Dual-band semiconductor RF amplifier device

There is described a dual-band semiconductor RF amplifier device. The device comprises (a) a transistor (205) having an output capacitance (C O ), (b) a first shunt element (210) arranged in parallel with the output capacitance, the first shunt element comprising a first shunt inductor (L 1 ) connected in series with a first shunt capacitor (C 1 ), and (c) a second shunt element (220) arranged in parallel with the first shunt capacitor, the second shunt element comprising a second shunt inductor (L 2 ) connected in series with a second shunt capacitor (C 2 ), wherein the capacitance of the second shunt capacitor (C 2 ) is at least two times the capacitance of the first shunt capacitor (C 1 ). Furthermore, there is described a method of manufacturing a dual-band semiconductor RF amplifier device and a dual-band RF amplifier comprising a plurality of such amplifier devices.