High-performance adder using a new XOR gate in QCA technology

Quantum-dot Cellular Automata is one of the new nanoscale technologies that have been offered as a viable replacement for CMOS. QCA technology has many attractive features in terms of speed, size and power consumption. These features allow the technology an opportunity to be suitable for replacing CMOS technology. In the digital system, the adder circuit is important to do all arithmetic operations such as division, multiplication and subtraction. Therefore, this work introduces a new layout of full adder in QCA technology. The proposed design is built using a novel structure of a 3-input XOR gate. Then, the suggested adder is used to build an 8-bit Ripple Carry Adder (RCA). The presented full adder in this work provided 25%, 30%, and 78% improvement in terms of cell count, area, and cost, respectively, while the suggested 8-bit RCA gives 67%, 25%, 11% and 80% improvement in terms of cell count, area, delay and cost, respectively. In terms of total power consumption, the significant advantage offered by the proposed adder is energy-saving as it reduces the total dissipated energy by 26%, 37% and 45% at three levels of tunneling energy (0.5 Ek, 1 Ek and 1.5 Ek), respectively. The QCADesigner tool v2.0.3 has been used to design and simulate all circuits in this work and QCAPro tool is used for power calculations.