Realizations of Voltage Transfer Functions Using DVCCs

Tejmal S Rathore

doi:10.4236/cs.2018.910015

Abstract

Maheshwari has proposed three differential-voltage current-conveyor configurations for realizing first order all-pass filters only. This paper has exploited these configurations for realizing more complex transfer function T(s) which yield poles and zeros of 1 - T(s) in one of the four admissible patterns. Bilinear and biquadratic functions are dealt in detail. It is shown that only bilinear functions can be realized with all the four passive elements grounded. First order all-pass function is a special case which needs only three elements (2R, 1C) or (1R, 2C). A biquadratic function requires (2R, 2C) elements and has all the capacitor grounded. Design of second order all-pass function is given.

Highlights

It is shown that only bilinear functions can be realized with all the four passive elements grounded
Former case, it is shown that only first order functions can have all passive components grounded, and that there are only two possible cases with minimum number of passive elements (1C 2R and 2C 1R) logically, rather than intuitionally in [2]
Impedances Z1 and Z2 can be identified as RC driving point functions (DPIs) from (3), if the poles and zeros of Z1Y2, arranged in pairs starting from the rightmost pair, each pair consists of a pole and a zero in either order [3]

Summary

Introduction

1 and its characteristics are summarized by the following port relationships [1]. Maheshwari [2] has proposed three configurations, shown in Figure 2, using DVCC for realizing only first order voltage-mode all-pass filter. Maheshwari [2] has proposed three configurations, shown, using DVCC for realizing only first order voltage-mode all-pass filter. The filter has the advantages of high input resistance and minimum number of RC elements and all of them grounded. We consider realizations of bilinear and biquadratic functions in detail. Former case, it is shown that only first order functions can have all passive components grounded, and that there are only two possible cases with minimum number of passive elements (1C 2R and 2C 1R) logically, rather than intuitionally in [2]. In case of biquadratic function only 4 passive elements (2C, 2R) are required with both the capacitors grounded. Desing of a second order all-pass function is given

Realization of a General Voltage Transfer Function

Realization of Bilinear Voltage Transfer Functions

Realization of Biquadratic Transfer Functions

Conclusion