Gain Compression at Saturation

Hi Tina,

                       For the HMC788A, gain is ~ 2dB compressed at saturation. theHMC8411 & HMC637B are also `2dB compressed at saturation.

Regards,

Jim B

Should I just put 2dB?

Here is the power plot characteristics after changing it to 2dB. Please let me know if the plot makes sense. Thanks!

Hi Tina26,

                Which amplifier is plotted in the attached graph?

Regards,

Jim B

This is for the HMC8411 and here are my settings: 

Hi Tina, 26,

                     What frequency is that plot at?   Attached is a power sweep of the HMC8411 at 10 GHz using ADI's sys-parameter model. Do you have Genesys or SystemVue available to use? 

I can also provide you the nonlinear model, (spread sheet based), for you to import into your tool.

Regards,

Jim B

Hi Jim,

Operation frequency is at 4.3GHz. Unfortunately, I don't have Genesys or SystemVue, I am only using MATLAB for this simulation. I have downloaded the s2p file from Analog website and the image above for the non-linearity settings are the values I need to make an accurate plot for power. 

Thanks!

Hi TIna26,

                    Have you used ADIsimRF? It may be useful for you. It is a free tool. I've attached the links below. I've also attached the nonlinear model for the HMC8411. The HMC8411 is also in the ADIsimRF.

https://www.analog.com/en/lp/resources/adisimrf.html

https://adisimrf.download.analog.com/ADISimRF/publish.htm

Regards,

Jim B

HMC8411LP2FE_RFAMP_Model.zip

Hi Jim,

Will try to look into using this tool. 

Also, I would like to ask if you can give idea for calculations for input power and power back off in order to maintain the linearity of the amplifier. See image below for the simple calculations I made, kindly correct if this is wrong. 

Thanks!

HI Tina26,

                      Yes, that sounds correct.

Regards,

Jim B

Hi Jim,

Thanks for the confirmation. I am trying to design a three-stage amplifier by using these 3 components. Should I do impedance matching on each stage? Or should I just add LC circuit on the 1st and final stage? 

Thanks,

Tina