To obtain a filtering system which attenuates interference wave of wide band included in an input signal and a plurality of adjoining interference waves.
The filtering system comprises a prestage integration means (a voltage/current converter (21), a capacitor (22)) for charging the capacitor (22) with a current obtained from an input voltage signal, a post-stage integration means (a switch (24), a switch (25), a capacitor (26)) for charging the capacitor (26) with a noninversion current obtained from the output signal of the prestage integration means or a current (inversion current) having an inverted sign, a switch (27) for outputting a voltage signal produced when the post-stage integration means charges the capacitor (26) as a discrete signal after filtering, and a control unit (8) for controlling the post-stage integration means such that no integration processing is executed for a fixed period between the integration processing by a noninverted current and the integration processing by an inverted current.
COPYRIGHT: (C)2007,JPO&INPIT
HAYASHI RYOJI
TAJIMA KENICHI
