Amplifier modules and systems with ground terminals adjacent to power amplifier die

An amplifier module includes a module substrate with a mounting surface, a signal conducting layer, a ground layer, and a ground terminal pad at the mounting surface. A thermal dissipation structure extends through the module substrate. A ground contact of a power transistor die is coupled to a surface of the thermal dissipation structure. Encapsulant material covers the mounting surface of the module substrate and the power transistor die, and a surface of the encapsulant material defines a contact surface of the amplifier module. A ground terminal is embedded within the encapsulant material. The ground terminal has a proximal end coupled to the ground terminal pad, and a distal end exposed at the contact surface. The ground terminal is electrically coupled to the ground contact of the power transistor die through the ground terminal pad, the ground layer of the module substrate, and the thermal dissipation structure.