Defense Advanced Research Projects AgencyTagged Content List

Electromagnetic Spectrum and Bandwidth

Novel concepts and technologies for maximizing use of the electromagnetic spectrum

Showing 22 results for Spectrum + SWAP RSS
Listen to a podcast featuring MTO program manager Dev Palmer as he talks about turning an early interest in the vacuum tubes of his guitar amplifiers into a career as an electrical engineer. His mission? To push electronic and electromagnetic technology along new frontiers that could lead to more capable radar, electronic warfare, and communications systems, and even to entirely new technologies.
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 submillimeter wave, or terahertz, part of the electromagnetic spectrum falls between the frequencies of 0.3 and 3 terahertz, between microwaves and infrared light. Historically, device physics has prevented traditional solid state electronics (microchips) from operating at the terahertz scale. Unlocking this band’s potential may benefit military applications such as high data rate communications, improved radar and unique methods of spectroscopy—imaging techniques that provide better tools for scientific research. However, access to these applications is limited due to physics.
High-energy lasers (HEL) have the potential to benefit a variety of military missions, particularly as weapons or as high-bandwidth communications devices. However, the massive size, weight and power requirements (SWaP) of legacy laser systems limit their use on many military platforms. Even if SWaP limitations can be overcome, turbulence manifested as density fluctuations in the atmosphere increase laser beam size at the target, further limiting laser target irradiance and effectiveness over long distances.