The 60 GHz solid state power amplifier

A new amplifier architecture was developed during this contract that is superior to any other solid state approach. The amplifier produced 6 watts with 4 percent efficiency over a 2 GHz band at 61.5 GHz. The unit was 7 x 9 x 3 inches in size, 5.5 pounds in weight, and the conduction cooling through the baseplate is suitable for use in space. The amplifier used high efficiency GaAs IMPATT diodes which were mounted in 1-diode circuits, called modules. Eighteen modules were used in the design, and power combining was accomplished with a proprietary passive component called a combiner plate

Influence of Mold Flux Crystallite Film Fracture on Thermal Fluctuations in a Thin Slab Funnel Mold

Mold thermal data from two thin slab casters was investigated. Both facilities employ funnel molds that were instrumented with thermocouple arrays that extend into the lower part of the mold. Under specific operating conditions, regular saw-tooth-like temperature fluctuations were observed in the lower part of the funnel area at both facilities. Flux film sampling and analysis of the mold temperature data suggest that the fluctuations are caused by the fracture, removal and regrowth of the mold flux crystalline layer in the convergent area of the funnel. The effects of the film fracture on the heat flux profile in the mold are examined