“…Nowadays, the current conveyor has evolved into three generations with direct and inverting characteristics (Tlelo-Cuautle, Sánchez-López & Moro-Frias, 2010). All kinds of current conveyors work in mixed-mode and basically they are composed of unity gain cells (Soliman, 2009;Tlelo-Cuautle, Duarte-Villaseñor & Guerra-Gómez, 2008), which can be superimposed (Tlelo-Cuautle, Moro-Frias & Duarte-Villaseñor, 2008) to generate different kinds of active devices (Biolek et al, 2008), all of them useful for analog signal processing applications. Among the unity gain cells, the voltage mirror (Tlelo-Cuautle, Duarte-Villaseñor & Guerra-Gómez, 2008) and current mirror can be modeled by using nullators and norators (Tlelo-Cuautle, Sánchez-López, , but also they have the pathological representation introduced in (Saad & Soliman, 2010), and they can be used to model the behavior of active devices with inverting characteristics.…”