What are we talking by "completely awake" during the night?
I disagree that newborn babies are nocturnal in fact there is no difference at all between night and day for a newly born baby. Like when I'm the womb, a "fourth trimester" baby will spend short periods of time awake throughout 24h a day. But mostly baby will sleep most of the time.
In this fourth trimester phase, sleep is passive. So as long as all needs are met, baby will sleep. It could literally be a case of only 20-30 minutes of awake time between one nap and the next - 24 hours a day. And this awake time may be entirely be taken up by a feed, nappy check, quick cuddle, back to sleep. Wake and repeat. Wake and repeat. Wake and repeat.
So mainly baby's sleep is disturbed due to:
Hunger - feed very frequently. I'd go for every wake up, even if it's every 60-90 minutes thro the day.
Comfort - this could be a dirty nappy, too hot/cold, wanting closeness, wanting to comfort suck, not in pain.
Are you breast or bottle feeding?