large signal input matching

[Cluny]

Hi, I want to do the input matching for a power amplifier. In addition there's a dynamic load at the output which change its value over the input power range. Thus, there's definitive a non-linear behaviour and I'm not sure for which "drive point" I should do sp simulation?

Do you have to optimize the small signal matching for maximum input drive or rather for the medium?

Or what would be your procedure for large signal input matching???

Thanks

 

[kspalla]

One should use load pull technique for large signal matching.

 

[ChaoFan]

input matching is easy, just use VNA to monitor the S11, the result is almost same as the large signal S11.

 

[vfone]

Only for a pure Class-A power amplifier the input return loss is not changing with input power. For Class-A power amplifier can be used S11 small signal s-parameters for designing the input matching.

For other power classes the input return loss will change (more ore less) with input power. So, you need to use a load pull (input and output) to find the optimum match for gain, output power, efficiency, linearity, etc.

 

[Cluny]

Yes, I have a Class-C power amplifier and I want to match the input for high power level...

I've found a solution... using psp simulation for different input power, especially input power level at maximum output power.

 

[TerryADS]

Can you share us your solution?
Thank you,