Design and 3-D Modeling of A GaN 3-Stacked-FET Power Amplifier

A 3-stacked-FET power cell for power amplifier is designed and fabricated based on a 0.1 μ m GaN process in this paper. To overcome the high frequency oscillation, a modified stacked structure has been proposed by adding a parasitic inductance to the inter-stage of the stacked-transistors. This power cell can delivers an unconditionally-stable small signal gain of 20 dB, 62% of the maximum efficiency and 5 W output power at 12GHz. Meanwhile, in order to achieve the reliability analysis, the 3-D model of this PA was built by manual drawing in ANSYS WORKBENCH. Thus, the 3-D model can be used to do further analysis.