Active‐C Realization of Multifunction Biquadratic Filter and Third‐Order Oscillator

Abstract

The paper introduces a new circuit of voltage-mode multifunction biquadratic filter employing one fully differential second-generation current conveyor, three active resistors, and two capacitors. The circuit uses metal oxide semiconductor-based active resistors instead of passive resistors to make the circuit more suitable for monolithic integration as well as to provide additional feature of electronically controllable pole frequency. Low-pass, high-pass, band-pass, and band-reject filtering functions are simultaneously realizable without need of any component matching constraints from the proposed multifunction biquadratic filter. Additionally, the nonideal aspects of multifunction biquadratic filter circuit are studied. Furthermore, a third-order dual-mode quadrature oscillator is also derived from the low-pass function of the proposed multifunction filter to check its applicability. The proposed oscillator structure makes the output current readily available from high-impedance terminals. The performance of both multifunction biquadratic filter circuit and oscillator circuit is examined with the help of HSPICE simulations.

Systematic realization of low‐frequency third‐order sinusoidal oscillators

“…• A cascade connection of second-order low-pass filter and an inverting integrator in a loop with unity feedback. [10][11][12][13][14][15][16][17][18][19][20][21][22][23]50 • A cascade connection of second-order high-pass filter with noninverting differentiator in a loop. 16,17,50 • A combination of an inverting lossy integrator with two lossless noninverting integrators in a loop.…”

MOS-C Based Electronically Tuneable Current/Voltage-Mode Third Order Quadrature Oscillator and Biquadratic Filter Realization

“…1. One or more floating components are used in [28], [29], [31]- [35], [37], [38], [40], [41], and [44]; 2. Quadrature outputs are not available in [29] and [38];…”

“…Both current-mode and voltage-mode outputs are not available in the same topology in [28], [29], [32], [34]- [38], [40], and [44]; 7. Frequency tuning can be done using symmetrical voltage in [40], which is not practical as much as using a single control voltage like in the proposed circuit. The content of the remaining chapters of this paper is composed as follows.…”