Question about Hartley image reject mixer

[pigkiller]

since i use mixer with polyphase to suppress the image freq, i wonder if i have to use adder to sum it up?
if i have to use it, could anyone give me a specific example circuits of adder to implement in this situation?

 

[elbadry]

Are you using I-Q mixing?
And are you using a Gilbert Cell mixer?

If you use Gilbert Cell you can add the o/p's in the "current" domain simply by using a single load for both I and Q mixers.