A device (50) provides a radiant electromagnetic energy output. During standby operation of the device (50), the output is provided at one or more frequencies selected to dissipate excess power through atmospheric absorption. Circuitry (56) is included to tune the output of the device to a second frequency different than the first frequency for various directed energy applications that make use of the excess power. The circuitry (56) can be arranged to further utilize frequency agility for power dissipation, to provide different operating modes involving a radiant output, or the like.