Defense Advanced Research Projects AgencyTagged Content List

Electromagnetic Spectrum and Bandwidth

Novel concepts and technologies for maximizing use of the electromagnetic spectrum

Showing 101 results for Spectrum RSS
Reliable wireless communications today requires careful allocation of specific portions of the electromagnetic spectrum to individual radio networks. While pre-allocating spectrum is effective in benign environments, radios remain vulnerable to inadvertent interference from other emitters and intentional jamming by adversaries.
In the 1940s, researchers learned how to precisely control the frequency of microwaves, which enabled radio transmission to transition from relatively low-fidelity amplitude modulation (AM) to high-fidelity frequency modulation (FM). This accomplishment, called microwave frequency synthesis, brought about many advanced technologies now critical to the military, such as wireless communications, radar, electronic warfare, atomic sensors and precise timing.
Since its inception in 1992, DARPA’S Microsystems Technology Office (MTO) has helped create and prevent strategic surprise through its investments in compact microelectronic components such as microprocessors, microelectromechanical systems (MEMS), and photonic devices. MTO’s revolutionary work applying these advanced capabilities in areas such as wide-band gap materials, phased array radars, high-energy lasers and infrared imaging have helped the United States establish and maintain technological superiority for more than two decades.
Many existing compact, high-data-rate millimeter-wave wireless communications systems use integrated circuits (ICs) made with gallium arsenide (GaAs) or gallium nitride (GaN). These circuits provide high power and efficiency in small packages but are costly to produce and difficult to integrate with silicon electronics that provide most other radio functions. Silicon ICs are less expensive to manufacture in volume than those with gallium compounds but until now have not demonstrated sufficient power output and efficiency at millimeter-wave frequencies used for communications and many other military applications, such as radar and guidance systems.
DARPA yesterday issued a solicitation for proposals responsive to its Spectral Combs from UV to THz (SCOUT) program, which seeks new capabilities for highly sensitive remote detection of multiple biological or chemical agents in liquid or gaseous forms. A proposers day is set for Oct. 15 via webcast.