2 January 2014

AFRL’s Defense Production Act Title III program for X-band GaN MMICs completed

A government and industry team led by engineers from the US Air Force Research Laboratory’s Materials and Manufacturing Directorate (AFRL/RX) has completed a program to assess, improve, refine and validate a domestic source of supply for X-band gallium nitride (GaN) monolithic microwave integrated circuits (MMICs).

Because GaN enables devices and MMICs with improved power, efficiency and bandwidth, MMICs offer the highest level of integration and the smallest form factor and they have become the technology of choice for power amplifiers and radars. MMIC technology typically provides better high-frequency performance by reducing parasitic circuit elements and provides enhanced reproducibility as a result of uniform processing and integration of all circuit elements.

GaN products include power amplifiers (PAs) and supporting MMIC solutions, such as low-noise amplifiers (LNAs), driver amplifiers and limiters. GaN power amplifier technology significantly enhances military capabilities by increasing radar ranges, sensitivity and search capabilities compared with existing radar platforms based on other semiconductor technologies. Additional defense applications for GaN MMICs include communication systems, electronic warfare (EW) applications, imaging, and sensor systems.

The Manufacturing and Industrial Technologies Division (AFRL/RXM) Defense Production Act (DPA) Title III team is responsible for conducting this work. Title III is a US Department of Defense (DoD)-wide initiative under the Deputy Assistant Secretary of Defense, Manufacturing and Industrial Base Policy (MIBP). The Air Force serves as the Executive Agent for the Title III Program within the DoD, and the Title III Program Office is located at Wright-Patterson Air Force Base (AFB) in Ohio as a component of AFRL/RXM.

“The Title III Program is a government-funded venture that aides manufacturers who specialize in materials used for defense applications,” says RXM engineer Jeffrey Smith, who serves as Air Force Executive Agent Program Manager. “Production capabilities that would otherwise be inadequate are transformed to support the material requirements of defense programs in a timely and affordable manner,” he adds.

Smith notes that Title III focuses on materials and components that could be used in a broad spectrum of defense systems. “The direct and indirect benefits to defense programs resulting from Title III initiatives are substantial, and Title III projects create numerous economic and technological benefits for domestic industries and consumers.”

DPA Title III engineers worked with Raytheon of Waltham, MA, to execute the program at its Compound Semiconductor Foundry, located within its Integrated Air Defense Center (IADC) in Andover, MA. Raytheon has a broad international and domestic customer base, including the US Missile Defense Agency, the US Armed Forces, and the Department of Homeland Security. In addition, its IADC facility is a DoD Category 1A Trusted Foundry (the highest category awarded), and is recognized for providing trusted, national security critical components. Its foundry employs 30 researchers and 100 device, circuit and module engineers in addition to many production staff operating a 23,000ft2, Class-100 cleanroom facility.

The Title III project achieved the primary objective of improving and maturing the production of GaN MMICs by producing a manufacturing process capable of low-rate initial production (LRIP).

“The project achieved a Manufacturing Readiness Level of 8, meaning the fabrication processes are ready for LRIP for insertion into defense systems,” says Dr Gene Himes, the AFRL/RXM program manager for the initiative. “When comparing the final results to the baseline Manufacturing Readiness Assessment, Raytheon exceeded all threshold yield key performance parameters, resulting in a three times improvement in product yield and a 76% cost reduction for its GaN MMICs.”

In addition to yield improvements, the team logged more than 1 million hours of reliability testing over the course of the project. Comprehensive reliability testing helped to eliminate early MMIC failures and exceed the median time to failure (MTF) key performance parameters by 1000 times.

Raytheon engineers also enhanced their GaN MMIC computer design model, which resulted in first-pass design successes, robust models incorporating temperature and process variations, and comprehensive design kits for use in two separate software packages.

“This program exploited the material properties of GaN semiconductors to enable devices and MMICs with higher power, higher efficiency and bandwidth, and superior performance than existing semiconductor technologies," Himes concludes.

See related items:

US government honors Raytheon for completing Title III GaN production improvement program

Tags: AFRL Raytheon X-band GaN MMIC Title III

Visit: www.wpafb.af.mil/afrl

Visit: www.raytheon.com