Scotland forward Shaun Maloney was brought in from Celtic for £1million, Spanish winger Albert Crusat arrived from Almeria and Holland Under-21 defender Patrick van Aanholt signed on a season-long loan from Chelsea.
All three could come into contention to make their debuts at Manchester City on Saturday.
Martinez said: "They have come in with a real desire to be here and first and foremost that is something we were looking for.
"The players that come to Wigan Athletic need to have a real hunger for wanting to join the football club.
"I can tell you Albert, Shaun and Patrick bring in something completely different.
"Now the competition for places is really strong.
"I am very pleased that we have finished the window and the squad is a lot stronger than when we started. That is our objective in every window.
"We are really excited with the three new faces."