Design of integer/fractional-order filter with electronically reconfigurable transfer response

摘要

This paper presents a new realization of filtering topology having continuously and electronically reconfigurable transfer responses between inverting direct transfer (iDT), inverting high-pass responses (iHP), and all-pass response (AP). Proposed topology employs two active elements, single resistor, and single grounded capacitor. The behavior of the circuit is tested in PSpice utilizing simple commercially available elements from Analog Devices (variable gain amplifier and differential voltage buffer). Analyzes focus on standard implementation with integer-order capacitor as well as on employment of so-called constant phase element (fractional-order capacitor) and reveals interesting differences between transfer responses.