| 摘要 |
PROBLEM TO BE SOLVED: To make the filter small in size and light in weight by configuring acoustic wave filter elements including a ladder filter forming a grouped resonator along with a propagation major axis on a substrate material in an in-line structure. SOLUTION: An acoustic wave resonator 100 consisting of reflectors 115, 115' and one transducer 105 or over separated from the reflectors 115, 115' by a gap 112 has an arrangement on a plane of these elements in an in-line structure. The transducer 105 and the reflectors 115, 115' are made up of electrodes of 1/4 wavelength or fingers 109, 109', or 116, 116' and has the two electrodes 109, 109' or 116, 116' or a gap for each wavelength. An optimum band width, insertion loss and other characteristics are obtained by adjusting a width 112' of the gap 112 between the transducer 105 and the reflectors 115, 115' to obtain the acoustic filter with small size and light weight. |
