If a modulated signal with bandwidth=10MHz (0-10MHz signal bandwidth) enters the quadrature up-conversion mixer, what is the output signal like at the single ended output. Does it contain two 10MHz bandwidth at the left hand side of the LO and right hand side of the LO respectively? I mean there are one at 990MHz-1GHz and another one at 1GHz-1.01GHz (assume LO=1GHz). If this is correct, I have a question. As I just give a single tone into the quadrature input of the up-conversion mixer, the single ended output just could see the LO+RF tone and the LO-RF tone will be cancel out. Then, which one is correct?