Overview of Department of Defense Use of the Electromagnetic Spectrum [Updated July 16, 2021] [open pdf - 2MB]
From the Introduction: "The Department of Defense (DOD) is the largest federal user of the electromagnetic spectrum ('the spectrum'). It holds frequencies across multiple bands to support a number of technologies and uses. DOD utilizes spectrum on a day-to-day basis, for training, and for military operations. Thus, any changes to spectrum could affect DOD operations, both domestically and with allies abroad. Further, DOD has invested significantly in spectrum-dependent technologies. A summary of some of these technologies, including wireless communications, satellites, radar technologies that support situational awareness, signal intelligence and electronic warfare technologies, is provided [herein]. Changes in spectrum may affect how DOD can use, manipulate, or develop these technologies."
CRS Report for Congress, R46564
Congressional Research Service: https://crsreports.congress.gov/