All-pass filters realised using the current-controlled CCII with intrinsic negative resistance

Abstract

Novel first-order all-pass filter configurations are introduced in this article for the first time using CCIIs with negative intrinsic resistance. The first one offers the benefit of the high-impedance input with a simultaneous reduction of the number of required passive elements. In addition, one current conveyor and an appropriate adder are required instead of the two current conveyors employed in the corresponding earlier topology. The second proposed all-pass filter has the attractive characteristic, in comparison with those already published in the literature, that only a single current conveyor is required. In both these configurations, a single grounded resistor is required as a passive element. Thus, these configurations can be made resistorless using metal-oxide semiconductor field-effect transistors and, also the condition of realisability can be electronically satisfied.