Versatile composite amplifier configuration

IET Circuits, Devices & Systems

Mathur

Venkateswaran

2017

New realisation scheme of linear voltage-controlled quadrature oscillator (QO) is proposed. The active building block is electronically tunable (ET) differential voltage current conveyor transconductance (g m) amplifier configured with current feedback amplifier and multiplication mode current conveyor devices. The designs are essentially tuned-inductor-capacitor oscillator, wherein the electronically variable lossless grounded inductor (L) had been simulated at suitable nodes of the active building block. Subsequently, with slight modification of the block, an ET floating-lossless immittance function generation is presented. Effects of device port mismatch error and parasitic capacitances are analysed. Albeit sensitivity relative to port mismatch error is negligible, the parasitic components tend to limit the higher-usable frequency range; appropriate design equations are derived for a true bilinear admittance function realisation and their applications to filter and sinusoid oscillator design are included. Experimental results on the QO with linear f o-tuning law are satisfactorily verified up to 8.7 MHz at low total harmonic distortion.

Section: Resultsmentioning

confidence: 99%

“…A composite structure of active elements had been seen to yield better realisability which a single constituent element may not be able to provide [35]. Recent literature also suggests various exclusive parametric attributes of the CFA for such functional circuit design [32].…”

Section: Resultsmentioning

confidence: 99%

Quadrature voltage control oscillator with a linear tuning law

IET Circuits, Devices & Systems

Mathur

Venkateswaran

2017

“…Here we present a simple electronically tunable dual-input integrator (ETDI) topology based on a composite current feedback amplifier- (CFA-) multiplication mode current conveyor (MMCC) building block. It has been pointed out in the recent literature [ 20 , 21 ] that utilization of two different kinds of active elements to form a composite building block yields superior functional result in analog signal processing applications.…”

Section: Introductionmentioning

confidence: 99%

Electronically Tunable Differential Integrator: Linear Voltage Controlled Quadrature Oscillator

International Scholarly Research Notices

Pattanayak²,

Venkateswaran

et al. 2015

A new electronically tunable differential integrator (ETDI) and its extension to voltage controlled quadrature oscillator (VCQO) design with linear tuning law are proposed; the active building block is a composite current feedback amplifier with recent multiplication mode current conveyor (MMCC) element. Recently utilization of two different kinds of active devices to form a composite building block is being considered since it yields a superior functional element suitable for improved quality circuit design. The integrator time constant (τ) and the oscillation frequency (ω o) are tunable by the control voltage (V) of the MMCC block. Analysis indicates negligible phase error (θ e) for the integrator and low active ω o-sensitivity relative to the device parasitic capacitances. Satisfactory experimental verifications on electronic tunability of some wave shaping applications by the integrator and a double-integrator feedback loop (DIFL) based sinusoid oscillator with linear f o variation range of 60 KHz~1.8 MHz at low THD of 2.1% are verified by both simulation and hardware tests.

“…Present work is also of composite MMCC-CFA building block category wherein we obtained better performance with respect to frequencyrange at low THD. Literature suggests that a composite structure of active devices may yield better flexibility and design versatility that a single constituent unit may not provide [15].…”

Section: Introductionmentioning

confidence: 99%

Electronically tunable allpass filter: linear VCO design

IEICE Electron. Express

Mathur

Pattanayak³

2016

A new electronically tunable allpass filter (ETAF) realization using the composite Current Feedback Amplifier (CFA) and Multiplication Mode Current Conveyor (MMCC) building blocks is proposed. First order non-minimum phase function with electronically variable output phase is derived. Extension of the filter to a linear quadrature-VCO design is then implemented. Simulation test responses of all these functions are satisfactorily verified.