Graphene/Silicon-on-Insulator Heterogenous Cascode Amplifier With High Gain

Although graphene field-effect transistors (GFET) exhibit high carrier mobility and transconductance, they suffer from low output resistance, resulting in limited voltage and power gain. In this study, a heterogenous process is developed to integrate single-layer graphene with silicon-on-insulator (SOI) substrate, then achieving a groundbreaking high-gain cascode amplifier. By combining the advantages of high transconductance from GFET and high output resistance from SOI-FET, the heterogenous cascode amplifier shows high output resistance and high voltage gain. Moreover, the heterogenous cascode amplifier demonstrates a significant improvement in transconductance (12.6 times of SOI-FET) and output resistance (98.7 times of GFET). A maximum gain of up to 80 is obtained by optimizing the bias conditions, vastly exceeding that of standalone GFET and SOI-FET devices. This graphene/SOI heterogenous cascode amplifier exhibits promising applications in radio-frequency transistor technology and wireless communication.