scholarly journals Single Commercially Available IC-Based Electronically Controllable Voltage-Mode First-Order Multifunction Filter with Complete Standard Functions and Low Output Impedance

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7376
Author(s):  
Winai Jaikla ◽  
Unchittha Buakhong ◽  
Surapong Siripongdee ◽  
Fabian Khateb ◽  
Roman Sotner ◽  
...  

This paper presents the design of a voltage-mode three-input single-output multifunction first-order filter employing commercially available LT1228 IC for easy verification of the proposed circuit by laboratory measurements. The proposed filter is very simple, consisting of a single LT1228 as an active device with two resistors and one capacitor. The output voltage node is low impedance, resulting in an easy cascade-ability with other voltage-mode configurations. The proposed filter provides four filter responses: low-pass filter (LP), high-pass filter (HP), inverting all-pass filter (AP−), and non-inverting all-pass filter (AP+) in the same circuit configuration. The selection of output filter responses can be conducted without additional inverting or double gains, which is easy to be controlled by the digital method. The control of pole frequency and phase response can be conducted electronically through the bias current (IB). The matching condition during tuning the phase response with constant voltage gain is not required. Moreover, the pass-band voltage gain of the LP and HP functions can be controlled by adjusting the value of resistors without affecting the pole frequency and phase response. Additionally, the phase responses of the AP filters can be selected as both lagging or leading phase responses. The parasitic effects on the filtering performances were also analyzed and studied. The performances of the proposed filter were simulated and experimented with a ±5 V voltage supply. For the AP+ experimental result, the leading phase response for 1 kHz to 1 MHz frequency changed from 180 to 0 degrees. For the AP− experimental result, the lagging phase response for 1 kHz to 1 MHz frequency changed from 0 to −180 degrees. The design of the quadrature oscillator based on the proposed first-order filter is also included as an application example.

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
K. L. Pushkar ◽  
D. R. Bhaskar ◽  
Dinesh Prasad

A new multiple-input single-output-(MISO-)-type multifunction voltage-mode universal biquadratic filter employing single voltage differencing differential input buffered amplifier (VD-DIBA), two capacitors, and one resistor are proposed. The proposed structure can realize second-order low pass, high pass, band pass, band stop, and all pass filter responses without altering the circuit topology. The proposed new filter configuration also provides the following advantageous features, not available simultaneously in any of the single active device /element-based universal biquad in realizing all the five filter functions known earlier so far: (i) no requirement of any passive component(s) matching condition or inversion of input signal(s), (ii) independent electronic control of angular frequency () and bandwidth (BW), and (iii) low active and passive sensitivities. SPICE simulation results have been included using 0.35 µm TSMC technology to confirm the validity of the proposed new universal biquadratic filter configuration.


Circuit World ◽  
2020 ◽  
Vol 46 (2) ◽  
pp. 117-124
Author(s):  
Huijun Gan ◽  
Dongsheng Yu ◽  
Dongkun Li ◽  
He Cheng

Purpose The purpose of this paper is to construct a flux-controlled memcapacitor (MC) emulator without grounded restriction with the binary operation ability. The active first-order low-pass filter (LPF) and high-pass filter (HPF) circuits are constructed by replacing the capacitor with MC. Design/methodology/approach The output saturation of the active device is innovatively adopted to realize the binary operation of MC with two memcapacitance values. By applying the direct current control voltage together with the input signal, the memcapacitance can be controlled, and hence, cut-off frequency of the filters can be adjusted without changing the circuit structure. Findings Experiments and simulation results show that the new filter has good frequency selectivity. Both LPF and HPF can change the cut-off frequency by changing the positive and negative control voltage. The experimental and simulation results are in good agreement with the theoretical analysis, which proves the feasibility and validity of the emulator and the filters. Originality/value These MC emulators are simple and easy to physically fabricate, which have been increasingly used for experiment. It also provide an effective reference for device miniaturization and low power consumption.


2017 ◽  
Vol 26 (10) ◽  
pp. 1750157 ◽  
Author(s):  
Jan Jerabek ◽  
Roman Sotner ◽  
Jan Dvorak ◽  
Josef Polak ◽  
David Kubanek ◽  
...  

This paper presents design of electronically reconfigurable fractional-order filter that is able to be configured to operate as fractional-order low-pass filter (FLPF) or fractional-order high-pass filter (FHPF). Its slope of attenuation between pass band and stop band, i.e., order of the filter, is electronically adjustable in the range between 1 and 2. Also, pole frequency can be electronically controlled independently with respect to other tuned parameters. Moreover, particular type of approximation can be also controlled electronically. This feature set is available both for FLPF and FHPF-type of response. Presented structure of the filter is based on well-known follow-the-leader feedback (FLF) topology adjusted in our case for utilization with just simple active elements operational transconductance amplifiers (OTAs) and adjustable current amplifiers (ACAs), both providing possibility to control its key parameter electronically. This paper explains how reconfigurable third-order FLF topology is used in order to approximate both FLPF and FHPF in concerned frequency band of interest. Design is supported by PSpice simulations for three particular values of order of the filter (1.25, 1.5, 1.75), for several values of pole frequency and for two particular types of approximation forming the shape of both the magnitude and phase response. Moreover, theoretical presumptions are successfully confirmed by laboratory measurements with prepared prototype based on behavioral modeling.


2013 ◽  
Vol 273 ◽  
pp. 371-374
Author(s):  
Bao Ping Li ◽  
Yan Liang Zhang

Due to the frequency response periodicity of distributed transmission line, microstrip band-pass filter usually produces parasitic pass-band and outputs harmonics away from the center frequency of main pass-band. Based on the study of rectangular ring defected ground structure, a 5-order microstrip LPF(low-pass filter) was designed using the single-pole band-stop and slow-wave characteristics of the rectangular ring DGS(Defected Ground Structure) and SISS(Step-Impedance Shunt Stub) structure. Compared with traditional LPF, this LPF presents the advantages of compact size, low insertion loss, broad stop-band and high steep. It also validates the requirements of miniaturization and high performance for filters.


2013 ◽  
Vol 562-565 ◽  
pp. 1132-1136
Author(s):  
Xiao Wei Liu ◽  
Jian Yang ◽  
Song Chen ◽  
Liang Liu ◽  
Rui Zhang ◽  
...  

In this paper, we design a high-order switched capacitor filter for rapid change parameter converter. This design uses a structure which consists of three biquads filter sub-units. The design is a 6th-order SC elliptic low-pass filter, and the sample frequency is 250 kHz. By the MATLAB Simulink simulation, the system can meet the design requirements in the time domain. In this paper, the 6th-order switched capacitor elliptic low-pass filter was implemented under 0.5 um CMOS process and simulated in Cadence. The final simulation results show that the pass-band cutoff frequency is 10 kHz, and the maximum pass-band ripple is about 0.106 dB. The stop-band cutoff frequency is 20 kHz, and the minimum stop-band attenuation is 74.78 dB.


2016 ◽  
Vol 26 (03) ◽  
pp. 1750048 ◽  
Author(s):  
Vida Orduee Niar ◽  
Gholamreza Zare Fatin

In this paper, a [Formula: see text]-[Formula: see text] low-pass and low power filter with tunable in-band attenuation for WiMAX/LTE receiver is presented. The fourth-order filter consists of two cascaded biquad stages. The source-follower (SF) stage is used as a key building block in these biquads. In this paper, we have presented a circuit technique to reduce the nonlinearity of the SF stage resulting from unmatched signal swings at the gate and source terminals of the input transistor. The proposed SF stage, is used for design of a linear biquad which is then utilized in a fourth-order Butterworth low-pass filter. The simulation results of the filter for bandwidth of 10 MHz show that the IIP3 of the filter is equal to 8.22[Formula: see text]dBm, in-band noise density is 100[Formula: see text]nV/[Formula: see text]Hz and power consumption is 5.9[Formula: see text]mW. The supply voltage of the filter is equal to 1[Formula: see text]V.


2021 ◽  
Vol 11 (21) ◽  
pp. 10369
Author(s):  
Štefan Chamraz ◽  
Mikuláš Huba ◽  
Katarína Žáková

This paper contributes toward research on the control of the magnetic levitation plant, representing a typical nonlinear unstable system that can be controlled by various methods. This paper shows two various approaches to the solution of the controller design based on different closed loop requirements. Starting from a known unstable linear plant model—the first method is based on the two-step procedure. In the first step, the transfer function of the controlled system is modified to get a stable non-oscillatory system. In the next step, the required first-order dynamic is defined and a model-based PI controller is proposed. The closed loop time constant of this first-order model-based approach can then be used as a tuning parameter. The second set of methods is based on a simplified ultra-local linear approximation of the plant dynamics by the double-integrator plus dead-time (DIPDT) model. Similar to the first method, one possible solution is to stabilize the system by a PD controller combined with a low-pass filter. To eliminate the offset, the stabilized system is supplemented by a simple static feedforward, or by a controller proposed by means of an internal model control (IMC). Another possible approach is to apply for the DIPDT model directly a stabilizing PID controller. The considered solutions are compared to the magnetic levitation system, controlled via the MATLAB/Simulink environment. It is shown that, all three controllers, with integral action, yield much slower dynamics than the stabilizing PD control, which gives one motivation to look for alternative ways of steady-state error compensation, guaranteeing faster setpoint step responses.


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