| 摘要 |
An IC in a front end circuit applicable to various types of television broadcast system. Tuning circuits (12A-12C, 14A-14C) and high frequency amplifiers (13A-13C) corresponding to a plurality of reception bands of television broadcast are provided. A switch circuit (11) for supplying a received signal to the tuning circuits (12A-12C) selectively, and a switch circuit (15) for taking out the outputs from the tuning circuits (14A-14C) selectively are provided. Mixer circuits (21I, 21Q) to which the output from the switch circuit (15) is supplied, and a PLL (30) for supplying local oscillation signals (SLOI, SLOQ) having phases intersecting perpendicularly those of the mixer circuits (21I, 21Q) are also provided. Furthermore, a complex band-pass filter (24) receiving the outputs from the mixer circuits (21I, 21Q), and a circuit (25) for outputting an intermediate frequency signal SIF by operating the output from the complex band-pass filter (24) are provided. ® KIPO & WIPO 2009 |
