An aerosol-generating device for heating an aerosol-forming substrate to generate an aerosol is provided, the aerosol-generating device including: a substrate cavity configured to receive an aerosol-forming substrate; and an electromagnetic field generator including a solid state radio frequency (RF) transistor and being configured to generate a RF electromagnetic field in the substrate cavity. A method for generating an aerosol from an aerosol-forming substrate is also provided. An aerosol-generating article is also provided.