Different limit structures?

Hey.
Normally limit will be played in increments of the small or big bet, like the betting is 100 -> 200 -> 300 and capped at 400.
But at the last tournament I've played the betting structure was 100 -> 200 -> 400 and capped at 800.
This makes a huge different in Pot Odds. So can someone tell me what this betting structure is calling? And is this a common bet-sizing in Limit?