scholarly journals CDBA-Based Universal Biquad Filter and Quadrature Oscillator

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Worapong Tangsrirat ◽  
Tattaya Pukkalanun ◽  
Wanlop Surakampontorn

The voltage-mode universal biquadratic filter and sinusoidal quadrature oscillator based on the use of current differencing buffered amplifiers (CDBAs) as active components have been proposed in this paper. All the proposed configurations employ only two CDBAs and six passive components. The first proposed CDBA-based biquad configuration can realize all the standard types of the biquadratic functions, that is, lowpass, bandpass, highpass, bandstop, and allpass, from the same topology, and can also provide orthogonal tuning of the natural angular frequency(ωo)and the bandwidth (BW) through separate virtually grounded passive components. By slight modification of the first proposed configuration, the new CDBA-based sinusoidal quadrature oscillator is easily obtained. The oscillation condition and the oscillation frequency are independently adjustable by different virtually grounded resistors. The sensitivity analysis of all proposed circuit configurations is shown to be low. PSPICE simulations and experimental results based upon commercially available AD844-type CFAs are included, which confirm the workability of the proposed circuits.

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1493
Author(s):  
San-Fu Wang ◽  
Hua-Pin Chen ◽  
Yitsen Ku ◽  
Chia-Ling Lee

This article presents a versatile voltage-mode (VM) biquad filter with independently electronic tunability. The proposed structure using one dual-output operational transconductance amplifier, three single-output operational transconductance amplifiers (OTAs) and two grounded capacitors was explored to derive a new VM quadrature oscillator with the independent control of the oscillation frequency and the oscillation condition. The proposed versatile VM biquad filter achieves nearly all of the main advantages: (i) simultaneous realizations of band-reject, band-pass, and low-pass from the same architecture, (ii) multiple-input and multiple-output functions, (iii) independent electronic adjustability of quality factor and resonant angular frequency, (iv) no resistor needed, (v) all input terminals with cascade functions, (vi) no additional inverting amplifier for input signals, (vii) using only grounded capacitors, and (viii) easy to implement a VM quadrature oscillator with independent electronically controlled oscillation frequency and oscillation condition. The proposed versatile VM biquad filter employs only four OTAs and two grounded capacitors. The active components of the proposed VM biquad filter are one less than that of recent reports. The proposed circuit also brings versatility and simplicity to the design of VM biquad filters and VM quadrature oscillators. Filters and oscillators with less active and passive components have the advantages of low cost, low power dissipation, low circuit complexity, and low noise. Commercially available integrated circuit LT1228 and discrete components can be used to implement the proposed OTA-based circuits. The simulation and experiment results validated the theoretical analysis.


Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6681
Author(s):  
San-Fu Wang ◽  
Hua-Pin Chen ◽  
Yitsen Ku ◽  
Ming-Xiu Zhong

This research introduces a new multifunction biquad filter based on voltage mode (VM) current-feedback operational amplifier (CFOA) and a fully uncoupled quadrature oscillator (QO) based on the proposed VM multifunction biquad filter. The proposed VM multifunction biquad filter has high impedance to the input voltage signal, and uses three CFOAs as active components, while using four resistors and two grounded capacitors as passive components. The VM CFOA-based multifunction biquad filter realizes band-reject, band-pass, and low-pass transfer functions at high-input impedance node simultaneously, which has the feature of easy cascading in VM operation without the need for additional voltage buffers. Additionally, the filter control factor parameter pole frequency (ωo) and quality factor (Q) of the proposed VM multifunction biquad filter can be independently set by varying different resistors. By slightly modifying the VM multifunction biquad filter topology, a VM fully-uncoupled QO is easily obtained. The difference from the previous VM CFOA-based multifunction biquad filter is that the proposed VM CFOA-based multifunction biquad filter can be independently controlled by the filter control factor parameters, ωo and Q. The proposed VM CFOA-based multifunction biquad filter can be transformed into a VM QO with fully-uncoupled adjustable of the oscillation condition and the oscillation frequency. The oscillation condition and the oscillation frequency can be fully-uncoupled and controlled by varying two sets of completely different resistors. The proposed VM fully-uncoupled QO solves the amplitude instability. The constant amplitude ratio of two quadrature sinusoidal waveforms can be realized when tuning FO. PSpice simulation and experimental results prove the performances of the proposed VM multifunction filter and VM fully-uncoupled QO. Simulation and experimental results confirm the theoretical analysis of the proposed circuits.


2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jiun-Wei Horng

This paper describes a current-mode third-order quadrature oscillator based on current differencing transconductance amplifiers (CDTAs). Outputs of two current-mode sinusoids with90°phase difference are available in the quadrature oscillator circuit. The oscillation condition and oscillation frequency are orthogonal controllable. The proposed circuit employs only grounded capacitors and is ideal for integration. Simulation results are included to confirm the theoretical analysis.


2013 ◽  
Vol 22 (01) ◽  
pp. 1250077 ◽  
Author(s):  
CHEN-NONG LEE

This paper presents a versatile universal current-mode and transresistance-mode biquadratic filter using only two multiple outputs second-generation current conveyors (MOCCIIs), two grounded capacitors, and three grounded resistors. The proposed configuration can realize all five standard filtering functions from one current-output terminal and one voltage-output terminal, and also provide all these filtering functions from different current-output and voltage-output terminals without changing the filter topology. Moreover, the proposed biquad filter still achieves many advantages like the employment of all grounded passive components, and the minimum number of active component counts, in addition to having no need of inverting-type input signals or double-type input signals for the use of special input signals, high output impedance and low sensitivity performance. H-Spice simulation results confirm the theory.


2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Montree Kumngern ◽  
Kobchai Dejhan

A new voltage-mode quadrature oscillator using two differential difference current conveyors (DDCCs), two grounded capacitors, and three grounded resistors is presented. The proposed oscillator provides the following advantages: the oscillation condition and oscillation frequency are orthogonally controlled; the oscillation frequency is controlled through a single grounded resistor; the use of only grounded capacitors and resistors makes the proposed circuit ideal for IC implementation; low passive and active sensitivities. Simulation results verifying the theoretical analysis are also included.


Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2349 ◽  
Author(s):  
San-Fu Wang ◽  
Hua-Pin Chen ◽  
Yitsen Ku ◽  
Yi-Chun Lin

This paper presents a versatile tunable voltage-mode biquadratic filter with five inputs and three outputs. The proposed filter enjoys five single-ended output operational transconductance amplifiers (OTAs) and two grounded capacitors. The filter can be easily transformed into a quadrature oscillator. The filter with grounded capacitors is resistorless and electronically tunable. Either a voltage-mode five-input single-output biquadratic filter or a voltage-mode single-input three-output biquadratic filter can be operated by appropriate selecting input and output terminals. In the operation of five-input single-output biquadratic filter, the non-inverting lowpass, non-inverting bandpass, inverting bandpass, inverting highpass, non-inverting bandreject, inverting bandreject, and non-inverting allpass filtering responses can be realized by appropriately applying the input voltage signals. In the operation of single-input three-output biquadratic filter, the non-inverting/inverting lowpass, bandpass and bandreject filtering responses can be realized simultaneously. The circuit provides independent adjustment of the resonance angular frequency and quality factor, high-input impedance, and no inverting-type input voltage signals are imposed. The application in quadrature oscillator exhibits independent electronic tuning characteristic of the oscillation condition and the oscillation frequency. The theoretical analysis has been verified through OrCAD PSpice and furthermore by experimental measurements.


2019 ◽  
Vol 29 (04) ◽  
pp. 2050052
Author(s):  
San-Fu Wang ◽  
Hua-Pin Chen

This paper presents two new voltage-mode sinusoidal oscillators based on voltage differencing inverting buffered amplifier (VDIBA). The first proposed circuit exhibits independent and electronic control of oscillation condition by using the bias current of the VDIBA. The proposed configuration contains only single VDIBA, two grounded capacitors and two resistors, which are the least number of active components and the minimum number of passive components necessary for realizing voltage-mode oscillator topology. The second proposed circuit exhibits independent and electronic control on the condition of oscillation without affecting the oscillation frequency by adjusting the separate bias currents of the VDIBAs. The proposed configuration contains two VDIBAs, two grounded capacitors and one resistor, which can provide four quadrature voltage outputs simultaneously. Both proposed circuits enjoy only two grounded capacitors, which are suitable for monolithic integration. HSpice simulations and experimental results are included to confirm the theoretical analysis.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hua-Pin Chen

The electronically tunable quadrature oscillator using a single multiple-output current controlled current differencing transconductance amplifier (MO-CCCDTA) and grounded passive components is presented. The proposed configuration uses a single MO-CCCDTA, two grounded capacitors and one grounded resistor. Two high-output impedance quadrature current signals and two quadrature voltage signals with 90° phase difference. The oscillation condition and oscillation frequency of the proposed quadrature oscillator are independently controllable. The use of only grounded passive components makes the proposed circuit ideal for integrated circuit implementation.


2019 ◽  
Vol 9 (11) ◽  
pp. 2304 ◽  
Author(s):  
San-Fu Wang ◽  
Hua-Pin Chen ◽  
Yitsen Ku ◽  
Po-Yu Chen

This paper proposes a new high-input impedance current feedback operational amplifier (CFOA)- based voltage-mode multifunction biquadratic filter and a voltage-mode quadrature oscillator using the proposed high-input impedance CFOA-based biquadratic filter. The proposed high-input impedance CFOA-based voltage-mode multifunction biquadratic filter uses three CFOAs, three resistors, and two grounded capacitors with two inputs and three outputs. The filter can simultaneously realize non-inverting low-pass, non-inverting band-pass, and non-inverting band-reject filtering functions at the high-input impedance terminal while the inverting band-pass and non-inverting high-pass filtering functions can also be obtained by applying another high-input impedance terminal. The filter offers orthogonal control of resonance angular frequency and quality factor. The proposed high-input impedance CFOA-based voltage-mode multifunction biquadratic filter can be used to implement a voltage-mode quadrature oscillator with an independently controlled the frequency of oscillator and the condition of oscillation. The OrCAD PSpice simulation and experimental results of the commercially available integrated circuit, AD844AN, are used to confirm the characteristics of the proposed filter and oscillator.


2013 ◽  
Vol 712-715 ◽  
pp. 1881-1885
Author(s):  
Lei Zhang ◽  
Zhong Ming Pan

A class of single-resistance-controlled (SRC) quadrature sinusoidal oscillator using CFOAs for GMI magnetic sensors is presented in this paper. By means of state variable, the proposed circuits are designed and analyzed which has the advantages such as noninteractive control of the oscillation condition (CO) and the oscillation frequency (FO), good sensitivity performance and minimum components including grounded capacitors. Moreover, the workability of the proposed circuit has been verified by PSPICE simulations.


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