| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that the optimum FM detection output signal cannot be selected and outputted because an instantaneous change in noise cannot be dealt with. SOLUTION: An FM diversity receiving apparatus has first and second reception systems 10A, 10B for receiving an arriving broadcast radio wave to obtain an FM detection output signal, first and second noise detection circuits 20A, 20B arranged in each of reception systems and detecting first and second noise voltages, a comparing circuit 30 for comparing the first noise voltage with the second noise voltage which are respectively detected, an output switching circuit 40 for selecting and outputting the optimum FM detection output signal on the basis of the result of comparison. The respective circuits 20A, 20B have first and second HPF sections 21A, 21B for extracting noise components from the FM detection output signal, first and second logarithmic amplification detecting sections 22A, 22B for first and second detection output voltages by applying logarithmic amplification detection to the noise components, and first and second LPF sections 23A, 23B for smoothing the first and second detection output voltages to generate first and second noise voltages. COPYRIGHT: (C)2004,JPO
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