How to Setup and Run Load Pull Simulations: The Basics

[@anirbansengupta1693]

Hello Sir, This load pull experiment is done on a GaN HEMT device which is a voltage controlled device. If I suppose to run this same experiment on a Bipolar Junction transistor then we need to modify the load pull instrument's inherent setup to control the biasing current of base bias circuit. But for that case I am not getting the desired response of the transistor. Can you please give some insight on this problem? How can I use a BJT in this load pull template of ADS 2017?

[@chao.l6795]

great explanations! Thank you!

[@mohamedazizrifi2718]

Hello, Thank you for this video. At 2:02 you say "if the input signal is low and i'am assuming a large signal" you mean that you are working with a low value of input voltage at a specific moment "instantaneously"? thanks in advance

[@alirazasaleem3919]

Is this technique applicable to switch mode PAs?

[@oluseunwikiman]

how do you run load pull for a s stage amplifier not just a single transistor

[@jayzinho10]

Whats is the meaning of reference Z0?

[@shadabrabbani]

while performing load pull analysis sometimes i get -ve real part of input impedance for "load that gives maximum power (and gain)" while it is +ve for "load that gives maximum PAE". What is the reason behind this?

[@michaeladelman6255]

Hello Andy, Thank you for the tutorial, it's very helpful. Do you have pdf file that explains the equations in DDS window?

[@KeysightEEsofEDA]

+Michael Adelman No, we don't have a PDF. However, all of the data displaysin the Load Pull Design Guide have an “Equations” page, and Andy has added notes to all of them. We recommends starting with the HB1Tone_LoadPull data display file’s equation page. You can get it from any schematic by selecting: DesignGuide > Load Pull > One-Tone Load Pull Simulations > Constant Available Source Power.

[@sharyalzafar4772]

I'm not able to find Cree GAn HEMT. Can someone please tell me where can i find it?

[@massoudmassoud806]

is there a load pull for the highest IIP3?

[@AEHoward5357]

There are two-tone load pull simulations that produce contours of intermodulation distortion. Since IIP3 is an extrapolated value, assuming the device is not being driven too far into compression, I think plotting contours of IMD makes more sense. But why not plot contours of ACPR or EVM instead, (which we can do)?

[@massoudmassoud806]

Thank you for taking time and reply my comment. How can I pick the right load pull to have the highest linear for the system? Thank you again

[@AEHoward5357]

@@massoudmassoud806 You could use one of the two-tone load pull simulation setups in the ADS Load Pull DesignGuide. This will produce contours of intermodulation distortion. If you want to continue this conversation, please connect with me on LinkedIn. Thanks, Andy Howard