Patent ID: 7319850
Filing Date: 2008-01-15
Classification: H03H,H04B

Abstract:
1. A low noise block downconverter converting a received right-hand (or horizontally) polarized wave signal and a received left-hand (or vertically) polarized wave signal to intermediate frequency signals, comprising: a first circuit outputting said received right-hand (or horizontally) polarized wave signal; a second circuit outputting said received left-hand (or vertically) polarized wave signal; a first local oscillator circuit outputting a first local oscillation signal; a second local oscillator circuit outputting a second local oscillation signal; a first mixer circuit mixing the right-hand (or horizontally) polarized wave signal output from said first circuit and the first local oscillation signal from said first local oscillator circuit to output the intermediate frequency signal; a second mixer circuit mixing the left-hand (or vertically) polarized wave signal output from said second circuit and the second local oscillation signal from said second local oscillator circuit to output the intermediate frequency signal; a first filter for removing interference waves from the output of said first mixer circuit; and a second filter for removing interference waves from the output of said second mixer circuit; one of said first and second filters including a plurality of stages of parallel resonant trap circuits, wherein the one of said first and second filters is a low pass filter including said parallel resonant trap circuit and a series resonant trap circuit.