| Budget Amount *help |
¥1,940,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥240,000)
Fiscal Year 2007: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
Recently, differential circuits are adopted widely in the RF (Radio Frequency) circuits of mobile telecommunications systems such as cellular phones, because they are superior to conventional non-differential circuits in both the noise-resistant and the power consumption. The balanced acoustic wave device is a kind of the acoustic wave device that has several balance-terminals and works effectively in differential circuits. However, in the design of the balanced acoustic wave devices, the balance characteristics of the signals of their balance-terminals have to be considered. Therefore, conventional optimum design methods of non-balanced acoustic wave devices cannot be used directly to the design of balanced acoustic wave devices.
In this research, a new optimum design method of balanced acoustic wave devices based on the balance analysis has been developed. First of all, three core techniques of the optimum design method, namely, simulation technique, evaluation technique and optimization technique, were proposed respectively. Also the effectiveness of those techniques was confirmed.
Next, the design of a balanced surface acoustic wave filter, which is a typical balanced acoustic wave device, was formulated as a multi-objective optimization problem. Then a genetic algorithm (GA) and an original genetic local search (GLS) were applied to the multi-objective optimization problem respectively to obtain a set of Pareto-optimum solutions.
Finally, by analyzing the set of Pareto-optimum solutions, it was found that two or more different functions of the balanced acoustic wave device could be improved simultaneously by increasing the number of the design parameters considered in the optimum design.
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