There are all kinds of creative ways of dealing with rogue drones: Radio jamming. Other drones with nets. Trained eagles. None of these are really designed to handle military drones, however, and large, fast-moving UAVs are still a potential threat, especially if more than one is coming at you at once. It's no surprise that the U.S. Army has been developing solutions for this potential threat— we're not sure what they're working on now, but as of late 2013, Raytheon was successfully testing a long range, high power directed microwave weapon capable of taking out swarms of drones in milliseconds.
The Phaser is essentially a high powered microwave (HPM) cannon that runs on a diesel engine. Exactly how powerful this thing is (and what its range is) is still classified, but we do know that it can be tuned to either "disrupt" or "damage," where for most drones, "damage" seems to be synonymous with "destroy." It's also effective against cars and other vehicles, and almost anything else that wouldn't work properly without functioning electronics.
No matter how heavily cooked you like your drones, microwaves can achieve the desired effect in milliseconds, which is a major advantage of the Phaser over laser weapons: lasers typically require several seconds to burn through a target, and it's very difficult to keep them focused on a small, fast moving, and far away point for that amount of time. One commonality that all directed energy systems have is their very low cost of operation, which is in the range of cents per firing, far cheaper than either projectile weapons or missiles.
Raytheon has plenty of experience with microwave weapons; they've been working on a non-lethal anti-human "Active Denial System" (ADS) for over a decade. From 250 meters away, the ADS can gently heat the water just under your skin with millimeter-wave radiation, making anyone standing in the beam feel like they're on fire. The feeling stops as soon as you get out of the beam, and there are otherwise no physical consequences. As of 2015, the U.S. Air Force was looking at mounting ADS systems on AC-130 gunships as a non-lethal crowd control option.
We're not entirely sure what the current status of the Phaser is, although Raytheon told Aviation Week that the system is now half the size it was in the 2013 test and could be ready for operational deployment in less than two years. At the rate drone technology is evolving and drone population is expanding, it seems likely that there will be a serious need for it by then.