FRONT END FOR RADIO FREQUENCY TUNER, AND TUNER

摘要

PROBLEM TO BE SOLVED: To provide a front end for a radio frequency tuner for connection to a cable distribution network. SOLUTION: An input is connected to a signal path equipped with an LNA 9 connected to a signal splitter 11 via an AGC stage 10. An input path has a sufficiently wide bandwidth for passing all channels in an input signal and has a substantially constant voltage standing wave ratio over the bandwidth. The splitter 11 supplies individual signals to a plurality of filtering paths and the respective filtering paths are provided with fixed filters 12 and 13. The plurality of paths are selectable at a prescribed time, and the filters 12 and 13 divide an input frequency band into a plurality of adjacent or a little overlapped sub-bands. The output of the relevant font end is supplied to a double conversion device equipped with up converters 2 and 3, down converters 5 and 6 and first and second IF filters 4 and 7, for example. COPYRIGHT: (C)2003,JPO