| 摘要 |
A distributed-transducer surface wave device for signal processing of the type which comprises a crystal substrate upon which is disposed at least one transducer set, including an input transducer adapted for connection to an input electrical signal and an output transducer, each transducer including at least a pair of interdigitated electrodes, the application of an electrical signal to the input transducer causing surface wave propagation on the surface of the crystal substrate, the electrodes of the transducers being aligned in a direction perpendicular to the direction of wave propagation, wherein the interdigitations of the electrodes are generally coded, for example, according to a Barker code. The surface wave device further comprises a logic decision circuit having three input connections: (1) a first input connected to the output transducer; (2) a second adapted for connection to a clock sync source; and (3) a third adapted for connection to a source of binary signals; the output of the logic decision circuit being connected to the input transducer. A function of the logic devision circuit is to enable an incoming pulse from the binary signal source, if present, to be transmitted to the input transducer, otherwise to enable pulses from the output transducer to be circulated through the transducer set, all pulses being clocked by signals from the clock sync source. One of the main functions of the acoustic wave devices of this invention is to serve as a delay line for the propagating surface wave.
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