Despite defeat at home to Everton, Newcastle will still be in the elite competition next season.
"Yes, it is going to be a big transfer window," Howe said. "It's difficult to say on numbers, but I do think it's a window that we have to be active in and I'm sure we will be.
"The power of the Champions League and the pull of the Champions League is huge and we can't get away from that, the excitement that this will bring for the people here.
"And of course it's a selling point for us now, it's an opportunity for us to sell that dream to future players that might be considering coming to us."
Now better prepared
Howe is confident they will have learned from this past season's Champions League campaign.
He added, "The experience we had there the first time will help us no end, I think.
"We felt we grew through the competition, so I think we are stronger. I think we are better prepared both physically and mentally for the competition ahead."