Switching circuit and variable attenuator

A variable attenuator comprising:

• a switching circuit configured as a shunt circuit of the variable attenuator, the switching circuit including,
• a first switch connected in parallel with a first circuit element;
• and
• a second switch connected in series with a parallel circuit constituted by the first circuit element and the first switch;
• and
• a second circuit element connected in series with the first circuit element and the second switch,
• wherein the first switch and the second switch alternately perform on-off operation,
• the second switch has a parasitic reactance set in such a way that a parasitic reactance occurring at the parallel circuit in a first state in which the first switch is controlled to be off and the second switch is controlled to be on and a parasitic reactance occurring at the second switch in a second state in which the first switch is controlled to be on and the second switch is controlled to be off are equal to each other,
• the first switch is controlled to be off in the first state and to be on in the second state, and
• the second switch is controlled to be on in the first state and to be off in the second state.