Realization of nth-order series impedance function using only (n-1) current-feedback amplifiers

Abstract

A new con® guration for realizing a higher-order series impedance function using current-feedback ampli® ers (CFAs) is presented. The nth-order series impedance function employs only (n 1) CFAs and (2n 1) passive elements. The higherorder series impedance function can be applied to realize various higher-order highpass and lowpass ® lters. The passive element values can be easily decided from the coe cients of the ® lter transfer functions. The use of CFAs simpli® es the circuit implementation and makes the proposed circuit attractive for application. Experiments and simulation results are given to con® rm the theoretical analysis.

General high-order grounded and floating immittance structures using current conveyors

“…However, the realizations of high-order immittance functions have received less attention. Several high-order immittance functions were presented in [5][6][7][8][9]. However, only series and parallel immittance functions can be obtained in these papers.…”

Higher-order immittance functions using current conveyors

“…The proposed circuits using only grounded passive components. With respect to the previous higherorder immittances circuit configurations in [1][2], the proposed circuits using only grounded passive components. The use of only grounded capacitors and resistors is beneficial from the point of view of integrated circuit fabrications [4][5][6].…”

“…However, the passive components they employed cannot be all grounded. Weng et al proposed a configuration for realizing higher-order series impedance function using currentfeedback amplifiers (CFAs) [2]. However, this configuration employs floating resistors and capacitors.…”

Electronically Tunable Frequency Filters Based on Transformation Cells

“…A more suitable solution is to deliberately design parallel or series structures of synthetic elements with continuously increasing order of immittance. The realization of a series combination of grounded immittances with the CFA (Current-Feedback Amplifiers) active elements is presented in [10]. A parallel combination of grounded immittances is then discussed in [11], where the FTFN (Four-Terminal Flooding Nullor) active element is used.…”