A new design for 4-bit RCA using quantum cellular automata technology

Abstract

Since the scaling of transistors is growing rapidly, the need for an efficient alternative for the Complementary Metal-Oxide-Semiconductor (CMOS) technology to obtain further and extra processes in the circuits has been known as the main problem. Over the last decade, Quantum-dot Cellular Automata (QCA) technology has been recognized as a suitable replacement for CMOS technology due to its excellent potential in developing designs with low-power consumption, high speed, and high density. In this regard, lowering the number of gates, the amount of cell count, and delay has been emphasized in the design of QCA-based circuits. As the main unit in logic circuits and digital arithmetic, adders play an important role in constructing various effective QCA designs. In this regard, Ripple Carry Adder (RCA) is a simple form of adders and, due to its remarkable features, can be useful to reach circuits with the minimum required area and power consumption. Therefore, this study recommends a new design for RCA in QCA technology to reduce the cell count, amend the complexity, and decrease the latency. To verify the correctness of the suggested circuit, the QCADesigner-E version 2.0.3 as a well-known simulator has been used. The evaluation results confirm that the proposed design has approximately 28.6% improvement in cell count compared to the state-of-the-art four-bit coplanar RCA designs in QCA technology. Also, the obtained results designate the effectiveness of the advised plan.