amplifier ground at two source pins?

hi how i put the amplifier ground at its two source pins althougth,at ADS2003 the s parameter module contain only 3 terminas for gate,drain and source in other word how i simulate the amplifier with two source pins ground
regards

The model should contain the effects of the two source pins. This two pin arrangement is used to reduce the effects of the parasitic lead inductance of the package. This approximately halves the inductance.

thanks ,so at the designsimulation,the effect of the two pins appear in the results of s par .i design LNA at x band but after matching,the k<1,if i increase the pad of ground at source,the k be nearer 1.is that solution good.
regards