| 摘要 |
The invention relates to a resonator filter cascade on the basis of acoustic surface waves, for which at least two transversely coupled resonator filters, which are composed of several resonator structures disposed adjacent to one another and form a wave guide for acoustic surface waves, and switching transducers are present. It is an object of the invention to change resonator filter cascades of the known type so that the insertion attenuation of the filters is reduced by decreasing the attenuation as a result of cascading, without using a switching coil. This objective is accomplished by a resonator filter cascade, for which the number of resonator structures (21; 23; 31; 33), the transducers of which are switching transducers (211; 231; 311; 331), is more than one in all transversely coupled resonator filters (2; 3) and the switching transducers, belonging to one and the same transversely coupled resonator filters (2; 3), are not connected with one another. In addition and pursuant to the invention, two switching transducers (211; 311 and 231; 331) of different transversely coupled resonator filters (2; 3) are each connected with one another over a pair of electrically conducting connections. The invention can be used, for example, in the case of band pass filters with a relative band width of the order of 0.1% as well as for oscillators.
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