| 摘要 |
PURPOSE:To obtain a desired characteristic even if an electrode pattern is set in accordance with an impulse response, by providing a common electrode along an envelope of an interdigital electrode, and constituting the interdigital electrode having an odd component on its one side or both its sides. CONSTITUTION:An interdigital electrode 21 is constituted of the first and the second interdigital electrodes 23, 24, and as for the first electrode 23, cross width weighting is performed in accordance with an impulse response for prescribing an even component, and one 23b of two common electrode parts 23a, 23b is formed so as to nearly run along a weighting envelope. The second electrode 24 is formed in the outside of the common electrode part 23b of the first electrode 23, namely, a non-cross area, and on the propagating path of the first electrode 23 or an area containing a little protruded range, an electrode finger is projected from the common electrode part 23b of the first electrode 23, and another common electrode part 24a formed in the vicinity of the part of the maximum cross width of the first electrode 23, and cross width weighting is performed in accordance with an impulse response for prescribing an odd component. |
