Patent ID: 8208076

Claim:
A front end circuit, comprising: a plurality of series circuits having tuning circuits and high frequency amplifiers individually corresponding to a plurality of reception bands into which television broadcasts are divided; a first switch circuit for selectively supplying a reception signal to the plural series circuits; a second switch circuit for selectively extracting an output of the plural series circuits in an interlocking relationship with said first switch circuit; first and second mixer circuits to which the reception signal output from said second switch circuit is supplied a PLL for supplying first and second local oscillation signals having phases orthogonal to each other to said first and second mixer circuits; a complex band-pass filter to which outputs of said first and second mixer circuits are supplied; and an output circuit for mathematically operating an output of said complex band-pass filter and outputting an intermediate frequency signal, wherein, the foregoing are formed as an integrated circuit, switching among the plural reception bands is carried out by switching of said first and second switch circuits, and the tuning frequency of the tuning circuit in the switched reception band and the frequency of the first and second local oscillation signals to be supplied from said PLL to said first and second mixer circuits are varied to obtain an intermediate frequency signal of an object channel.