Design and simulation of assorted functional QQCA circuits

Functional circuits are a group of combinational logic circuits which may be utilized for certain tasks and with specific planning. Decoders, multiplexers, and demultiplexers are all functional circuits that come in useful when creating complex systems. Quantum-dot cellular automata (QCA) is a flourishing technology that would be so practical in the field of computational digital circuits in terms of its advantages such as low energy consumption. This paper proposes various quaternary 1:4 decoders (enabling decoder, active-high and active-low decoders). Then, 4:1 multiplexer and 1:4 demultiplexer were architectured using the proposed 1:4 decoder. In the following, a quaternary to the binary converter (a 4-valued digit to a 2-bits circuit) is designed regarding the validated proposed structures. All designs were simulated and verified by QCASim. The total area used for the decoder, multiplexer, demultiplexer, and quaternary to the binary converter are 0.01, 0.19, 0.03, 0.13 μm². The complexity and delay are 30, 387, 88, 214 and 0.5, 3.25, 1, 2 respectively. This work gets compared to CMOS and carbon nanotube field-effect transistor articles. Furthermore, the proposed 4:1 quaternary QCA multiplexer got compared with the binary QCA multiplexers. The comparison results show that our proposed designs are efficient in terms of having a low delay, area, and complexity.