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Measurements >> RF Measurements >> Load pull for differential PA
https://designers-guide.org/forum/YaBB.pl?num=1298729306

Message started by jeffrey-peng on Feb 26^th, 2011, 6:08am

Title: Load pull for differential PA
Post by jeffrey-peng on Feb 26^th, 2011, 6:08am

Hi,
When design PA , we use Load pull technique to find the best Load impedance to optimize efficiency and output power. It is easy to do Load pull test in single ended PA. How to do that differential PA with a balun to convert differential output to single ended? Where to put the adaptive load, before or after the balun? If before the balun, Do we need two adaptive load for each output. If it is behind the balun, how to move the matching network before the balun?

Title: Re: Load pull for differential PA
Post by purplewolf on Apr 2^nd, 2011, 6:08am

correct me if i am wrong...you design PA in a single ended configuration and optimize it with load pull to provide the optimum impedance conditions..once you are done, you just connect it in a differential manner to get 3 dB extra power and to reject common mode noise thorugh balun or a transformer.. i dont see any reason performing load pull on differential and not sure how to perform it..