Analysis of Low Phase Noise Graphene Oscillation Characteristics Under DC Bias in Phase-Locked Loop

In this brief, the oscillation characteristics of multilayer graphene are verified and analyzed by simulating and fabricating a multilayer graphene oscillator with low phase noise. Graphene has strong nonlinearity. Biasing can change the in-band conductivity of graphene. With electromagnetic excitation and DC bias circuit, multilayer graphene can be approximated as a series-parallel connection of multiple discrete element resistors and inductors, which can be used to make resonant circuits. In this brief, we first analyze the principle of bias voltage to change the surface conductivity of graphene, and establish a multilayer graphene Symbolically Defined Devices (G-SDD) simulation model based on the surface conductivity. When the G-SDD model is applied to the oscillator simulation circuit, the simulation results obtained are basically consistent with the experimental results. The multilayer graphene oscillator has an oscillation frequency of about 650 MHz, an output power of 6.48dBm, and a phase noise of −116.40dBc/Hz@1MHz. By comparison with other recent literature the better phase noise characteristics of this design are further highlighted.