Here is a known microwave weapon: WB-I
Perhaps this or something similar?The device which is called WB-I is a non-lethal directed energy weapon. It uses high-power light waves to bring instant burning sensation to the targets and make the targets to run away. The effective emission radius of the weapon is 80 meters, which can reach one kilometer after increasing weapon's transmit power. The weapon can be used in anti-terrorism and anti-pirate operations.