A switching amplifier (200; 300; 400; 500) comprising: a switch (202; 302) configured to electrically connect and disconnect a first pin (202a; 302a) of the switch (202; 302) to a second pin (202b; 302b) of the switch (202; 302) in accordance with a pulse width modulated input signal (216; 316; 516). The second pin (202b; 302b) is connected to a ground connector (204; 304). The switching amplifier also comprises a feed inductor (206; 306; 406) connected between a voltage supply connector (208; 308) and the first pin (202a; 302a) of the switch (202; 302), and a circuit (210; 310; 522) comprising a variable component having a variable imaginary impedance. The circuit (210; 310; 522) is connected between the first pin (202a; 302a) of the switch (202; 302) and an output connector of the amplifier (212; 312. The switching amplifier further comprising a controller (214; 314; 514) configured to generate a control signal (315; 515) for the circuit (210; 310; 522) such that the variable component of the circuit is adjustable in accordance with the duty cycle of the pulse width modulated input signal (216; 316; 516).