A power amplifier includes a semiconductor substrate including transistor cells, a drain electrode for the transistor cells located on the semiconductor substrate, a drain pad located on the semiconductor substrate and connected to the drain electrode, an ion-implanted resistance located in the semiconductor substrate and extending along and in contact with the drain pad, a floating electrode located on the semiconductor substrate and in contact with the ion-implanted resistance, and an output matching circuit located outside the semiconductor substrate. The power amplifier further includes a wire connecting the drain pad to the output matching circuit.