| 摘要 |
PURPOSE:To compress the width of a main beam and improve bearing resolution by multiplying the reception signals of the element vibrators in the positions symmetrical to the central axis of an array type transducer then combining and adding their lower frequency components. CONSTITUTION:The outputs of preamplifiers 51-52m corresponding to the pairs of the signals received by the element vibrators (41 and 42m, 42 and 42m-1, -, 4m and 4m+1) in the positions symmetrical to the central axis A' of an array type transducer 4 are multipled respectively by the arrays 81-8m of m pieces of multipliers. The product signals thereof are passed respectively through low-pass filers 91-9m, and are matched of phases by, for example, delay circuits 101-10m, after which they are combined by an adder 7 and are outputted. Thereby, the width of a main beam is compressed and side lobes are supressed as well, so that the bearing resolution during ultrasonic wave searching is improved, and the position, shape, and size of a reflecting body are measured precisely. |
