0.5 to 4.5 ghz limiter for 0dbm using PIN diode

Hello
could somebody help me to design a limiter using PIN diode to get flat leakage of 0dbm? Shall i go for multistage PIN diode or 1 PIN and 1 schottky diode?how does limiter output depends on frequency?
and how can i simulate it in ADS? I didnt find a PIN diode model? and which simulation component i need to use in ADS to see graph of Po vs PI?

I guess they do make such things:
http://www.herotek.com/datasheets/pd..._LL_Series.pdf
But they require dc bias, probably for op amps inside to turn on the limiter diodes.

Without DC bias, no can do.

hi
please study this handbook.it is very usful
www.qsl.net/n9zia/pdf/pin_diode_handbook.pdf

thank u for your reply and I'll go thr this link