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In this article, a general all-pole current transfer function synthesis procedure using current backward transconductance amplifiers (CBTAs) is proposed. The proposed configuration uses n current backward transconductance amplifiers and n grounded capacitors as the only type of passive elements. The circuit is eligible to realize any all-pole transfer characteristics with a given strictly Hurwitz (stable) denominator polynomial. Further, it is straightforward to find the values of the passive elements from the coefficients of this polynomial by using the Routh–Hurwitz algorithm as in the realization of a two-element kind passive network synthesis. In this sense and as far as the author's knowledge, it is the only active structure that can be synthesized like a passive two-element kind Cauer circuit. The simulations that are performed using PSPICE exhibit satisfactory results coherent with the theory. Copyright © 2011 John Wiley & Sons, Ltd.

WOS: 000300771700002, A novel circuit for the realization of the mutually coupled circuit using three current-controlled current backward transconductance amplifiers (CC-CBTAs) as active components is proposed. The active mutually coupled circuit structures are also called the synthetic transformers. The circuit is derived by using three floating simulated inductors that are connected as the T-type transformer model. The circuit has the following attractive advantages: (i) The values of a primary self-inductance, a secondary self-inductance and a mutual inductance can be independently tuned by the transconductance gain of the CC-CBTAs; (ii) The circuit uses three grounded capacitors that are suitable from the point of integrated circuit implementation; (iii) It uses only three active components; (iv) It has a good sensitivity performance with respect to the tracking errors; (v) Both positive and negative couplings are achieved and the coupling coefficient is not limited by 1 in magnitude; (vi) Symmetrical coupling is achieved without necessitating any matching condition; (vii) The proposed circuit has a floating structure.

A general synthesis procedure is given for a versatile signal flow graph realization of a general current transfer function by using multi-output second generation current controlled current conveyors (MO-CCCIIs). The proposed configuration uses n + 1 multi-output second generation current conveyors (MO-CCIIs), n capacitors and at most 2 ( n + 1 ) resistors. This number of resistors can be reduced to n for special cases. Using MO-CCCIIs instead of MO-CCIIs, the resistors can be removed completely for the n th-order universal structure. The general transfer function having any numerator dynamics can be derived from the universal structure by using a single MO-CCCII and at most n + 1 resistors. It is very easy to find the values of the passive elements from the coefficients of the transfer function to be realized. The validity of the proposed synthesis is verified through PSpice simulations.

A general synthesis procedure is given for a versatile signal flow graph realization of a general transfer function by using current differencing buffered amplifier (CDBA). The proposed configuration uses n + 1 CDBAs, n capacitors and at most 2 n + 4 resistors. This number of resistors can be reduced to n + 1 for special cases. The circuit is eligible to obtain a variety of transfer characteristics with the same common denominator polynomial, and it is easily converted to different modes of operations. It is straightforward to find the values of the passive elements from the coefficients of the transfer function to be realized. Simulations results are obtained by using commercially available active component AD844 and CMOS technology as well. All of these make the proposed circuit attractive.

In this work, a novel voltage-mode (VM) single-input four-output universal filter topology is presented. The proposed structure uses two resistors, two capacitors and only one voltage differencing current conveyor (VDCC) and generates all biquadratic filtering functions namely: low-pass (LP), band-pass (BP), high-pass (HP) and band-reject (BR). The quality factor and natural frequency of the filter can be adjusted electronically without changing the values of the passive components. Moreover, the circuit does not require any condition of component matching and has a good sensitivity performance with respect to tracking errors of passive components and the active parameter. PSpice simulation results confirm the results of the theoretical analysis.

A proportional integral derivative (PID) controller employing only a single commercially available active component, two resistors and two capacitors is presented. The PID controller circuit has low impedance voltage output which can be easily cascaded with other voltage-mode (VM) structures. The effects caused by the non-ideality of the current feedback operational amplifier (CFOA) are analyzed. The performance of the proposed circuit is demonstrated by using PSPICE simulations.

WOS: 000305249000013, In this paper, a general electronically tunable resistorless biquad, which realizes current ratio transfer function using current backward transconductance amplifiers is proposed. The biquad contains only two active components and two grounded capacitors, which make it convenient for production by the integrated circuit technology. The proposed biquad realizes all of the basic second order filter characteristics: low pass, high pass, band pass, band reject, and finally all pass. It is convenient for cascading with other similar biquads as well as with any two-port circuit with low impedance input to achieve higher order filter characteristics. The simulations that are performed using PSPICE simulator exhibit satisfactory results coherent with the theory.

WOS: 000262504400004, A new floating immittance function simulator circuit is proposed using two different active elements, a dual-output second generation current conveyor (DO-CCII) and an operational transconductance amplifier (OTA). The presented circuit can realize a positive and negative floating inductor, capacitor and resistor depending on the passive component selection. Since the passive elements are all grounded, this circuit is suitable for fully integrated circuit design. The circuit does not require any component matching conditions, and it has a good sensitivity performance with respect to tracking errors. Moreover, the proposed positive and negative inductance, capacitor and resistor simulator can be tuned electronically by changing the biasing current of the OTA or can be controlled through the grounded resistor or capacitor. The proposed floating inductor simulator circuit is demonstrated by using a SPICE simulation for 0.35 mu m TSMC CMOS technology. The proposed circuit consumes an average power of 1 mW using +/- 1.5 V supply voltages.

European Conference on Circuit Theory Design -- AUG 23-27, 2009 -- Antalya, TURKEY, WOS: 000276473700173, A new second-order multi-mode multifunction filter configuration is introduced. This configuration uses a single current differencing buffered amplifier (CDBA) and, depending on topology, a total of four/five passive elements (two/three capacitors and two/three resistors). Current-mode (CM), voltage-mode (VM), transimpedance-mode (TIM) and transadmittance-mode (TAM) topologies are presented for realizing BP, LP and HP filter responses. The validity of the proposed filters is verified through PSpice simulations and experiments.

WOS: 000264490800009, A novel resistorless oscillator is presented. The proposed structure enjoys electronic tunability property with minimum number of active and passive components. This oscillator uses a current-mode (CM) active device and has properties of current mode circuits. The validity of the proposed circuit is verified by experimental results.

Three new electronically tunable filter configurations which employ only one current controlled differencing buffered amplifier (CDBA) are proposed. The proposed filters operate in voltage-mode (VM) and use three passive elements. Each proposed filter can realize one of the band-pass, low-pass or high-pass responses. The parameters /spl omega//sub 0/ and /spl omega//sub 0//Q enjoy independent electronic tunability. Effect of the non-idealities and the sensitivity analysis of the proposed filter are also examined. The validities of the proposed filters are verified through PSPICE simulations.