The 29 year old told BBC Radio Nottingham: "There was only one club I was going to if I was going to the Championship.
"They are packed with good midfielders, but I still wanted to come home and play for the club that made me."
England international Jenas, who left the City Ground to join Newcastle United in 2002, has been plagued by injuries in recent seasons and is desperate to get back to playing regular football.
"I want to say thanks to the fans for the reception they gave me after coming back following such a long time away," Jenas said.
"I have come here to play football. I had my bad Achilles injury and I want to get back playing again. It was nice to get out there and get a feel of the ball.
"I need games and we'll see what happens in the next few weeks but I am ready to go and eager to help out.
"I wanted this. I nearly did move to another Premier League club in January. It didn't quite happen and the phone was ringing from a number of Championship clubs.
"The club are going in the right direction. I started at the club when I was seven or something like that and came all the way through. It's good to be back and see some old faces and I am looking forward to playing some football now.
"I'm obviously not at the peak of my powers but I know I can add a lot to the team and know I will only get stronger and stronger with games."