초록 ▼

A filter circuit largely reducing electric power consumption compared with a conventional one, as well as realizing the initial acquisition in high enough speed. In a filter circuit according to the present invention, a matched filter and a sliding correlator are used in parallel; the first acquisit

A filter circuit largely reducing electric power consumption compared with a conventional one, as well as realizing the initial acquisition in high enough speed. In a filter circuit according to the present invention, a matched filter and a sliding correlator are used in parallel; the first acquisition and holding is executed by a matched filter, a correlating operation is executed by a sliding correlator and a voltage supply to the matched filter is stopped.

대표청구항 ▼

[ What is claimed is:] [1.] A filter circuit comprising:i) a matched filter receiving an input signal;ii) a plurality of sliding correlators, each receiving said input signal;iii) a timing detecting circuit coupled to said matched filter and each of said sliding correlators, said timing detecting ci

[ What is claimed is:] [1.] A filter circuit comprising:i) a matched filter receiving an input signal;ii) a plurality of sliding correlators, each receiving said input signal;iii) a timing detecting circuit coupled to said matched filter and each of said sliding correlators, said timing detecting circuit detecting when an output of said matched filter reaches a predetermined level as many times as a number less than or equal to a number of said sliding correlators;iv) a controller coupled to said timing detecting circuit for setting a basic timing of a multiplication for each of said sliding correlators according to an output of said timing detecting circuit;v) a plurality of time trackers coupled to said controller, each of said time trackers being coupled to one of said sliding correlators and receiving said basic timing given by said controller, each of said time trackers adjusting said basic timing for said multiplication of said sliding correlator according to an output of said sliding correlator; andvi) a first voltage supply switch coupled to said matched filter for stopping operation of said matched filter after completion of said detection by said timing detecting circuit.