A system, method and non-transitory computer-readable medium utilize an equivalent circuit model in which electrostatic capacitance changes in response to an arbitrary DC bias voltage applied to a capacitor from the outside. The equivalent circuit model includes a capacitor equivalent circuit section composed of a base circuit and a multistage circuit, a reference current generator section that calculates a reference current, a multiplying factor generator section that calculates a multiplying factor, and a current source current generator section that generates a current of the current source based on the reference current and the multiplying factor. The multiplying factor generator section generates a voltage of an nth-degree polynomial corresponding to the DC bias voltage when applying the DC bias voltage, and defines a current to be generated when the generated voltage is applied to a resistance as the multiplying factor.