| 摘要 |
PURPOSE:To miniaturize a surface acoustic wave device, by providing a coded parallel stripe form electrode and another same form electrode having specific weighting on the same substrate as transmitting and receiving surface acoustic wave converters respectively. CONSTITUTION:A receiving parallel stripe form electrode 3 synthesizes the MSK- modulated codes, and consists of many tapped electrodes with spances L secured among them. This space L is set equal to L=V.T, i.e., the product of the surface wave speed V and the information symbol length T. In such a constitution of the electrode 3, it is possible to receive a signal having 2T (=2L/V) pulse width and produced from a transmitting roller screen type electrode 2 in the form of a sum series of signals having a time difference T=L/V from each other. Then the polarity of the tapped electrode is selected by a desired code series or its differential series. Thus an MSK-modulated code signal series can be obtained. |
