Title:
FILTER
Document Type and Number:
Japanese Patent JP2944063
Kind Code:
B2
Abstract:
PURPOSE: To make an output signal level constant even when a frequency of an input signal changes.
CONSTITUTION: An input signal whose level depends on its frequency is fed to an amplifier section 26 via an amplifier section 22 and a variable attenuation section 24a. An output signal from the amplifier section 26 is fed to any of band pass filters 32, 34, 36, 38 selected by a switch circuit 112 and then given to an output terminal 48. The attenuation of the variable attenuation section 24a is changed through the adjustment of variable resistors 88, 90, 92, 94, and any of variable resistors 88, 90, 92, 94 connecting in series with any conductive transistor(TR) of switching TRs 96, 98, 100, 102 is operated. The TRs 96, 98, 100, 102 correspond to the filters 32, 34, 36, 38 and when the filter 32 is selected, the TR 96 is conductive, The resistance of the variable resistors 80, 90, 92, 94 is selected so that the signal level at the output terminal 48 is almost a predetermined level when any filter is selected.
Inventors:
AKISADA MAKOTO
Application Number:
JP24752093A
Publication Date:
August 30, 1999
Filing Date:
September 07, 1993
Export Citation:
Assignee:
DEIETSUKUSU ANTENA KK
International Classes:
H03G3/20; H03H11/04; H03H11/34; H04B1/18; H04N5/40; (IPC1-7): H03H11/34; H03G3/20; H03H11/04; H04N5/40
Domestic Patent References:
| JP4326282A | ||||
| JP61141266A |
Attorney, Agent or Firm:
Hiroshi Tanaka (2 outside)
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