Chebyshev Low-pass Filter Research Articles

Designing of CCII-Based Fractional Order Inverse Chebyshev Filters Using Gray Wolf Optimization Approach

The paper introduces a new approach for designing fractional-order inverse Chebyshev low-pass filters (FOICLF), with an emphasis on filters with an order of 1+α. The coefficients for these filters are determined through Gray Wolf Optimization by approximating filter response with the ideal response of same order FOICLF. Stability tests are conducted, and filters are implemented using Multiple Input Single Output topology with commercial ICs. Comparative analysis reveals close proximity between the ideal response of FOICLF and the designed filters, featuring maximum and mean square errors of –22.48 dB and –61.07 dB, respectively, for 1.7 order. Results are benchmarked against existing literature, highlighting superior performance in stopband and passband magnitude errors and stopband attenuation. Process, Voltage, and Temperature analysis assesses the impact of the parameter variations on the –3 dB frequency, assuring the robustness of designed filters with relative standard deviations ranging from 0.003% to 3.013% for the 1.7 order filter.

0.5 V Multiple-Input Fully Differential Operational Transconductance Amplifier and Its Application to a Fifth-Order Chebyshev Low-Pass Filter for Bio-Signal Processing.

This paper presents a multiple-input fully differential operational transconductance amplifier (MI-FD OTA) with very low power consumption. To obtain a differential MOS pair with minimum supply voltage and minimum power consumption, the multiple-input bulk-driven MOS transistor operating in the subthreshold region is used. To show the advantage of the MI-FD OTA, a fifth-order Chebyshev filter was used to realize a low-pass filter capable of operating with a supply voltage of 0.5 V and consuming 60 nW at a nominal setup current of 3 nA. The proposed filter uses five MI-FD OTAs and five capacitors. The total harmonic distortion (THD) was 0.97% for a rail-to-rail sinusoidal input signal. The MI-FD OTA and the filter application were designed and simulated in the Cadence environment using a 0.18 µm CMOS process from TSMC. The robustness of the design was confirmed by Monte Carlo analysis and process, voltage, and temperature corner analysis.

Nature inspired algorithm based design of near ideal fractional order low pass Chebyshev filters and their realization using OTAs and CCII

Fractional order filters offer greater freedom of design and a precise control over stopband attenuation in electronic circuits and systems. This paper presents the design of a fractional order low pass Chebyshev filter (FOLCF) that achieves near-ideal response characteristics. The methodology introduced utilizes metaheuristic optimization methods, including particle swarm optimization, firefly algorithm, and grey wolf optimization. These techniques are employed to precisely adjust the filter coefficients for the orders (1+α), (2+α), and (3+α). The adjustment is carried out by comparing the desired behaviour of the FOLCF with generalized fractional order low pass transfer functions. Throughout these instances, the parameter α is varied within the range of (0, 1). The designed filters are then tested and compared on the basis of various factors. Simulation results demonstrate that the designed filters closely follow the behaviour of an ideal Chebyshev filter with maximum passband and stopband magnitude errors being −31.93 dB and −52.74 dB respectively for (1+α) order filters. These values for (2+α) and (3+α) order FOLCF have been observed to be −30.04 dB and −55.91 dB; −17.72 dB and −49.52 dB respectively. Furthermore, it has been observed that the proposed work outperforms existing state-of-the-art approaches in various aspects, including magnitude error, stopband attenuation, and cut-off frequency. The stability of the designed filters has been verified through stability analysis. Additionally, practical feasibility of the proposed FOLCF is demonstrated through SPICE simulations for α = [0.2,0.5,0.8] using second generation current conveyor (CCII) and operational transconductance amplifier (OTA) based topologies while approximating the constant phase element using fifth order continued fraction expansion. The SPICE implementations closely follow the behaviour of ideal filter with −48.67 dB and −62.8 dB as mean square errors for CCII and OTA circuits respectively, showcasing the proposed filters' superiority and practical applicability in advanced electronic design.

Millimeter-wave low-loss on-chip metamaterial for 5G communication based on non-periodic composite right-/left-handed transmission line

This Letter reports a millimeter-wave low-loss on-chip metamaterial based on a concept of a non-periodic composite right-/left-handed (CRLH) transmission line (TL). Compared with a classic periodic unit cell, a non-periodic CRLH TL is proposed to obtain higher transmittance and better reflectivity. First, based on the CRLH TL theory, the LC values of the periodic transmission line were calculated. Second, Ti factors were derived using Chebyshev low-pass filter prototypes and the bandpass transformation theory. Third, these values were then used to calculate the factors of the non-periodic structure, which was eventually implemented using lumped elements. By analyzing the dispersion property, the proposed non-periodic CRLH metamaterial features both right-handed (forward wave) and left-handed (backward wave) propagating modes, which accounts for its wide bandwidth. For demonstration, a gallium arsenide-based integrated passive device process is adopted. As its main advantages, the fabricated metamaterial shows a high and flat transmission with minimum insertion loss of 0.68 dB at 30.2 GHz, and a low reflectivity better than −10 dB from 14 to 51 GHz of which the fraction bandwidth is over 120%.

Coaxial Low-Pass Filter Design and Manufacture

In this study, a low-pass filter with coaxial transmission lines is designed and produced. The objective for designing a coaxial low-pass filter was to utilize both low loss transmission and high breakdown voltage capability for high power microwave applications to enable the suppression of the second harmonic of the 4.4-6 GHz C-Band ( C-Band was selected as a proof of concept ) signals with minimal insertion loss. Microwave and 3D electromagnetic simulators were used in the filter design. The design was started by establishing an 11 th order Chebyshev low-pass filter prototype giving 0.05 dB ripple. Based on this prototype, a filter circuit consisting of capacitors and inductors as lumped elements was designed. The low and high impedances to be selected for the stepped impedance method, which is the basis of the transition to coaxial transmission lines, were decided and the most suitable impedances for manufacturing was determined. The filter using these impedances and designed with stepped impedance lines was transformed into the filter in which coaxial transmission lines are used. Coaxial transmission lines in the low-pass filter circuit consist of conductors with an insulating material in between. While the insulating material is selected as air in the high impedance sections of the transmission lines, it is PTFE (Polytetrafluoroethylene) with an insulating constant of 2.1 in the low impedance sections. The designed filter was manufactured. The basic properties of the manufactured filter were characterized by using RF measuring devices and compared with the designed filter. The measurements results prove that the frequency responses of the designed filter and the produced filter are very close to each other. Namely, a low-pass filter with a cutoff frequency of 6 GHz, a sharp suppression of about 45 dB at the stopband of 9 GHz and a return loss of 20 dB was designed and produced by using coaxial transmission lines. The novelty in our work can be stated that the power handling capability is increased by two techniques. The first one is that the highest transmission line radius preventing the higher order mode excitations is used to decrease the conductor loss. Teflon is covered around the low impedance lines to enhance the dielectric breakdown capability. Teflon inclusion is also used to decrease the practical low impedance level that improves the filter characteristics.

Electro-optic power/signal quality optimization based on the interaction between electro-optic modulators and electrical filters

Abstract This paper clarifies the effects of electrical filters with electro-optic modulators variations on the power/signal quality optimization and minimum data error rates reduction. The electro-optic modulators that are namely Mach Zehnder modulator, absorption modulator measured, single-drive Mach Zehnder modulator measured, and electro-absorption modulator. In addition to the filters are employed low pass (LP) Gaussian filter, LP Bessel filter, LP Butterworth filter, and LP Chebyshev filter. The hybrid combination between these modulators at the Tx. and the filters at the Rx. side give the chance to set the best candidate combinations from these devices for the power and signal quality optimization.

The Design and Simulation of a Fifth-order Chebyshev Low-Pass Filter

Chebyshev filter is a design classification of filters. It uses the Chebyshev transfer function, and has many filter types, such as high-pass, low-pass, band-pass, high-resistance, band-stop and so on. Compared with the Butterworth filter, the transition band of the Chebyshev filter is very narrow, but the internal amplitude-frequency characteristics are unstable [1][2]. Chebyshev filter achieves complex transmission zeros to improve the group delay characteristics in the pass band and reduce the signal distortion. In the process of designing a five-order Chebyshev filter, an active filter network needs to be established, and each stage of the low-pass filter composed of an amplifier is connected in the same cascade to form a multi-order Chebyshev low-pass filter. To design a Chebyshev filter, a Sallen-key structure is needed, and the transfer function is determined according to the position and size of the different resistors and capacitors placed, and a Chebyshev filter with different functions is constructed. The Multisim Simulation software is used to simulate the design results, and the frequency response amplitude curve in the image is found to be fluctuating with equal ripple in the pass or stop band.

Quasi-Isotropic Hybrid Dielectric Resonator Antenna—Bow-Tie Patch with Harmonic Suppression

This paper proposes a quasi-isotropic hybrid dielectric resonator antenna (DRA) and bow-tie patch with harmonics suppression. The suggested antenna consists of a DRA, a bow-tie patch, and a microstrip seventh-order Chebyshev low-pass filter. By loading a bow-tie patch on the designed DRA, a quasi-isotropic pattern is realized. The seventh-order Chebyshev low-pass filter was applied to the feed line, and harmonics were reduced in the section separate to the operating band to remove harmonics generated by the proposed antenna. The simulated S11 that satisfies below −10 dB is 3.09–3.3 GHz (6.25%), and the measured S11 is 3.10–3.28 GHz (5.64%). The simulated gain difference considering all radiating regions (0∘≤φ≤360∘ and 0∘≤θ≤180∘) is 7.211 dB. Compared with the antenna without a filter, the harmonic gain was reduced by 10.847 and 15.774 dB. The measured gain isolation of the operating band and the second and third harmonics are 10.10 and 18.94 dB, respectively. The proposed antenna is considered to be applicable to applications that require radio wave reception in all directions such as wireless point access points, internet of things and radio frequency identification, and is expected to contribute to reducing the size of the RF system.

Optimization design of fractional‐order Chebyshev lowpass filters based on genetic algorithm

AbstractFractional‐order filters have received extensive attention from international scholars because of their greater design freedom and continuously stepped stopband attenuation rate. Based on genetic algorithm (GA), this paper proposes an optimum design approach for fractional‐order Chebyshev lowpass filters that meet design specifications. The fractional order and ripples attenuation of the normalized Chebyshev lowpass filter are calculated according to specifications, the integer order in the Chebyshev polynomial is replaced with the calculated fractional order, and then the fractional‐order Chebyshev polynomial is substituted into the magnitude response of the normalized Chebyshev lowpass filter along with the ripples attenuation to achieve the ideal response. The transfer function parameters of a fractional‐order filter are optimized using GA to make the magnitude response approximate the ideal response described above. This completes the optimized design of a fractional‐order Chebyshev filter that meets specifications. Given three different sets of design specifications, the fractional‐order Chebyshev filter designed using the proposed method is compared with one designed by another method in the literature. Finally, design examples are presented, stability analysis and Pspice simulations are performed, and an actual circuit is constructed to illustrate the effectiveness of the proposed method.

CBFMCycleGAN-VC: Using the Improved MaskCycleGAN-VC to Effectively Predict a Person’s Voice After Aging

One task of nonparallel speech conversion is to convert the source speaker’s speech samples to the target speaker’s speech samples, keeping the content unchanged. In view of the advantages of MaskCycleGAN-VC in nonparallel speech conversion, such as small model size and superior performance, our paper uses the basic structure of MaskCycleGAN-VC to improve it and proposes a cyclic boundary method filling in the frame MaskCycleGAN-VC (CBFMCycleGAN-VC) model, which predicts the voice of a person as he ages by using voice samples of his younger self. First, this paper adds speech preprocessing modules, including the Chebyshev low-pass filter and adaptive filter, which increases the robustness of the system. Second, our paper considers the time-domain difference in the weight parameters, which makes it easier to grasp the mapping law of the time-domain structure, with a faster convergence speed. Last, the circular boundary method is introduced to avoid the ringing effect, to enhance the connection between the filled frame and the adjacent frame, and to obtain a better generator. The simulation results show that the CBFMCycleGAN-VC model is more suitable for the speech conversion task of predicting the voices of elderly people, and the convergence speed is faster. The converted voice is also closer to the voice of the target speaker in the time domain and frequency domain. Under the condition that the accuracy rate is similar to that of MaskCycleGAN-VC, the MOS score is 17.5% higher than that of MaskCycleGAN-VC.

−52 dBm 수신 감도를 갖는 900 MHz 대역 Wake-Up 수신기 설계

This paper describes the results of manufacturing and measuring low-power wake-up receiver (WuRx) modules operating in the 900 MHz band using the AS3933 amplitude shift keying (ASK) receiver chip. The RF envelope detector has the advantage of low power consumption, but it has the disadvantage of low sensitivity. Therefore, this study designed the WuRx by applying antenna impedance matching circuits, envelope detectors with voltage doubler structure, LC filters in the form of removing ripples, and the 5th-order Chebyshev low-pass filters to increase sensitivity while maintaining low-power conditions. A 3.3 V single supply was applied to the WuRx, and the test result demonstrated −52 dBm sensitivity with 1 % packet error rate (PER) under the current consumption of 619 μA and the data rate of 2.52 kbps.

IPD-Based Miniaturized Wideband Bandpass Filter With Frequency-Dependent Complex Source and Load

In this article, an ultraminiaturized bandpass-filtering matching network based on GaAs substrate integrated passive device (IPD) technology is proposed, which is suitable for frequency-dependent complex source and load. The presented bandpass filter (BPF) is derived from an equal-ripple Chebyshev low-pass filter prototype through frequency transformation and impedance scaling. The susceptance required by the source and load is extracted from the adjacent susceptance blocks, and the final reactance/susceptance block is equivalent to a series/parallel LC circuit at the two edge frequencies. Therefore, the proposed design has both bandpass high-selectivity and impedance matching functions, and simultaneously, the bandwidth can be flexibly controlled. Finally, a wideband BPF example with the center frequency of 3.5 GHz was simulated and fabricated with the IPD process, showing satisfactory performances.

An Optimal Framework for WDM Systems Using Analytical Characterization of Refractive Index-Related Nonlinear Impairments

Nonlinear effects in the optical transmission systems (OTSs) are considered as the major performance limiting factor to provide high transmission rates over ultra-long distances. As the demands for system capacity, transmission range and the number of users is increasing exponentially with the development of mobile broadband, new challenges are being faced by the backbone optical networks. Mainly, the refractive index related non-linearities (RIrNLs) need to be characterized to design an optimal OTS for error-free transmission with provision of wavelength division multiplexing (WDM) to support for multiple channels. This paper provides an estimation technique of RIrNLs for long-haul transmission and their treatment for different channel spacing and the number of channels in a WDM system operating frequency domain multiple in multiple out (FD-MIMO) equalizer based digital signal processing (DSP) receiver and microstrip Chebyshev low pass filter. The main focus of this work is to utilize the existing structure of OTS for RIrNLs treatment with a low cost solution. Thus, by varying the parameters of the third order dispersion parameters, group velocity dispersion parameters, phase modulation dispersion and nonlinear refractive index, the impact of RIrNLs is investigated in detail to enhance the transmission range and capacity of the current OTS. The proposed system is analyzed in terms of range of input power, fiber length and received power for OTS figure of merits including bit error rate (BER) and optical signal-to-noise ratio (OSNR). Using duo-binary modulation, the BER achieved in this work is <10−5 till 500 km range, for maximum number of 32 channels, with 100 Gbps aggregate data rate, which shows the feasibility and effectiveness of our proposed model.

GENERAL STRUCTURE OF INTEGRATOR-BASED CONTINUOUS-TIME ACTIVE-RC FILTER AND APPLICATIONS

In the paper, a general structure of integrator-based continuous-time Active-RC filter is presented. More specifically, filter structures containing inverting amplifiers and passive feedback network are considered. The structure is analyzed using matrix description. The extensions of the model that take into account finite DC gain and finite bandwidth of operational amplifiers as well as other non-ideal effects are presented. The matrix-based approach is formulated especially for efficient use in computer analysis and design of Active-RC filters. An application example of the proposed approach to obtain OPAMP specifications for 3rd order low-pass Chebyshev filter for Analog Front End for VDSL is given. In this paper, we consider a general Active-RC filter topology suitable for computer-aided analysis, design and optimization of Active-RC filters. The structure is not the most general one, since it is restricted to filter topologies containing only inverting amplifiers (especially integrators) and RC feedback network.

A 3rd/5th Order Active RC Chebyshev Analog Baseband Low-Pass Filter With Reconfigurable Bandwidth and Gain

The design of 3rd/5th order active RC Chebyshev low-pass filter (LPF) with reconfigurable bandwidth and gain is based on 55 nm CMOS technology. The filter is integrated into draft IEEE 802.11ax concurrent dual band four antenna transceiver analog baseband circuit. Programmable capacitor bank of the filter is used to adjust bandwidth. The typical bandwidth of receiving filter is 10/20/40 MHz, and that of transmitting filter is 12/24/50 MHz. Adjust the gain ranging from -10 to 18 dB in passband by programmable resistor bank. The current consumption of typical bandwidth of receiving filter is 2.08 mA at a 1.5 V supply and has properties of 10 MHz bandwidth (BW), 36 dB gain, -62 dBm input signal, -39 dB third intermodulation distortion (IMD3), 17.1 nV/√Hz equivalent input noise (EIN). As for transmitting filter, the current consumption of typical bandwidth is 1.25 mA at a 1.5 V supply and has the properties of 10 MHz BW, -6 dB gain, 0 dBm input signal, -38 dB IMD3, 75 nV/√Hz EIN. Area of the whole filter is 0.08 mm2.

Design of high-performance microstrip and coplanar low-pass filters based on electromagnetic bandgap (EBG) structures

In this paper, a rigorous method for the design of high-performance n-order Chebyshev low-pass filters based on electromagnetic bandgap (EBG) stepped impedances in microstrip and coplanar (CPW) technologies is proposed. Fifth-order low-pass filters implemented by means of circular patterns etched in the ground plane of microstrip and CPW lines have been designed, simulated and measured on an RO3010 substrate (∊r= 10.2, tanδ = 0.0023 at 10 GHz, substrate thickness h = 0.635 mm and copper thickness t = 0.018 mm). The designed filters have shown a good agreement between EM simulation and measurement results. The proposed EBG-based low pass filters, with six etched circles and a size of 42 × 20 mm2, achieve a passband with a cut-off frequency fc = 6 GHz measured at |S11| = −20 dB, return loss RL = 20 dB, 5 reflection zeros in the frequency axis, a ripple lower than 1.1 dB, and a stopband greater than 5 GHz with a rejection level higher than 30 dB. Therefore, the designed low-pass filters have an ultra-wide passband with high return loss, low insertion losses and a low ripple. In addition, they exhibit a large stopband with high rejection level compared to other reported wide stop-band low-pass filters based on EBG, defected ground structures (DGS), or modified complementary split ring resonators (CSRR). This technique can be used to design high-performance Chebyshev EBG-based low-pass filters with a high degree of control over the characteristics of their frequency responses. This allows to replace the EBG-, DGS- and CSRR-based wide stop-band low-pass filters in microwave circuit and antenna applications, with filter structures exhibiting high return loss, equiripple responses in the passband, and high rejection level in the stopband.

The design of multiple feedback topology Chebyshev low-pass active filter with average differential evolution algorithm

This study presents the design of a tenth-order multiple feedback Chebyshev low-pass filter (MF-C-LPF). Component selection and gain calculation of filters are generally achieved over long periods of time using traditional methods. For 1-dB and 3-dB gains, the component values of the filter were optimized for both continuous and discrete values using four different metaheuristic algorithms. In the first case where continuous values were used, component values were accepted as ideal and unlimited in order to minimize gains. In the second case, industrial E196 series component values were used to transform the design problem into a discrete optimization problem. In this case where the design problem became more complex, the performance of the metaheuristic algorithms was compared. The literature review shows that this study is the first attempt to design a 10th-order MF-C-LPF for E196 series values. The average differential evolution algorithm is proposed to determine the optimal component values of the tenth-order MF-C-LPF. The performance of the proposed method was compared with three commonly used algorithms (PSO, CSS and DE). The optimal filter component values and quality factors (Q) were presented for each stage. We believe that the quality factor values will be a reference for future studies.

Design of a Wide-Band Microstrip Filtering Antenna with Modified Shaped Slots and SIR Structure

This paper presents a new compact microstrip filtering antenna with modified shaped slots to improve the impedance bandwidth. The proposed microstrip filtering antenna consists of three parts: the monopole radiating patch antenna; the Stepped Impedance Resonator (SIR) filter; and the feeding microstrip line. The designed structure is achieved on one-sided glass epoxy FR-4 substrate with dielectric constant εr = 4.4 and thickness h = 1.6 mm. The design procedure of the proposed filtering antenna starts from the second-order Chebyshev low pass filter (LPF) prototype. The achieved results show an excellent performance of S11-parameter with broadside antenna gain on +z-direction. Having two transmission zeros at 5.4 GHz and 7.7 GHz, good skirt selectivity and a wide-band impedance bandwidth of about 1.66 GHz makes the designed filtering antenna suitable for high-speed data communications. Both the simulation results generated by using the Computer Simulation Technology (CST) software package and the measurement achieved by using a vector network analyzer (HP 8510C) and the anechoic chamber show good agreement.

Analog Circuit Fault Detection by Impulse Response-Based Signature Analysis

This paper presents a method for the detection of parametric faults in linear filters with the help of impulse response which is studied on the basis of cross-correlation, a statistical metric. Impulse input is generated with delay flip flops and R–C circuit with minimum circuit complexity. Cross-correlation of impulse responses of the faulty and non-faulty circuits is fitted with Gaussian function. Component tolerances are mapped to statistical metric spaces in terms of Gaussian fitting parameters by Monte Carlo simulation. The proposed method is validated with simulated (using UMC-180 nm technology in CADENCE Virtuoso platform) as well as experimental results. Two benchmark analog filter circuits, second-order Sallen–Key band-pass filter and fourth-order Chebyshev low-pass filter, are considered as test circuits. The present method requires minimum circuit complexity and computational effort. The proposed fault detection technique is applicable for any linear analog circuit.

Design and optimization of microstrip filtering antenna with modified shaped slots and SIR filter to improve the impedance bandwidth

This paper presents a new compact microstrip filtering antenna with modified shaped slots to improve the impedance bandwidth. The proposed microstrip filtering antenna consists of three parts; the monopole radiating patch antenna, the SIR filter, and the feeding microstrip line. The design structure is achieved on one sided glass epoxy FR-4 substrate with dielectric constant e_r = 4.4 and thickness of h = 1.6 mm. The design procedures of the proposed filtering antenna starts from the second order Chebyshev low pass filter prototype. The simulation results throughout this article are done by a computer simulation technology (CST) software. The simulated results have been achieved show good performance of S11-parameter and broad side antenna gain on +z-direction. This design has two transmission zeros at 5.4 GHz and 7.7 GHz, and bandwidth (B.W) of about 1.66 GHz so; it is suitable for high speed data communication. This design has good skirt selectivity.