The invention relates to RF power transistors with impedance matching circuits, and methods of manufacture thereof. Embodiments of an RF amplifier include a transistor (120, 220) with a control terminal and first and second current carrying terminals, and a shunt circuit coupled between the first current carrying terminal and a ground reference node. The shunt circuit is an output pre-match impedance conditioning shunt circuit, which includes a first shunt inductance (134, 234, 434), a second shunt inductance (135, 135,235, 435, 935, 935') and a shunt capacitor (142, 142',342, 442) coupled inseries. The first shunt inductance (134, 234, 434) comprises a plurality of bondwires coupled between the first current carrying terminal and the second shunt inductance, and the second shunt inductance (135, 135',235, 435, 935, 935') comprises an integrated inductor coupled between the first shunt inductance and a first terminal of the shunt capacitor (142,142',342, 442). The shunt capacitor is configured to provide capacitive harmonic control of an output of the transistor (120, 220).