Question about 25% duty-cycle LO IQ Up-Mixer！ any ref。 paper？

Question about 25% duty-cycle LO IQ Up-Mixer！
1. 25% duty-cycle LO Up-Mixer provide extra 3dB gain，why?
2. IQ up-mixer can provide another 6dB gain just for its I/Q property?

路过同问

too simple sometimes naive
1. check every paper which mentioned 25%LO
2. of course NO, sin+cos=sqrt(2)sin, so, 3dB

1. 25% duty cycle LO has higher gain than that of 50% duty cycle LO because LO overlap does not exist in switching pair.
2. NO, it's 3-dB gain in theory.