Satellite antennas

Microwaves broadcast from the SPS would be received with about 85% efficiency. A conventional microwave antenna is even better, but the cost and complexity are much greater. Rectennas would be several kilometers across and crops and farm animals could be raised under the rectenna, since the thin wires used only slightly reduce sunlight. For best efficiency the satellite antenna would be between 1 and 1.5 kilometers in diameter and the ground rectenna around 14 kilometers by 10 kilometers. This would allow the transfer of 5 to 10 gigawatts of power. 

Jet engine cones, hydraulic fluid tanks for j et engines, stiffeners of acoustic panels, spacers for engine acoustic panels, protection hoods, empennages, supports for satellite antennas. 

By applying a highly hydrophobic film to the surface, snow was reported to be less likely to adhere to the surface due to the large amount of air between the surface and snow. A satellite antenna covered with a highly hydrophobic film, reduced the disruption of communication by the adherence of snow to the antenna [78,82], Besides, these results portended well for techniques to apply highly hydrophobic film coatings to traffic lights, billboards, and roofs in areas with heavy snowfall. 

Bourret, R, GoodaU, S., and Samuelides, M. (1989), Optimal Scheduling by Competitive Activation Application to the Satellite-Antennae Scheduling Problem, in Proceedings of the International Joint Conference on Neural Networks. 

Satellite Communications and GPS. Satellite communications developed in both the United States and Russia shortly after the launch of Sputnik in 1957. Most satelhte transmissions are in the micro-wave bands, but some use other electromagnetic wavelengths as well. There are a variety of devices for satellite transmissions, but many of them use an enhanced vacuum tube technology with names such as magnetron and gyrotron. Elarly satellite antennae were very large but have been greatly reduced in size. 

FIGURE 10.242 Addition of a lightning rod to a satellite antenna ground system. (After [9].)... 

The main object of this paper is to analyze the reliability of the complex mechanical system on the base of the Lambda-Tau (L-T) methodology and fuzzy math. In order to quantify the uncertain of the system reliability more close, this paper utilizes the improved artificial bee colony algorithm to optimize the L-T methodology. The obstacle of the complex structure will be conquered with the help of the petri nets approach. An example of a satellite antenna drive system is taken account to demonstrate this method. The system reliability model of the drive system is built by the petri net and the reliability behavior is analyzed with the lABCBLT proposed in this paper. At last, the results obtained from GABLT, PSOBLT and traditional ABCBLT are compared and it can be conducted that that the method proposed by this paper could get more precise results in uncertain mathematic. 

THE EXAMPLE OF THE DRIVE MECHANICAL SYSTEM OE THE SATELLITE ANTENNA... 

A two-axis-position mechanism of satellite anteima (shown as Fig. 1) is a typical spatial mechanism as a key component that performs two degrees of freedom movement to realize the accurate positioning, posture alignment and tracking of the satellite antenna. The reliability of this mechanism correlates with mission success (Huibo Zhang 2012). It mainly consists of rack, longitudinal shaft and cross shaft. The longitudinal shaft... 

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