Design of Electronically Adjustable Fractional Order Immittances Using Single Active Device

This paper brings new approach for the design and construction of electronically adjustable immittance functions using single compact commercially available active device (VCAS22). Some of parameters of designed circuits can be controlled electronically thanks to type of used active device. Presented design uses RC approximants of fractionalorder element (order 1/4) in three application examples (fractional-order adjustable capacitance, inductance and frequency dependent negative resistor). PSpice simulations confirm expected behavior and tunability described by theoretical expressions (in wide band up to 10 MHz).