peak evm

Usaully the Peak EVM is about 2~4 times of EVM, I know the EVM is contributed by the PN,Filter,nonlinearity,Amplitude/Phase imbalance,Lo leakage...etc, but I want to know why the Peak EVM is 2~4 times of EVM, can you help me ?

thank you !

Peak EVM is instantaneous magnitude. EVM is mean value.