Higher order differentiator block for synthesis of controllable frequency dependent elements

This paper presents structure of generally nth-order differentiator transfer block serving for purpose of integer order or fractional order immittance (impedance) synthesis. Presented structure of the differentiator is based on electronically controllable current conveyors (ECCIIs), current conveyor of second generation (CCII) and electronically controllable gain amplifier (VGA). This structure was applied as example of 3rd order differentiator and frequency dependent negative resistors (FDNRs) of integer (as well as fractional) order. Proposed applications offer electronic controllability of time constant, magnitude value and reconfigurability of impedance character (between positive and negative). PSpice simulations were performed in order to verify presented concepts.