GAL: A RF Effects Mitigation Technique for Radar and Communication Equipment

Feasibility of a GaAs adjustable limiter (GAL) integrated with a low-noise PHEMT amplifier will be demonstrated. Produced as a monolithic GAL/LNA and incorporated into radar and communication equipment front-ends, it will provide protection from damage and disruption by electromagnetic radiation and ESD. Phase-1 consists of four tasks: 1) design and fabrication of GAL prototypes, 2) testing of GAL prototypes, 3) design and performance modeling of the monolithic GAL/LNA for Phase-2, and 4) final report. First, prototype GAL units using power PHEMTs are designed and constructed using discrete components which are bond-wired together. Next, the GAL units are tested to assess their a) power-protection capability as a function of gate periphery and rf pulse width, b) adjustability characteristics (turn-on adjustment level and time required to vary this level), and c) operational lifetime. The noise parameters for the power PHEMTs used will be obtained. The test results will be used to design and model monolithic GAL/LNA units for fabrication and demonstration in Phase-2 and provide performance predictions for the monolithic GAL/LNA. The final report will document all work performed and provide a schedule and work plan to build and demonstrate a family of monolithic GAL/LNA units for use as commercial products. BENEFITS: A monolithic limiter/LNA with an adjustable turn-on threshold such as GAL provides cost effective, small size, and robust RF-protection capability. It meets the growing military need for radar and communication system RF protection and similar commercial needs to mitigate disrupting RF interference in the exploding wireless technology market. This program fosters an early implementation of this type of protection in COTS products for utilization by the military.