Hi everyone,

I have been working on RF CMOS power amplifier for WLAN applications. I was trying to measure the evm of the design using envelope analysis in ADE L. In envelope analysis different levels were present. Using level-1 at 18dBm output power I am getting around 1.9% evm. With level-2 at 18dBm output power I was getting 3.5% evm. However, with the pure transient ( I mean marking the off option in envelope analysis), my evm is increasing drastically to 6.7% for the same output power.
I know the difference between level-1 and level-2 . But I have no idea, how level-2 is different from pure transient. Isn't level-2 evm result should be closer to pure transient one. If not, in which cases level-2 result will be different from pure transient.
If someone needs any additional information, please comment down below.

regards,
n@zgul