| 摘要 |
<p>A filter comprising an input (1) and an output (2) converters of pin type. Each converter contains two rows (3, 4 and 15, 16) of electrodes (5, 6; 7, 8; and 17, 18; 19, 20) placed on a piezoelectric sublayer (9). The distances (b; b2; b1; b3) between the longitudinal axes of adjacent electrodes (5, 6; 7, 8; 19, 20 and 17, 18) of two groups of all rows (3, 4; 16 and 15) with overlapping sections of electrodes of both permanent (1, 13) and variable (11, 12) length are chosen on a condition of at least partial overlapping of the frequency band of the surface acoustic waves excitated with electrodes (5, 6; 7, 8; 19, 20 and 17, 18) of those rows with a preset frequency pass band of the filter. The row (16) of the electrodes (19 and 20) with their overlapping sections of permanent length (13) is placed on the propagation path (26) of the surface acoustic waves excitated with the row (4) of the electrodes (7 and 8) with overlapping sections of variable length (11). The row (15) of the electrodes (17 and 18) with overlapping sections of variable length (12) is placed on the propagation path (27) of the surface acoustic waves excitated with the row (3) of the electrodes (5 and 6) with overlapping sections of permanent length (1). </p> |
