A discrete capacitance switching circuit includes a DC decoupling capacitor connected between a power node that receives an AC signal and a first node, a diode connected between the first node and a second node, a unit capacitor connected between the second node and a reference node that receives a ground voltage, and a bias circuit. The bias circuit is configured to apply a first DC voltage to the first node and apply a second DC voltage to the second node. The applied first and second DC voltages control a switching operation of the diode.