Fractional-order calculus has been used for generalizing many modern and classical control theories including the well establish PID paradigm. The obtained controllers, of non-integer order, must be approximated with high order integer ones, in order to be realized. Successively, analog or digital implementations are used for the real world applications. This approach offers the hip to a classical criticism to fractional calculus. Why design a fractional-order system, which is usually of low order, if you need a high order system to implement it? In order to face this problem, in this paper, a fractional-order capacitor, more specifically a Constant Phase Device, is applied for implementing a first order fractional transfer function. Due to the intrinsic nature of the realized device, just one capacitor is needed for the implementation, avoiding therefore the need of high order RC approximation. Furthermore a fractional-order Wien oscillator and a chaotic Duffing circuit are presented confirming the potentiality of the proposed device in realizing fractional order circuits.

分数阶演算已被用于概括许多现代和经典控制理论，包括完善的PID范例。为了实现，所获得的非整数阶控制器必须用高阶整数近似。相继将模拟或数字实现用于实际应用。这种方法为分数阶微积分提供了经典的批评。如果您需要一个高阶系统来实现它，为什么要设计通常是低阶的分数阶系统呢？为了解决这个问题，在本文中，分数阶电容器，更具体地是恒定相位器件，被用于实现一阶分数阶传递函数。由于所实现设备的内在本质，实施只需一个电容器，因此避免了高阶RC近似的需要。此外，提出了分数阶维恩振荡器和混沌Duffing电路，证实了所提出的器件在实现分数阶电路中的潜力。