Current conveyors in current-mode circuits approximating fractional-order low-pass filter

Using current conveyors, we present six different current-mode circuits approximating fractional-order low-pass transfer function. Proposed circuits always use four active elements, three capacitors and seven or five resistors, whereas all are grounded. We show that the usage of only eight passive elements is sufficient to approximate a (1 + α)-order system (0 < α < 1) and can even provide better performance. The performance of the circuits is analysed evaluating the relative errors in magnitude and phase.