Patent ID: 7672654
Filing Date: 2010-03-02
Classification: H03G,H04B,H04H,H04N

Abstract:
1. A broadcasting receiver comprising: a radio-frequency signal receiving unit for receiving a broadcasting radio-frequency signal; an amplifying unit having a feed back terminal, for amplifying the radio-frequency signal received by the radio-frequency signal receiving unit at a gain corresponding to a feed back signal entered to the feed back terminal; a mixing unit for mixing the radio-frequency signal amplified by the amplifying unit with a variable oscillation signal corresponding to a channel selection signal for selecting a frequency band to be received whereby the mixing unit generates a low frequency signal; a signal generating unit for generating a first signal having an amplitude corresponding to the low frequency signal generated by the mixing unit; a signal processing unit for executing a filtering process on the low frequency signal generated by the mixing unit to allow only signal components of the low frequency signal which fall within a filtering frequency band to pass through, the filtering frequency band being determined by a relationship between a frequency band to which the low frequency signal belongs and a frequency band assigned to a broadcast receiving area where the broadcasting receiver receives the broadcasting radio-frequency signal; a subtracting unit for calculate a difference between the first signal generated by the signal generating unit and the signal subjected to the filtering process by the signal processing unit and for generating a second signal corresponding to the calculated difference; and a first signal selection unit for feeding back the second signal as a negative feed back signal to the feed back terminal of the amplifying unit, when an amplitude of the second signal generated by the subtracting unit is larger than a predetermined value, and feeding back the first signal as a negative feed back signal to the feed back terminal of the amplifying unit, when the amplitude of the second signal generated by the subtracting unit is not larger than the predetermined value.