Multi-Swarm Optimization of a Graphene FET Based Voltage Controlled Oscillator Circuit

The lack of well defined abstraction levels and immature design tools have made the custom design and optimization of analog circuits slow, complex and laborious. Furthermore, CMOS technology beyond 10 nm faces fundamental limits which may restrict its applicability for future devices. In this paper, a Graphene Field Effect Transistor (GFET) based cross-coupled LC circuit is used as case study to design a mixed-signal integrated circuit. A Multi-Swarm Optimization (MSO) algorithm is used for fast exploration of the design space for the GFET based LC-VCO to maximize its operating frequency given phase noise and power dissipation as optimization constraints. The length (L) and width (W) of the graphene channel are selected as the design variables. The phase noise is kept below -80 dBc/Hz and power dissipation is less than 16 mW. The design optimization flow results in a maximum frequency of 2.58 GHz for L = 3.35 mu m and W = 1.82 mu m and the phase noise and power dissipation constraints are well below the guard limits.