Showing papers on "Butterworth filter published in 2018"

An LCL -Filter Design With Optimum Total Inductance and Capacitance

Abstract: LCL -filter is among the best performing filters for grid-connected voltage source inverters Designing of the filter parameters (grid-side and inverter-side inductors and capacitor), takes an iterative approach due to the coherence between the parameters and design requirements such as IEEE-519 Std for harmonic current limitations, reactive power compensation limit, and maximum allowable voltage drop across the filter to limit the switching losses Most of the proposed LCL -filter optimization strategies emphasize on reducing the total inductance and losses of the filter while meeting the design requirements There is less emphasis given on the capacitor selection and optimizing its value Therefore, this paper proposes a method to compute the optimum capacitance requirement of the LCL -filter based on reactive power compensation of the filter rather than calculating it as a percentage of base capacitance of the filter as found in the literature The proposed design methodology compared to the previously proposed designs is capable of reducing filter capacitance by 50% while meeting the harmonic limitation demanded by IEEE-519 Std and also considers the impact of the total inductance on reactive power compensation Based on the proposed methodology an LCL -filter with minimum total inductance and capacitance is realized Functionality of the proposed LCL -filter is verified and validated through simulations and experimental results

Synthesis and Analysis of Electronically Adjustable Fractional-Order Low-Pass Filter

Abstract: A proposal of a fractional (1+α)-order low-pass filter is presented in this paper. The proposed filter operates in the current-mode and it is designed using Multi-Output Current Followers (MO-CFs), Dual-Output Current Follower (DO-CF), Dual-Output Adjustable Current Amplifier (DO-ACA) and Adjustable Current Amplifiers (ACAs) as active elements within the presented topology of the filter. The filter possesses ability to electronically control its order and also the pole frequency by changing the current gain of current amplifiers (ACAs) already present in the structure. Three different values of the order and pole frequency of the proposed low-pass filter were tested as an example. Design of the proposed filter is supported by simulation and experimental results. Simulations of the circuit are carried out in PSPICE simulator with behavioral models of used active elements. The experimental laboratory measurements are performed with the help of available devices forming equivalent circuits. Simulations and experimental results of the electronical control of the order and pole frequency are compared in this contribution.

An Integrated Machine Learning Algorithm for Separating the Long-Term Deflection Data of Prestressed Concrete Bridges

Abstract: Deflection is one of the key indexes for the safety evaluation of bridge structures. In reality, due to the changing operational and environmental conditions, the deflection signals measured by structural health monitoring systems are greatly affected. These ambient changes in the system often cover subtle changes in the vibration signals caused by damage to the system. The deflection signals of prestressed concrete (PC) bridges are regarded as the superposition of different effects, including concrete shrinkage, creep, prestress loss, material deterioration, temperature effects, and live load effects. According to multiscale analysis theory of the long-term deflection signal, in this paper, an integrated machine learning algorithm that combines a Butterworth filter, ensemble empirical mode decomposition (EEMD), principle component analysis (PCA), and fast independent component analysis (FastICA) is proposed for separating the individual deflection components from a measured single channel deflection signal. The proposed algorithm consists of four stages: (1) the live load effect, which is a high-frequency signal, is separated from the raw signal by a Butterworth filter; (2) the EEMD algorithm is used to extract the intrinsic mode function (IMF) components; (3) these IMFs are utilized as input in the PCA model and some uncorrelated and dominant basis components are extracted; and (4) FastICA is applied to derive the independent deflection component. The simulated results show that each individual deflection component can be successfully separated when the noise level is under 10%. Verified by a practical application, the algorithm is feasible for extracting the structural deflection (including concrete shrinkage, creep, and prestress loss) only caused by structural damage or material deterioration.

Constructing a Guided Filter by Exploiting the Butterworth Filter for ECG Signal Enhancement

Abstract: Electrocardiogram (ECG) signal enhancement is necessary in telemedicine. In such ECG monitoring systems, noises like muscle artifacts, electrode motion and baseline wander are often embedded in the ECG signals during acquisition and transmission. In this study, a novel method is proposed for the ECG signal enhancement based on the finding that ECG signals extracted over a big data share significant similarities in the morphology for a particular person. We construct a guided filter and reform it by a Butterworth high-pass filter. The Butterworth high-pass filter is utilized to remove the baseline wander. The advantageous edge-preserving guided filter is then applied to remove the rest noise, of which frequencies are between the ECG signals. Very promising results with high accuracy and the edge-preserving features have been achieved in the comparative experiments. We evaluated the proposed denoising method using ECG signals from the MIT-BIH Arrhythmia database and the Noise Stress Test database. The experimental results demonstrate that the proposed method achieves better signal-to-noise ratio (SNR) and lower root mean square error (RMSE) when compared to the wavelet with subband dependent thresholding (WT-Subband), Back Propagation Neural Network and Stockwell transform methods. Using the proposed method, the average output SNR ranges from 8.57 to 19.28 dB, and the average RMSE is less than 0.41.

Multiple-Sagnac-Loop Mach–Zehnder Interferometer for Wavelength Interleaving, Thermo-Optical Switching and Matched Filteri

Abstract: This theoretical modeling and simulation paper presents design and projected performance of an on-chip thermo-optical multi Sagnac loop Mach–Zehnder interferometer (MZI), operating at C-band and 3300 nm for silicon-on-insulator and germanium-on-silicon technological platforms, respectively. The MZI arms are comprised of an N -cascaded connection of Sagnac loop reflectors, each pair separated by a waveguide whose length is designed according to the wavelength-channel spacing requirements. N is chosen according to the Butterworth filter technique to provide one spectral response having maximal flatness within the desired bandwidth. Switched, spatial routing of odd and even channels is achieved by shifting the Through and Drop MZI spectra along the wavelength axis by means of a low-power thermo-optical heater stripe atop each loop-connector that changes its effective refractive index appropriately. We examined the SOI device performance for wavelength-division multiplexed wavelength (de)interleving. The analysis predicted good performance in terms of bandwidth, insertion loss, and channel isolation for 200, 50, and 25 GHz channel spacing. For the Ge-on-Si Sagnac MZI operating in the mid infrared, we showed that a comb filter is feasible whose lines exactly match the spectral signature of methane for trace-gas sensing applications.

Collaborative filtering model for enhancing fingerprint image

Abstract: Fingerprint enhancement plays a very important role in automatic fingerprint identification system. In order to ensure reliable fingerprint identification and improve fingerprint ridge structure, a novel method based on the collaborative filtering model for fingerprint enhancement is proposed. The proposed method consists of two stages. First, the original fingerprint is pre-enhanced by using Gabor filter and linear contrast stretching. Next, the pre-enhanced fingerprint is partitioned into patches in spatial domain, and then the patches are enhanced based on spectra diffusion by using the two-dimensional (2D) angular-pass filter and the 2D Butterworth band-pass filter. The proposed method takes full advantage of the ridge information and spectra diffusion with higher quality to recover the lost ridge information. To evaluate proposed method, the databases FVC2004 are employed, and the comparison experiments are carried out using various methods. Comparative experimental results show that the proposed algorithm outperforms the existing state-of-the-art methods on fingerprint enhancement.

Accurate integer-order rational approximation of fractional-order low-pass Butterworth filter using a metaheuristic optimisation approach

Abstract: This study presents a new approach to design fractional-order low-pass Butterworth filters (FOLPBF) in terms of integer-order rational approximations meeting an accurate magnitude response. A parameter-independent, metaheuristic optimisation algorithm called colliding bodies optimisation (CBO) is used for this purpose. The CBO-based optimisation routine determines the optimal values of the coefficients for the proposed integer-order models for the (1 + α), where, 0 < α < 1, order FOLPBFs. The performance of the proposed filter is examined concerning the passband and the stopband characteristics, solution quality robustness, and the convergence rate. The generic nature of the proposed design approach is also demonstrated. The roll-off characteristics of the proposed higher orders of FOLPBFs exhibit accurate stopband attenuation behaviour. The proposed designs also achieve the best magnitude responses as compared with state-of-the-art designs published in the recent literature. The proposed models can be practically implemented without using any fractance devices.

Simultaneous Measurement of Heart Sound, Pulse Wave and Respiration with Single Fiber Bragg Grating Sensor

Abstract: Heart sound, pulse wave and respiration are simultaneously measured with single fiber Bragg grating(FBG) sensor. The FBG sensor is inscribed in optical fiber so that it is quite thinner than conventional electrical sensor, even enough to be weaved in clothes. In this study, single FBG sensor is taped near the Tricuspid area and on the carotid artery with the surgical tape. Measured data is denoised through digital Butterworth filter with low pass filter (0.2 Hz), medium frequency band pass filter (0.5 Hz - 5.0 Hz) and higher frequency bandpass filter (35.0 Hz - 55.0 Hz) to extract the information of respiration, pulse wave and heart sound, respectively. The lower frequency signal follows the reference respiration sensor. The medium and higher frequency signal contains the features of typical pulse wave and heart sound waveform. The pulse wave measured on precordium contains the feature of apex cardiogram. The result also indicate that the timing of the heart sound is slightly delayed on the carotid artery. These results indicate the possibility of wearable, continuous vital sigh measurement system.

DXCCII-Based First Order Voltage-Mode All-Pass Filter

Abstract: In this article, a new design for realizing voltage-mode (VM) first order all-pass filter (APF) using single dual-X second generation current conveyor (DXCCII), one capacitor, one grounded resistor and one NMOS transistor operating in triode region is presented. The proposed circuit is analyzed for non-ideality presence due to voltage and current tracking errors and also due to parasitic components of the DXCCII to check the effect on functionality of proposed all-pass filter . PSPICE simulation and AD844 analogue IC-based experimental results are included to verify the proposed theory of the circuit.

Reconfigurable optical-microwave filter banks using thermo-optically tuned Bragg Mach-Zehnder devices.

Abstract: A new reconfigurable, tunable on-chip optical filter bank is proposed and analyzed for the silicon-on-insulator platform at the ~1550 nm wavelength. The waveguided bank is a cascade connection of 2 x 2 Mach-Zehnder interferometer (MZI) filters. An identical standing-wave resonator is situated in each MZI “arm.” Using the thermo-optic (TO) effect to perturb this waveguide's index, the TO heater stripes provide continuous tuning of the filter by shifting the resonance smoothly along the wavelength axis. To reconfigure and program the cascade array, a broadband 2 x 2 MZI-related switch is inserted between adjacent filters. The novel TO switch, described here, can provide either single or double interconnection of 2 x 2 filters. The filter resonator is a new in-guide array of N closely coupled phase-shifted Bragg-grating resonators that provide one resonant spectral profile with 5 to 100 GHz bandwidth. The length of each grating cavity in the N group is chosen according to the Butterworth filter technique, and this gives high peak transmission for the composite. The predicted spectral profiles of a three-stage cascade show two-or-three peaks, or two-or-three notches with movable wavelength-locations as well as tunable wavelength-separations between those features. A tunable notch within a wider movable passband is also feasible. Potential applications include microwave photonics, wavelength-selective systems, optical spectroscopy and optical sensing.

Comprehensive Study for Selection of Proper IIR Filter: Specifications Dependant Approach

Abstract: Filters are greatly used in signal processing and telecommunication engineering to eliminate the unwanted part of the signal i.e. noise. In modern years, filters are used in mobile communication for reducing the speech echo or in biomedical test (like Electrocardiogram, EEG etc.) to reduce the noise associated with the signal. Filters can be classified in two broad domains-Analog and Digital. The hierarchy involved in digital filters are further divided into two types-Infinite Impulse Response (IIR) and Finite Impulse Response (FIR). IIR filter are known for their infinite impulse response, there are various specification upon which the design depends, and all the techniques are used in different types of filter design. In this paper we have described the three main IIR filters i.e. Butterworth filter, Chebyshev Type I, Chebyshev Type-II. As the number of specifications are large, we should have a proper way to determine a specific filter for a particular application. In order to find the best suited filter, a specification dependent approach has been discussed which compares the parameters with respect to passband ripple, stopband attenuation, order of the filter and slope. and outputs the best filter suitable for a specific application. All the simulations have been carried out using MATLAB 2015-a and the algorithm has been coded using Python - high level programming language.

An 114 Hz–12 MHz digitally controlled low-pass filter for biomedical and wireless applications

Abstract: This study presents a wide tunable Gm-C low-pass filter for biomedical and wireless applications. The proposed filter was designed using the standard 90 nm complementary metal–oxide–semiconductor technology operating with a balanced supply voltage of 1.2 V. Modified linearisation techniques are used to improve the linearity of the digital programmable operational transconductance amplifiers (DPOTAs) which are used in the filter design. The proposed filter consists of three parallel fourth-order Butterworth sections. Each section is designed and optimised to target a specific band of frequencies. The operation of selecting between the different sections is free of any physical switches. Turning off the unwanted sections is utilised by setting the control bits of the corresponding DPOTAs to zeros. The performance of the proposed filter and DPOTAs is validated through simulation results. The third-order harmonic distortion of the DPOTA remains below −60 dB up to 0.5 V differential input voltage. The simulation results show that the digitally tunable cutoff frequency of the proposed low-pass filter is widely varied in the range of 114 Hz–12 MHz. The proposed filter achieves IIP3 of 28 dBm.

Design of Fractional Order Butterworth Filter using Genetic Algorithm

Abstract: This paper proposes the designing of fractional order low pass Butterworth filter using Genetic algorithm. The simulated magnitude response obtained using MATLAB is analyzed and verified at circuit level. The optimized results for the order 1.1, 1.5 and 1.9 are designed and verified using Tow Thomas biquad with SPICE simulations. Fractional order capacitor is used which is approximated using continued fraction expansion method. MATLAB and SPICE simulation results are compared for maximum attenuation in pass band. Good matching between MATLAB and SPICE results are achieved that shows the reliability of proposed filter.

Algorithm to Calculate Heart Rate and Comparison of Butterworth IIR and Savitzky-Golay FIR Filter

Abstract: Heart Rate is an important physiological parameter for health monitoring. Heart Rate measurement with smart phone is used by many people all over the world and different applications are developed. But, there are few issues behind the proper measurement like motion, baseline drift, power line interference, low amplitude PPG, and premature ventricular contraction and noise in the signal. While capturing red contact video of fingertips, miss touch errors can produce significant variation in real result as noise gets incorporated. Similarly, high pressure on camera and low pressure on camera can produce incorrect PPG signal and therefore, mislead to incorrect result. They can be treated as noise and needs to be removed up to a level to keep up the originality of a signal to give correct BPM rate. Here, in our study we have introduced an algorithm to get rid of certain percent of miss touch errors and thereby calculate heart rate from noise free signal, accurately. Here in our study, we have focused on Non-Invasive PPG signal based Heart Rate monitoring from skin blood flow using IR light at 900 nm wavelength. We have captured contact unfocused video to capture PPG using smart phone and developed algorithm to remove some percent of touch errors and followed by noise removal with 2nd Order Butterworth (IIR) band pass filter with frequency domain analysis and Hann Windowing for leakage reduction. We have also completed a comparative study in between Butterworth filter and Savitzky-Golay filter. The PPG is obtained from RED channel of the captured live video of smart phone camera.

Fully-differential current-mode higher order filters using all grounded passive elements

Abstract: In this paper the realization of nth order (n ≥ 3) fully-differential current-mode filters using Current Differencing Current Conveyors (CDCC) has been presented which results in circuits employing all grounded passive elements. In contrast to earlier known realizations of fully-differential filters which invariably require more than one capacitors per pole, the proposed realization employs only one capacitor per pole. The cut-off frequency of the realized filter can be electronically tuned when all the grounded resistors associated with the integrators are implemented by identical CMOS grounded voltage-controlled-resistors (VCR) driven by a common control voltage. The methodology has been illustrated by realizing a fifth order Butterworth filter as a specific example whose workability has been verified using SPICE simulations in 0.18 µm TSMC technology. A reduced-component-version of the designed fifth order Butterworth filter has also been presented which also employs all grounded RC components but does not have electronic-tunability. Some representative simulation results have been included.

A Study of the Effect of Integrating Low-Pass Filter in Measuring the Dynamic Performance of a High Speed 8-bit Analog-to-Digital Converter (ADC)

Abstract: This research focuses on integrating a low pass filter to the AD7575 DUT Board to measure its dynamic performance. The DUT Board integrated with the low-pass filter was attached to the ADI Family Board and was tested using the CTS5010 resources to measure the necessary dynamic performance parameters. The low pass filter was used to lessen the out-of-bound noise going into the ADC input that affects the measurement of dynamic performance of the ADC. Three active low pass filters were designed on the circuit board, namely Butterworth, Chebyshev and Bessel Filter. The integration of the filter showed significant change, with the Butterworth filter giving better measurement as compared to the other low-pass filters used.

Filtering of Noise in Audio/Voice Signal

Abstract: Filter plays a vital role in electronics and communication system. Filters are used to pass the desired frequency signals and rejects undesired frequency signal. There are several applications where digital filtering techniques are used such as data communication, voice or audio filtering, video processing, image processing and many more. The basic idea behind this paper is to design different types of infinite impulse response digital filters such as Butterworth filter (BWF), Chebyshev type I filter (CSFT-1), Chebyshev type II filter (CSFT-2) and elliptic filter (EF) and to compare their performance to find out best suitable type for the filtering of voice signal, using LabVIEW simulation.

Integrated On-Chip Bragg Time-Delay System for Thermo-Optical Control of a Microwave Antenna

Abstract: This theoretical modeling-and-simulation paper presents designs and projected performance of ∼1550-nm silicon-on-insulator beamsteering of a microwave phased array antenna by the use of true time delays. The tunable on-chip optical delay line is a cascade connection of waveguide Bragg grating resonators (WBGRs) separated by a piece of straight waveguide. The notch in the reflectivity spectrum is translated along the wavelength axis by means of a low-power TO heater stripe atop the grating, inducing a time delay that depends upon the line position of the WBGR affected by TO switching. The filter resonator is a new in-guide array of identical Bragg structures, each one comprising N closely coupled phase-shifted Bragg-grating resonators. The length of each grating cavity in an N group is chosen according to the Butterworth filter technique to provide one resonant spectral profile with 40 GHz optical bandwidth. Finally, we examined the performances of the beamformer system operating in the X and Ku bands, respectively. The investigation demonstrated that steering angles up to 48° are feasible by assuming a minimum steering angle of 8° and a minimum WBGR spacing of about 354 and 236 μ m for X and Ku bands, respectively.

Selection of the Band-Pass Range of the Normalizing Signal Transducer of the Sensing Element in the Instrumentation and Control Systems

Abstract: In automatic control systems (ACS), the unifying (normalizing) converter (UC) of the physical magnitude sensor amplifies the signal of the sensing element (SE) to a standard value. In this case, the band-pass range of the UC specifies the value of signal delay time of the SE in the UC. It is shown that the dynamic error of the UC is determined by the signal delay time of the SE and the first derivative of the SE. The response of the UC was approximated by the Butterworth filter response. The use of the Filter Solution application programs in the NI Lab VIEW software environment (Lab View 8.6) enabled to obtain the numeric evaluations of the signal delay time of the SE in the UC. It is shown that for the case of an infinite spectrum the first signal derivative of the SE does not differ from the value obtained with the Bernstein inequality. The final calculations showed a significant effect of the dynamic error on the total error of the sensor, which causes the increase tenfold the band-pass range of the UC in comparison with the signal band of the UC.

Performance Study of Neural Network Unscented Kalman Filter for Denoising ECG Signal

Abstract: The aim of this paper is a removal of noise from electrocardiogram (ECG) signals. A dual unscented Kalman filter based on multilayer perceptron (MLP) has been proposed for removing the artificial white, colored Gaussian noises and non-stationary muscle artifact from ECG signals. The (MLP) is used as the nonlinear functional form of the unknown model. Dual Unscented Kalman filter (UKF) is used for the part of the algorithm that estimates the clean state and the weights of the network. The obtained results are compared with other enhancement conventional filters, such as, normalized least mean square (NLMS) and Butterworth filter (BF). The quantitative study of output of the different methods has been presented based on mean squared error (MSE), signal to noise ratio (SNR) and peak signal to noise ratio (PSNR). By considering these parameters, the experimental comparative analysis has shown that the UKF-MLP had optimal performance and capability than conventional filters for denoising ECG signal.

Chained-Function Filter Synthesis Based on the Legendre Polynomials

Abstract: A new kind of filter called Legendre chained-function (LCF) filter with characteristic function given by the product of low-degree Legendre orthogonal polynomials (seed functions) is studied in this paper. LCF filter magnitude response exhibits unequal ripple level in the passband compared to Chebyshev chained-function filter with identical edge ripple factor at the passband edge. A proper combination of seed functions, i.e., a product of them, is used to control the maximum ripple in the passband, which affects the return loss, selectivity and a group delay characteristics of a filter. By selecting one of the possible combinations of seed functions (thus obtaining various degrees of freedom in filter design), filters with improved performances compared to traditional approximation techniques can be obtained. The degrees of freedom increase if the degree of filter increases. Compared to existing Chebyshev chained-function (CCF) filters, whose performances are also presented, and Butterworth function filters as a special case of both LCF and CCF filters, the new family of LCF filters has many advantages. A table summarizing properties of CCF and LCF filters is given for design purpose.

Online Wavelet Complementary velocity Estimator

Abstract: In this paper, we have proposed a new online Wavelet Complementary velocity Estimator (WCE) over position and acceleration data gathered from an electro hydraulic servo shaking table. This is a batch estimator type that is based on the wavelet filter banks which extract the high and low resolution of data. The proposed complementary estimator combines these two resolutions of velocities which acquired from numerical differentiation and integration of the position and acceleration sensors by considering a fixed moving horizon window as input to wavelet filter. Because of using wavelet filters, it can be implemented in a parallel procedure. By this method the numerical velocity is estimated without having high noise of differentiators, integration drifting bias and with less delay which is suitable for active vibration control in high precision Mechatronics systems by Direct Velocity Feedback (DVF) methods. This method allows us to make velocity sensors with less mechanically moving parts which makes it suitable for fast miniature structures. We have compared this method with Kalman and Butterworth filters over stability, delay and benchmarked them by their long time velocity integration for getting back the initial position data.

Maximum Torque Increase and Performance Optimization for Induction Motor Field-Weakening Control

Abstract: This paper proposes a fundamental voltage equivalent principle-based over-modulation algorithm to increase the maximum output torque for induction motor (IM) field-weakening control. By using the proposed approach, the hexagon voltage vector can be achieved, leading to optimized dc-link voltage utilization. Besides, the phase delay in voltage vector is avoided by using a circle-type reference. To further eliminate the influence of the harmonics on the current regulator, a Butterworth filter is adopted to filter out the harmonic components in the feedback current. The experimental results verify the effectiveness of the algorithm.

Butterworth re-fading Rayleigh channel simulation method

Abstract: Disclosed is a Butterworth re-fading Rayleigh channel simulation method. The method comprises the steps of firstly, simulating a Butterworth re-fading Rayleigh channel via a computer, and verifying the Butterworth re-fading Rayleigh channel, mainly comprising the following steps: initializing parameters including maximum Doppler shift, system sampling frequency, system sampling point number N andButterworth filter related parameters, then generating the Butterworth re-fading Rayleigh channel, inputting two paths of Gauss white noise to a Butterworth filter, generating colored Gauss white noise sequences with Butterworth Doppler power spectra respectively, and composing a real part and an imaginary part of the Butterworth re-fading Rayleigh channel respectively; and finally, performing first-order and second-order statistical analysis on the Butterworth re-fading Rayleigh channel, and then designing a channel hardware simulation system. By adopting a shaping filter, i.e., the Butterworth filter, the Butterworth Doppler power spectra of the Rayleigh channel are convenient to realize, and the envelope conforms to Rayleigh distribution.

Command current detection algorithm based on Kalman filter

Abstract: The detection algorithm of compensation current command signal is one of the key technologies of power quality regulator. The real time nature of the detection algorithm affects the effect of compensation. Conventional i p– i q detection algorithm is commonly filtered by Butterworth filters. However, its inherent delay characteristics make the detection real-time poor. In order to improve the real-time of the detection algorithm, this paper proposes an i p– i q detection algorithm based on Kalman filter. First, Establish equations of state and measurement for the Kalman filter based on i p– i q . Then, the Kalman filter algorithm is used to filter i p– i q to obtain DC component, inverting the DC component to obtain the three-phase fundamental current. Finally, the proposed algorithm is simulated by matlab and compared with the algorithm which using Butterworth filter. The results show that the proposed algorithm is better than the latter in real-time.

A New Design of Quasi-Elliptic High-Low Microstrip Lowpass Filter Using SC-Defected Ground Structure Technique

Abstract: This paper proposes for microwave communication areas a new design of Quasi-Elliptic High-Low Microstrip Lowpass Filter (QE-HL-MLPF) based on a Semicircular Defected Ground Structure (SC-DGS). The filter design employs a new technique of cascading high (Hi) and low (Lo) impedance elements in simulating the ladder LC lumped-circuit prototype. MATLAB and full wave electromagnetic simulator are used to model the proposed design and extract the scattering parameters. A semicircular-shaped resonator is implemented into the 4th order Butterworth filter structure which uses a Quasi-Elliptic function as a systematic design process, providing a sharp roll-off at 2.5 GHz, good rejection of less than −30dB up to 3 GHz, and low return loss of approximately −20dB over the entire filter passband. The filter parameters show interesting insertion loss of −3.025dB at a cut-off frequency equals to 1.53 GHz, and wide stopband with efficient harmonics suppression for more than 2 GHz from the cut-off frequency.