where does the reflected power goes in microwave ckts

suppose we have a band reject filter the center frequency is 4Ghz now if we input this frequency the power will not reach at port 2 instead it will be reflected at port 1 as at this freqency s11 will be near 0dB so where does this power goes.

Hi
I think this power reflected back to generator and lost on generator impedance

have u read this some where. Cause i also think in same way.