help with the design of a Diode Limiter

Hi guys,

I'm trying to design a limiter, and i'd appreciate some help.

I'm using the Skyworks CLA4603 Pin diode, it's supposed to limit starting from 10dBm and i'm working at 9.4GHz.
Now in my design i simply printed a Microstrip Line and i soldered the anode of the diode on the line and the cathode to the ground and i used two stages of this.

With the way my design is made i had 0.5 dB insertion loss, But it doesn't limit starting 10dBm, i have gone up tp 22dBm and the insertion losses remain the same.

I didnt simulate the design since i only have an S2p parameter File where the port 1 and 2 are the anode and the cathode is grounded so i didn't know how to use it to simulate what i wanted.

Any help or guidance would be appriciated.

Thank you in advance.

Skyworks doesn't provide Spice parameters for this diode, but you can use a Spice model from other PIN diode, just to see how your circuit works vs bias current.
At this frequency you may need impedance matching networks at the input and the output of the limiter.

http://gmcatalog.kratosmed.com/images/Catalog08/p019/p019_02.gif

I actually didn't need to use a matching network, since i did put a quarter wavelenght line between the two stages.

I'm sorry if this sounds like a dumb question, i really don't have much experience, but is a shunt component soldered the way i did it, or do i need to have a line coming down from my main microstrip (kinda like a T) ?
if it's the case why is the diode not limiting?