speed of filtering operation can be relaxed.
Assalamualaikum and greetings I start Muqadama. I want to first give thanks to the Almighty for by His permission me completing this Final Year Project which is title Analysis of Low Pass Filter Using Bowtie Defected Ground Structure at 10 GHz for Radar Application. This final year project report was prepared for Faculty of Electronic Engineering and Computer Engineering, Universiti Teknikal Malaysia Melaka (UTeM), basically for student in final year to complete the undergraduate program that leads to the degree of Bachelor of Electronic Engineering (Wireless Communication).
delay can always be obtained that ranges below the group delay of a corresponding LP FIR filter. However, the absolute minimum value of the passband group delay was of no concern. In contrast, for instance, Lang  has shown that his algorithms for the constrained design of digital filters with arbitrary magnitude and phase responses have the potential to achieve a considerable reduction of group delay as compared to LP FIR filters, even for high-order FIR filters. Moreover, several solutions to the problem of low-delay filter banks have been suggested in literature. In , an iterative method for the design of oversampling DFT filter banks has been proposed, which allows for controlling the distortion function for each frequency and jointly minimizes aliasing and imaging. The demand for low group delay particularly of the AFB prototype filters has not been asked for explicitly. Based on the algorithm  the approach  introduces additional constraints to the delay and phase responses. Noncritical decimation has also been suggested in , where both filter bank delay aspects and magnitude deviations of the distortion function have not especially been taken into consideration. In  the problems of aliasing eﬀect and amplitude distortion are studied. Prototype filters which are optimised with respect to those properties are designed and their performances are compared. Moreover, the e ﬀ ect of the number of subbands, the oversampling factors, and the length of the prototypefilter are also studied. Using the multicriteria formulation, all Pareto optimums are sought via the nonlinear programming technique. In  a hybrid optimization method is proposed to find the Pareto optimums of this highly nonlinear problem. Furthermore it is shown that Kaiser and Dolph-Chebyshev windows give the best overall performance with or without oversampling.
The MDFT filter bank proposed by Fliege belongs to time-invariant QMF filter banks. The channel number and subband filters do not change with time. In speech, audio and image processing, the time-varying filter bank can be used to adjust the input signal properties in order to get better processing performance [6, 7, 9, 10]. In the past, we have done a systematic research for the general time-varying filter bank including time-varying cosine-modulated filter banks [13–15]. In this paper, we want to use the established time- varying filter bank theory to analyze the time-varying MDFT filter bank (TV-MDFT), and investigate the properties of the MDFT filter bank in the case that its filter coe ﬃ cients change with time. We want to also study the prototypefilter design for a linear time-varying MDFT filter bank. After instruction Section 2 provides the description of the MDFT filter bank and its mechanism of aliasing error cancellation in both the time and frequency domain. Section 3 analyzes the time- varying MDFT filter bank including its PR condition and the relationship with time-varying cosine-modulated filter bank. In Section 4, the design of the prototype window filter for TV-MDFT is discussed. The well-know window switching method used in time-varying cosine-modulated filter bank  will be used in the prototype window design for TV- MDFT. Section 5 summarizes the main results of the paper.
higher order modes (evanescent mode) between adjacent FSSs must be considered and cannot be neglected. Therefore after designing of each FSS based on resonant-curve fitting separately based on equivalent circuit of closely spaced FSSs , we have to repeat optimization by calculating transmission characteristic of whole filter structure and using coupled-integral-equations technique (CIET).
Two-channel Quadrature Mirror Filter (QMF) bank is a multi-rate digital filter structure that consists of two decimators in the signal analysis section and two interpolators in the signal synthesis section. These filter banks were first used in sub-band coding, where the signal is split into two or more sub-bands in the frequency domain, so that each sub-band signal can be processed in an independent manner . QMF banks find applications in various areas, such as automated methods for scoring tissue microarray spots , image coding , multicarrier modulation systems , two- dimensional short-time spectral analysis , antenna systems , advances in sampling theory , biomedical engineering , wideband beam forming for sonar  and to solve co-existence problem of wireless communication systems [10, 11]. Related previous work on the design of Nearly Perfect-Reconstruction (NPR) two-channel QMF banks [12−27] can be classified into a number of different approaches.
is presented in this paper. The proposed resonator is ultra- compact in size compared to a traditional coaxial filter with similar unloaded Q-factor. The filter configuration based on the proposed resonator can further save size since no metallic housing is required as the external surface of H- shape resonator is silver plated. In addition, no screws or through holes at 45  is required for inter-mode coupling and self-coupling of each degenerate modes. Next, the bandwidth and center frequency of a 2 nd -order
Digital prototype is the main part of the process for complex product innovation and development. It is computer mathematical model of simulation which based on geometric model , and it can accurately and comprehensively reflect the characteristics of product appearance, function and behavior. Therefore, in recent years, digital prototype has gradually replaced the physical prototype to test product performance. Depending on the function, the digital prototypes contain structural prototypes, functional prototypes, structural and functional prototypes . The large- scale and high-complexity features in the design process make the digital prototyping system produce massive, high-dimensional and complex data. Therefore, the analysis of complex product digital prototype is still a difficult problem. At present, the research of digital prototype data of complex product is mainly based on engineering experience or independent qualitative analysis of single discipline, which lacks practical guidance significance.
Size reduction has becoming a major design consideration for practical applications in broadband wireless access communication system. As the size of the RF filter decrease, the application system will become smaller in size. Therefore, there is an increasing demand for low cost, light weight and compact size filters .
Abstract—Two ultra-wideband (UWB) microstrip bandpass filters (BPFs) are proposed by using tunable E-shaped dual-mode microstrip Stepped-Impedance Resonator (SIR). For the lower band filter measurement results show there is a passband of 3.1 GHz to 5.2 GHz and its 3 dB fractional bandwidth is 51%. The UWB upper band filter may be obtained by tuning E-shaped SIR. The measurement results show there is a passband of 6 GHz to 10.6 GHz and its 3 dB fractional bandwidth is 55%. Compared with the similar investigation using the cascade of electromagnetic band gap (EBG)-embedded multiple-mode resonator (MMR) and fork resonator, the proposed approach has some advantages, such as easier adjustment of bandwidths, better passband performances and smaller size etc..
Abstract—This paper investigates a combined Resonant- Repetitive (RR) control structure for a three phase four leg DC/AC converter power supply. The RR control configuration is composed by a resonant controller tuned at the system fundamental frequency working in conjunction with a plug-in type repetitive controller. The resonant part of the control scheme is used to assure prompt tracking of the inverter output voltage as well to achieve as fast as possible system response to load variations; to this purpose, it is tuned at the fundamental frequency. At the same time, the resonant controller is able to stabilize the system without the necessity of any further additional controller; the repetitive part of the scheme is implemented for the fine regulation at the system harmonic frequencies. The proposed control configuration is used to regulate the power supply output voltage providing very good tracking of the output voltage reference even in the presence of a non-linear load. Experimental validation from a 40 kVA converter prototype is presented to validate the operation of the proposed converter and control.
In recent years, ultrasonography is being used for effective diagnosis of various organs such as the heart, kidney, prostate, liver, ovary, uterus, thyroid glands etc. Unfortunately, one of its shortcomings is the low contrast, high noise images which are an inevitable byproduct. This is due to an artifact known as “Speckle” which obscures fine details in an image and may lead to erroneous diagnosis. Hence Speckle Filtering is a prerequisite in ultrasonography, provided that the features of interest for diagnosis are not lost. This paper presents a Hybrid and multistage Filtering approach in order to reduce the Speckle noise and improve the visual quality for better diagnosis. The performance of our approach is compared with the other Speckle reduction Filters on the basis of image quality parameters like Peak Signal to Noise Ratio (PSNR), Effective Number of Looks (ENL), Image Quality Index (IQI) and Mean Structure Similarity Index Map (MSSIM). We could achieve in Multistage approach a better performance with higher value of PSNR (79.915), IQI (0.9497), MSSIM (0.9945) and ENL (0.0984) compared to Hybrid Filter.
Findings strongly indicate that SAVs will, in the foreseeable future, face limita- tions and failures which in turn will require human intervention and remote control. Literature and case study analysis have confirmed the OOTL performance problem and loss of SK during teleoperations. A set of tasks and use-cases which remote op- erators could be faced with are identified. An assortment of prototype requirements are specified and translated into three low-fidelity interface concepts. From these concepts an exemplary HMD interface for SAV teleoperations has been developed. This work has found supportive evidence that using an HMD for SAV teleoperation provides a remote operator with superior advantages in comparison to a computer display. Findings from the prototype evaluations indicate that increased visibility, understanding and feelings of presence are effects associated with a remote operator using an HMD during teleoperations. These effects give an SAV remote operator a firm basis to combat their loss of perception and comprehension of elements in time and space as part of the OOTL performance problem. The study has also found that participants said that the use of an HMD would make them feel more confident and safe in comparison to a computer display. No statistically significant differences were observed based on a direct comparison between the HMD and com- puter display prototype. Results from the questionnaire indicate that the majority of subjects strongly supported the use of an HMD in future control rooms for tele- operations of SAVs. These conclusion underlines the relevance to consider the use of HMDs in the development of SAV teleoperation interfaces. The value regarding safety and reliability created by an HMD in SAV teleoperations can significantly foster the adoption of shared and automated mobility. However, any remote opera- tor, regardless of their Situation Knowledge should remain attendant to and careful for the safety and well-being of the passengers and significant other road users.