By John Keller

ARLINGTON, Va., 5 April 2009. Scientists in the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., are looking to two U.S. defense companies to develop terahertz integrated circuit technology for military applications in advanced military imaging technology, radar technology, terahertz spectroscopy for chemical warfare detection, and military communications.

DARPA awarded three defense terahertz technology research contracts April 3 to two divisions of Northrop Grumman Corp., as well as to Science Applications International Corporation (SAIC) in San Diego to make revolutionary advances in developing electronic devices and integrated circuits that operate at terahertz frequencies.

The Northrop Grumman Electronic Systems segment in Linthicum, Md., won an $8.9 million contract, SAIC won an $11.6 million contract, and the Northrop Grumman Space and Mission Systems segment in Redondo Beach, Calif., won a $37.3 million contract.

The sub-millimeter wave (sub-MMW) frequency band between 0.3 to 3 terahertz historically has been extremely difficult because designers lack the means to generate, detect, process, and radiate radio-frequency (RF) signals in these frequencies, DARPA officials explain.

Military and aerospace applications that operate at terahertz frequencies need greatly improved terahertz transmitter and receiver technologies to be effective. That is where Northrop Grumman and SAIC experts come in.

For transmitters, DARPA primarily wants to develop higher power sources and amplifiers -- with acceptable wall-plug efficiency, instantaneous bandwidth, and gain -- than are available today.

DARPA experts say they have an opportunity improve noise figure and phase noise characteristics in future terahertz RF applications. Signal-to-noise ratio improvements of 70 decibels or more might be possible with spectral filtering and phase coherent processing techniques such as using coherent heterodyne processing that exploits the relative phases of transmit and receive signals.

A big drawback to terahertz electronics has been the lack of high-density integrated circuit technology. Achieving the level of integration necessary to enable practical terahertz systems, such as arrays, will require SAIC and Northrop Grumman to come up with methods for integrating devices into compact circuits.

Company scientists also must develop low-loss interconnects between circuit elements, which are essential for achieving acceptable performance.

Northrop Grumman and SAIC scientists will develop technologies for high-performance electronic circuits that operate at frequencies higher than 1.0 terahertz. These technologies will involve terahertz monolithic integrated circuits; terahertz inter-element interconnects; terahertz circuit integration; terahertz test circuit; and terahertz metrology.

Company scientists also will develop terahertz high power amplifier (HPA) modules, including terahertz power amplifiers; compact terahertz HPA module; and terahertz metrology.

In charge of this project is the DARPA Microsystems Technology Office (MTO). Supervising the program will be DARPA Program Manager Mark Rosker, who can be reached by e-mail at mrosker@darpa.mil, or by phone at 571-218-4507.

For more information contact the DARPA Microsystems Technology Office online at www.darpa.mil.