Embodiments of RF amplifiers and packaged RF amplifier devices each include a transistor with a drain-source capacitance that is relatively low, an input impedance matching circuit, and an input-side harmonic termination circuit. The input impedance matching circuit includes a harmonic termination circuit, which in turn includes a first inductance (a first plurality of bondwires) and a first capacitance coupled in series between the transistor output and a ground reference node. The input impedance matching circuit also includes a second inductance (a second plurality of bondwires), a third inductance (a third plurality of bondwires), and a second capacitance coupled in a T-match configuration between the input lead and the transistor input. The first and second capacitances may be metal-insulator-metal capacitors in an integrated passive device.