Original Date: 05/01/2000
Revision Date: 01/18/2007

Previously at Northrop Grumman Defensive Systems Division (DSD), designing custom circuits and monolithic microwave integrated circuit (MMIC) prototypes were not cost-efficient practices. Time and associated cost were a significant part of the overall development cost, and prototyping required the maintenance of a large Research & Development stock. In the 1990s, the company developed MMIC design tools to improve these practices.

In 1992, Northrop Grumman DSD established the MMIC Cell Library which helped reduce the time and cost associated with designing custom circuits. Containing more than 300 of the most frequently used designs, the MMIC Cell Library facilitates MMIC cell reuse and minimizes circuit re-invention. In addition, the designer has access to all MMIC foundry process information required for reuse. The MMIC Cell Library enables the company to reduce its design time by one-third compared to the previous practice.

In 1996, Northrop Grumman DSD developed the Rapid Prototyping System which increased design and prototyping efficiency. The company implemented this prototyping method for fabricating MMIC-based subassemblies. A complete inventory of custom and off-the-shelf GaAs MMIC devices, components, and thin film networks is maintained in the MMIC Research & Development Prototype Laboratory. The Rapid Prototyping System enables the company to produce prototype MMIC hardware in a matter of hours for various internal and external customer requirements.

Additionally, Northrop Grumman DSD implemented a Peer Review Procedure for MMIC design that eliminates more than 90% of the design errors during tile creation. This procedure also eliminates about 15% of the design errors before tile design release, and complements the availability of the reference libraries. Designers have assigned mentors who guide them in the use of tools and practices. All libraries are electronically checked on a weekly basis for updates or changes. After a tile is created, a final layout design rule check is performed. Stream data is then converted back and again verified against the original data. Once the tile data is committed to fabrication, this data along with any modifications created at the foundry is stored in a reference library.

All MMIC design schematics, simulations, layouts, and subsequent measurements are documented in a MMIC library database. Since implementing its MMIC design tools, Northrop Grumman DSD has decreased design cost by 20%; design cycle time by 40%; manufacturing cost by 40%; manufacturing cycle time by 40%; and inventory by more than 30%.

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