Step recovery diode model in ADS2005A

Hi,

I have a Step Recovery diode with the following parameter:

Vbr=20V
Cj6=0.5pF(max)
Rs=0.8ohm
tt=50ps
tL=15ns

Which component should I use to model such device since there is no exact SRD model in ADS2005A.

Please help

ttse7