Is there any word with the same meaning as imminent, with a positive connotation? The sentence is " This discovery has an imminent impact on the technology".
Is imminent itself appropriate?
Imminent does not have a positive or negative connotation, in my experience. It simply means that something is about to happen. So imminent impact is appropriate if you mean to say that the impact will happen within a short time, regardless of whether the impact will be positive or negative.