A voltage-mode universal biquadratic filter using a differential voltage current conveyor (DVCC), two capacitors, and two resistors is presented. The proposed circuit has four input terminals and three output terminals and can realize all the standard filter functions, which are lowpass, bandpass, highpass, notch, and allpass filters, without changing the circuit topology. Three simultaneous output filter responses can be obtained from some derived filter types. The proposed circuit employs only one DVCC that simplifies the configuration.

Recently, there is a growing interest in designing current-conveyor- (CC-) or current-feedback-amplifier- (CFA-) based active filters. This is attributed to their high signal bandwidths, greater linearity, and larger dynamic range than OPAMP-based ones [

Active filters are so widely used in electronic systems, such as telecommunications, radar, consumer electronics, instrumentation systems, and military ordnance, [

In this paper, a voltage-mode universal biquadratic filter circuit that has four input terminals and three output terminals is presented. It can realize all the standard filter functions, which is, lowpass, bandpass, highpass, notch, and allpass filters, without changing the circuit topology. With respect to the previous single active element universal biquad in Horng et al. [

The port relations of a CCII can be characterized by

The proposed voltage-mode universal biquad.

From (

If

If

If

If

If

If

If

If

If

If

If

If

If

Thus, the circuit is capable of realizing all voltage-mode filter functions. Note that three standard filter responses can be obtained simultaneously from the circuit types (e) and (i).

Taking into consideration the DVCC nonidealities, the port relations of DVCC can be expressed as

HSPICE simulations were carried out to demonstrate the feasibility of the proposed circuits using 0.18

The CMOS DVCC implementation.

Figures

Simulated frequency responses of Figure

Figures

Simulated frequency responses of Figure

In this paper, a new voltage-mode universal biquadratic filter has been presented. The new voltage-mode circuit with four input terminals and three output terminals employs two capacitors, two resistors, and one DVCC. The new circuit has the features of using only four passive components and does not need one more active component in the realizations of notch and allpass filters and the availability of three simultaneous output filter responses from some derived filter types (types (e) and (i)).

The National Science Council, China, supported this work under Grant no. NSC 101-2221-E-033-070.