Limited Scope
If what you are looking for is a campaign with a level cap, then you're looking for a limited scope campaign. In this sort of campaign, you need to build it around the levels at which you want characters to start and finish. In 4e, levels are broken into three distinct tiers of play. The tiers consist of ten levels and are named; Heroic (levels 1 to 10), Paragon (levels 11 to 20) and Epic (levels 21 to 30). In a limited scope campaign, just select one of the tiers and build your campaign around it.
Limited Time
Perhaps your group doesn't have much time to play on a regular basis. In this instance, you want a short preparation type of campaign. Fortunately, Wizards of the Coast produce their own pre-made adventures that can link together and form a campaign. Consider purchasing these and using them for the group. Not only is the adventure pre-made, but also so are the characters, making these adventures useful to avoid a long set-up session building characters.
Taking a Break
Perhaps your group is starting to burn out on your current campaign and are looking for an alternative. In this case, run a different type of campaign. If your regular campaign is a gritty, realistic world, focus a campaign around something light and fantastical. If you run a campaign with lots of politics in an urban area, run a short campaign that is nothing more than an extended dungeon crawl. A dungeon crawl is just a series of dungeons, one after the other, where the players don't have to do a lot of thinking beyond what monster they're going to hit next.
General Ideas
The subject matter of short campaign is only limited by your imagination. Because it is limited, you can do whatever you want with it. If you're playing a short epic tier campaign, you can fight the gods themselves, and not have to worry about the repercussions on your own world. Perhaps you don't have a lot of time, but your players have already run the regular 4e pre-made adventures. Look back to older editions, changing the monsters to fit the new leveling schemes. Subtle changes can make a campaign based on a well-known novel have a familiar feel without being a carbon copy.