| 摘要 |
1,002,941. Multi-resonant filters. GENERAL ELECTRIC CO. Ltd. May 20, 1964 [May 20, 1963], No. 19948/63. Heading H3U. A filter network comprises two or more capacitances in series across the input terminals and an equal number of inductances joined in parallel with different numbers of said capacitances, all the inductances being joined at one of their ends to one of the input terminals, the arrangement being parallel resonant to two or more frequencies. Thus in Fig. 6 components 5 and 3 resonate at the first frequency, 6 and 4 at the second frequency and 23 and 24 at the third frequency. A fraction of the output can be taken off from an inductor coupled with the coil 5 and used for neutralization in an amplifier (Fig. 2, not shown). If the output impedance is to be different from the input impedance, either of terminals 1 or 7 can be tapped down the coil 5 (Figs. 3 and 4, not shown). For use as a multipletuned band-pass arrangement, two circuits such as Fig. 6 are used with the corresponding inductances magnetically coupled (Fig. 5, not shown).
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