Defense Advanced Research Projects AgencyTagged Content List

Electromagnetic Spectrum and Bandwidth

Novel concepts and technologies for maximizing use of the electromagnetic spectrum

Showing 37 results for Spectrum + News RSS
Military radars, military communications networks, and commercial communications networks all require increasing amounts of limited radio frequency spectrum. Balancing national security requirements of radars and military networks with the growing bandwidth demands of commercial wireless data networks calls for innovative approaches to managing spectrum access. DARPA’s Shared Spectrum Access for Radar and Communications (SSPARC) program aims to improve radar and communications capabilities for military and commercial users by creating technical solutions to enable spectrum sharing.
Phased radio frequency (RF) arrays use numerous small antennas to steer RF beams without mechanical movement (think radar without a spinning dish). These electronics are invaluable for critical DoD applications such as radar, communications and electronic warfare. Their lack of moving parts reduces maintenance requirements and their advanced electromagnetic capabilities, such as the ability to look in multiple directions at once, are extremely useful in the field. These benefits, though, come with a high price tag. Current phased arrays are extremely expensive and can take many years to engineer and build.
Two teams of DARPA performers have achieved world record power output levels using silicon-based technologies for millimeter-wave power amplifiers. RF power amplifiers are used in communications and sensor systems to boost power levels for reliable transmission of signals over the distance required by the given application. These breakthroughs were achieved under the Efficient Linearized All-Silicon Transmitter ICs (ELASTx) program. Further integration efforts may unlock applications in low-cost satellite communications and millimeter-wave sensing.
The military uses long-wave infrared (LWIR) cameras as thermal imagers to detect humans at night. These cameras are usually mounted on vehicles as they are too large to be carried by a single warfighter and are too expensive for individual deployment. However, DARPA researchers recently demonstrated a new five-micron pixel LWIR camera that could make this class of camera smaller and less expensive.
As wireless devices proliferate and the radio spectrum becomes ever more congested, all users have a common interest in radio technologies that can accommodate the largest number of users but still enable priority traffic to get through. The DARPA Spectrum Challenge—a competitive demonstration of robust wireless technologies—recently announced the selection of 15 of 18 semifinalists for $150,000 in prize money. DARPA plans to fill three remaining wildcard slots in August 2013 before the September 2013 semifinals at DARPA’s offices in Arlington, Va.