NOTCH FILTER DEVICE FOR LORAN C RECEIVER

摘要

PURPOSE:To eliminate a plurality of interference waves, by using a demultiplexer and keeping an optimum state of a lot of notch filters with one D/A converter. CONSTITUTION:Notch filter 2-4 are connected in series and interference waves included in the filters 2-4 are selected at a tuning circuit 12 and detected at a detection circuit 15. A digital voltage is supplied to a D/A converter 19 from a processor 17 and the converter 19 selectively supplies a DC voltage to the filters 2-4 through a demultiplexer 18. Further, the converter 19 and the demultiplexer 18 are controlled with the device 17 including a microcomputer so that the frequency of a wave eliminated interference is made coincident with the frequency of the interference wave at a selected notch filter.