When applying evolutionary algorithms to circuit design automation, circuit representation is the first consideration. There have been several studies applying different circuit representations. However, they still have some problems, such as lack of design ability, which means the diversity of evolved circuits was limited by the circuit representation, and inefficient transformation from circuit representation into SPICE (Simulation Program with Integrated Circuit Emphasis) netlist. In this paper, a novel tree-based circuit representation for analog circuits is proposed, which is equipped with an intuitive and three-terminal devices friendly mapping rule between circuit representation and SPICE netlist, as well as a suitable crossover operator. Based on the proposed representation, a framework for automated analog circuit design using genetic programming is proposed to evolve both the circuit topology and device values. Three benchmark circuits are applied to evaluate the proposed approach, showing that the proposed method is feasible and evolves analog circuits with better fitness and number of components while using less fitness evaluations than existing approaches. Furthermore, considering physical scalability limits of conventional circuit elements and the increased interest in emerging technologies, a memristor-based pulse generation circuit is also evolved based on the proposed method. The feasibility of the evolved circuits is verified by circuit simulation successfully. The experiment results show that the evolved memristive circuit is more compact and has better energy efficiency compared with existing manually-designed circuits.

在将进化算法应用于电路设计自动化时，电路表示是首要考虑因素。已经有几项研究应用了不同的电路表示。但是，它们仍然存在一些问题，例如缺乏设计能力，这意味着进化电路的多样性受到电路表示的限制，以及从电路表示到SPICE（具有集成电路重点的仿真程序）网表的转换效率低下。在本文中，提出了一种新的基于树的模拟电路电路表示，它配备了电路表示和 SPICE 网表之间直观且三端设备友好的映射规则，以及合适的交叉算子。根据建议的表示，提出了一个使用遗传编程的自动化模拟电路设计框架，以发展电路拓扑和设备值。应用三个基准电路来评估所提出的方法，表明所提出的方法是可行的，并且改进了具有更好适应度和组件数量的模拟电路，同时使用比现有方法更少的适应度评估。此外，考虑到传统电路元件的物理可扩展性限制以及对新兴技术的兴趣增加，基于所提出的方法也发展了基于忆阻器的脉冲发生电路。通过电路仿真成功验证了演进电路的可行性。