| 摘要 |
<p>18 "PARALLEL-SERIES ACOUSTIC WAVE DEVICE ARRANGEMENT" N2 acoustic wave devices (A,B,S,T; where N is an integer greater than unity) with substantially the same electrical impedance and transfer characteristics are electrically connected in a parallel-series arrangement which has substantially the same electrical impedance and transfer characteristics as anyone of the individual N2 devices, but an increased active device area. The increased active area reduces stress and alleviates acoustically-induced migration in the metal of, for example, transducer electrode fingers (6,7) of resonators at high power levels. The parallel-series arrangement consists of N groups each of which comprises N devices (A,B or S,T) the corresponding pairs of terminals (4,54 and 54,55) of which are connected in series. Some terminals (54 or 55) may be common to two or more devices and some devices may have merged transducers in which the electrode fingers (6 or 7) of one transducer are a longitudinal extension of the fingers of a parallel transducer. In the case of multi-port devices the input and output terminal pairs may be differently grouped, as regards the individual devices to which they belong. (Figure 5)</p> |
