I think you may find the answer of your question in the following link:

http://www-inst.eecs.berkeley.edu/~ee217/sp03/ADS/AgilentADSTutorial.pdf

The concept is explained in detail.

Regards,

sir file is helpful but i want to ask that can this s2p block works in momentum or not as i have to simulate a filter design in which i have to implement diode, i can use resistor and capacitors as equivalent circuits or s2p file of the used diode but in both cases i dont know will the effect in mommentum will be generated on not

momentum is a full wave solver which solves the wave equations on the desired structure  so it can't solve structures including blocks.

i think u can do as below:

1-simulate your structure without additional elements like diode and resistor. instead of these elements, put two ports at two ends of the elements

2- after simulating in momentum, export your results in touchstone format (snp)

3-  in schematic , import your results in a n-port block 

4- place your elements(diodes) at the proper ports

5- simulate your structure in schematic envirement

I think you are following a wrong direction. Momentum is used for EM simulations for the metal structures in layout. When you are provided with models for passive and active elements which has all this information included, why you want to do it in Momentum? Why dont you use them on schematic for simulations? Probably you can explain us better to help you.

I need to simulate the effects of diode , SKYWORKS, its model is not available in ADS. Momentum simulation is needed for full wave effects now there is a box lumped elements with artwork and s2p block in it , it also shown up in Momentum but i dont know its effect are working on simplification or now

I assume you filter simulation requires an EM analysis. This is done in Momentum and the resulting s2p file is now available for the filter from Momentum. Next, you need to generate a model for your diode, unless you have an s2p file for its electrical performance. Finally, concatenate the resulting s2p files to see the effect of the diode on the filter performance. All done in a conventional simulator with linear analysis. However, if you are interested in large signal effects, then you challenge will be to generate a large signal model for the diode or attempt to fit its parameters to one of the many Spice equivalent diode networks.

You can implemented diode model by PCB. After that if you want to know what is more accurate equivalent circuit of diode , you can extract input and output impedance from four types of scattering parameters (called S11 , S12, S21 and S22) by well known conversion formula which was published by David Pozar popular textbook in microwave engineering. After that you can use additional input matching and output matching circuit from floating RC parallel passive circuit which is simple diode model in frequency domain. This is another way of thinking without Momentum software