Frequency dependence of GaAs FET equivalent circuit elements extracted from the measured two-port S parameters

An eight-element equivalent circuit for GaAs FETs is used to calculate their element values from the eight measured data values of the two-port S parameters exactly at each frequency. Three element values vary with frequency and two additional small inductances are needed to account for the frequency dependence. A ten-element equivalent circuit including these correction inductances closely predicts the wafer measured S parameters up to 18 GHz.<
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