Electronically tunable current-mode active-only biquadratic filter

Abstract

This paper presents a realization of current-mode active-only ® lter. The proposed ® lter is constructed employing operational ampli® ers and operational transconductance ampli® ers (OTAs). The circuit can realize biquadratic transfer function, and the circuit characteristics can be electronically tuned through adjusting the transconductance gains of the OTAs. An example is given together with simulated result by PSPICE. The circuit con® guration is very suitable for implementation in both bipolar or CMOS technologies.

New active-only grounded inductance simulator employing current-mode approach suitable for wide band operation

“…where I A is the biasing current, B is the current multiplication factor and k 0 n W 1 L 1 is the process transconductance parameter of the input transistors (Tsukutani et al 2000). The inductance value is obtained as…”

“…In all reported papers on active-only filters and inductance simulators (Ishida et al 1986;Khan et al 1992;Higashimura 1993;Tsukutani et al 1996;Abuelma'atti and Alzaher 1997;Singh and Senani 1998;Ohtsuki et al 1999;Tsukutani et al 2000;Cicekoglu et al 2001;Ohtsuki et al 2001;Tsukutani et al 2001a,b;Tsukutani et al 2002;Minaei et al 2003a,b), a VOA is employed just for its integrator behaviour; they are operated in voltage or current mode regardless. These circuits have some disadvantages caused from using a VOA which operates in a limited frequency range determined by the integrator portion of its characteristic.…”

“…The open-loop gain characteristics of a VOA exhibit a voltage-mode integrator attribute, hence permiting the design of 'active-only' topologies. Recently, a lot of circuit designs including inductance simulators, filters and oscillators without external passive elements have been reported in which VOAs and operational transconductance amplifiers (OTAs) are generally employed as active elements (Ishida et al 1986;Khan et al 1992;Higashimura 1993;Tsukutani, Ishida, Tsuki and Fukui 1996;Abuelma'atti and Alzaher 1997;Singh and Senani 1998;Ohtsuki et al 1999;Tsukutani, Higashimura, Sumi and Fukui 2000;Cicekoglu, Toker and Kuntman 2001;Ohtsuki et al 2001;Tsukutani, Higashimura, Takahashi, Sumi and Fukui 2001a,b;Tsukutani, Kinugasa, Higashimura, Sumi and Fukui 2002;Minaei, Cicekoglu, Kuntman, Dundar and Cerid 2003a;Minaei, Topcu and Cicekoglu 2003b).…”

An Optimized Design Methodology &Synthesis for Stability of 3rd-Pole Current-Mode Active-R Filter

“…Analog filters are important building blocks and widely used for continuous-time signal processing [1]. In recent years, the current mode analogue signal processing circuit techniques have received wide attention due to the high accuracy, the wide signal bandwidth and the simplicity of implementing signal operations [2,3]. In filter circuit designs, current-mode filters are becoming popular since they have many advantages compared with their voltage-mode counter parts, the current-mode filters have large dynamic range, higher bandwidth, greater linearity, simple circuitry, and low power consumption etc.…”

Realization of Lowpass and Bandpass Leapfrog Filters Using OAs and CCCIIs

“…Due to the fact that active filter designs utilizing the finite and complex gain nature of an internally compensated type operational amplifier are suitable for integrated circuit(IC) fabrication and high frequency operation. Several implementations in continuous-time filters using only active components are recently available in the literature [3][4][5][6] . They have been demonstrated that the realizations of the resistor-less and capacitor-less active-only circuit would be attractive for simplicity, integratability, programmability and wide frequency range of operation.…”