Schalke beat Valencia in the round of 16 and then crushed holders Inter Milan to book their first ever semi-final spot.
Ferguson was in the stands of the Auf Schalke arena for the return leg against Inter and said he was impressed by how the Gelsenkirchen-based side handled the game.
"The first thing is that they never looked like losing the game (against Inter). They were in complete control. It was a good impression," he told a news conference.
"I think you always get apprehensive at this stage of the competition. We had the same situation in the past against Juventus or Barcelona, where we played very well away from home but in the return leg it was pure agony, absolute agony."
Although their most famous victory came over Bayern Munich in the 1999 final, United have lost all four of the two legged knockout ties they have played against German sides since the start of the Champions League in 1992.
"They have a self determination, the German people have, and it is reflecting the way they are approaching all the sports," he said.
"There is a similarity with English people, maybe more with Scottish. We have this determination in Scotland, like I have, although I am more mellow now," he said with a dry smile.
NEVER GIVE UP
Nevertheless Ferguson reckoned his team were looking good after making their fourth semi-final in five years.
"This is a team that will not give in. Absolutely no chance that this team will give in," he said.
"The present group has enough experience now in Europe. I think it is where we should be. Expectations from my point of view are high. You get envious of other clubs so we try to get parity with that, with Real, AC Milan, Ajax."
Ferguson, bidding for his third Champions League title and United's fourth, said criticism early in the season regarding their away form was in part unjustified given they have kept a clean sheet in all their Champions League away games this term.
"I think it was a wee bit misguided, the criticism referring to our away form. Our home form has been absolutely sensational. If you talk about away form (earlier in the season) you can see the criticism but not all the time," he said.
Several key players including Rio Ferdinand, Antonio Valencia and Park Ji-sung are all back fully fit, swelling Ferguson's options.
"It's important when the big, big competitions come along that all your players are fit and you have a selection problem. That's good," said the Scotsman, who also felt striker Wayne Rooney was peaking at just the right time.
"I think Wayne's form has been absolutely fantastic for the past two months. I think good players create their own platform in the sense of importance. There is a lot of expectation of the boy. He stepped up to the bat for that," he said.
As for who he would prefer in the final - Real Madrid or Barcelona - should United advance, Ferguson said: "I don't like jumping ahead. We first have to deal with Schalke, then we will see."
