Characterization and modeling of a step-gate-oxide MOSFET for RF power amplifiers

In this paper, we propose a low cost step-gate-oxide (SGO) MOSFET that is suitable for RF power amplifiers. Both simulation and experiment results approve the reduced parasitic capacitance, higher cutoff frequency and improved breakdown voltage. With optimized structure, we achieve 20% reduction of the feedback capacitance; increased breakdown voltage by 8% with higher cutoff frequency, which will allow more power to be obtained at higher frequency. Devices are fabricated on SOI wafers to verify the simulation result.