Patent ID: 7107555

Claim:
A method of designing a high-frequency circuit, comprising the steps of: setting up a circuit model wherein component items constituting a basic circuit are respectively replaced by component equivalent circuits having corresponding component items having frequency characteristics; performing calculation of evaluation data items for evaluating the component equivalent circuits in the circuit model, while changing frequency, by using a polynomial frequency function (Xsf): Xsf=Xs ( n )×Freq n +Xs ( n −1)×Freq (n−1) + . . . Xs (0), where Xs represents a parameter of an electric component, Freq represents a frequency, and n represents an integer of 2 or greater; obtaining the frequency characteristics of the component items of the basic circuit based on the evaluation data items; and using the obtained frequency characteristics to evaluate circuit characteristics; and, when a result of evaluation of the circuit characteristics indicates that targeted circuit characteristics are not obtained, replacing at least one of the component equivalent circuits in the circuit model by another component equivalent circuit corresponding to a component item having a different electrical characteristic, using the frequency function to calculate again evaluation data for evaluating the replaced component equivalent circuit, and evaluating again circuit characteristics by using frequency characteristics based on the calculated evaluation data items.