RF Blockset SPST Insertion Loss

I am experimenting with the insertion loss of the RF switch models provided in the RF Blockset. I created a simple model where I insert a constant signal into the SPST switch input and measure the power on the switch output. I keep the switch turned on and verify that the output power is correct. Afterwards, I tried to experiment with different insertion loss values to see the impact. Interesting enough, no matter what insertion loss value I use, the signal power did not change. I swapped out the switch with an attenuator and then I was able to see changes. For example when using a value of 3dB, I noticed a drop of half the power. Has anybody had similar experiences with the RF Blockset switch models?

[MathWorks RF & Mixed-Signal Products Team]

Hi Omar,

Thank you very much for you message. Indeed there is a problem with the SPST (Single Pole Single Throw) RF Blockset model when specifying the insertion loss. The development team is currently investigating the problem, we will post a solution as soon as possible.

As a quick approximation (the actual formulation is more complex), you can use this formula when specifying "resistance" characterization:

Ron = Rload*(10^(InsertionLossdB/20)-1)

Apologies for any inconvenience and thanks for pointing out this problem, it is very helpful to improve RF Blockset.

With best regards, Giorgia