Abstract
This paper describes a method of designing a multi-beam transducer capable of simultaneous detection in six fixed directions around a transducer and in the direction perpendicular to its radiation surface, using a total of seven beams. Beams in multiple directions around the transducer are realized by appropriate modifications to arrange the positions of the transducer elements and wiring of the elements inside the transducer. Compared to the normal phased array in which each element is connected to electric circuits with a signal line, this method ensures a substantial reduction in the number of signal lines, as it uses 14 lines regardless of the total number of elements. Therefore, it also offers a great simplification in the scale of the beam forming circuit in both the transmitting and receiving modes. We made an experimental model of the seven-beam transducer to verify the validity of the method and measured the basic acoustic characteristics. As a result, we confirmed the desired performance. Studies also were made to determine a method of realizing a transducer with more than seven beams.
