mixer output

[zxcv2201]

I am analyzing the results when I put a sine wave with a frequency of 8GHz to the LO and RF of the mixer.

At this time, I thought that it should have a maximum value if it has the same phase and a minimum value if it has an opposite phase. However, the DC level result was as follows.
(The circuit is a gilbert mixer with a current bleeding circuit and an RC parallel filter on the load stage)

- When having the same phase: -#mV
- With opposite phase: +# mV

I think it should have a positive maximum when it's in phase, but I'm curious as to why the opposite trend is coming out.

 

[FvM]

The expected result could be observed with a single quadrant mixer, but not with balanced (4 quadrant mixer). Consider sin(-x)*sin(x) = -sin(x)*sin(x). Or sketch the multiplied waveforms.