| 摘要 |
PURPOSE:To reduce the number of parts such as a coil, a condenser and the like and to improve the utilization factor of a pass-band by using a band pass wave filter type delay line to which a band pass type unit circuit obtained by reactance-converting a constant K or derived m-type low-pass type unit circuit is longitudinally connected. CONSTITUTION:A BP filter in which a coil l0 is converted to a serial circuit of a coil l1 and a condenser C2 and a condenser C0 is converted to a parallel circuit of a condenser C2 and a coil l2 is used to form a delay line. In DL to which a unit circuit of BP filter formed by reactance-converting a constant K-type LP filter is longitudinally connected, k type unit circuit is constructed so that a portion A is substantially one stage of net by connection. In case of derived m-type unit circuit, a portion B is one stage of net. Accordingly, the number of condensers is two or three, and the number of coils is two or three. Thus, the number of parts, especially coils in a delay line can be reduced while the merits of RF system SONAR is kept. Also in IF system, the number of parts can be reduced. |
