Patent ID: 8463212

Claim:
A receiving apparatus comprising a signal-level detecting unit that detects a signal level of an input signal transmitted through a communication cable; a first signal-level converting unit including plural amplifiers that are provided for respective predetermined signal level areas obtained by dividing a signal level range of the input signal and amplify or attenuate the input signal with a gain for converting input signals in the signal level areas into a fixed level, the first signal-level converting unit capturing the input signal and converting a signal level of the input signal with any one of the plural amplifiers; a switching unit that is provided to correspond to the plural amplifiers and switches an output of a signal, a level of which is converted by the plural amplifiers; a switching control unit that selects a specific amplifier out of the plural amplifiers on the basis of the signal level of the input signal detected by the signal-level detecting unit and controls the switching unit to select an output signal from the selected amplifier; a band-pass filter that allows only a predetermined frequency band in the signal, the output of which is switched by the switching unit, to pass; a second signal-level converting unit that converts a signal level of an output signal from the amplifier into a predetermined signal level; a mixer that mixes the signal having passed through the band-pass filter, the signal level of which is converted by the second signal-level converting unit, and an oscillation signal to generate an intermediate frequency signal; and a demodulating unit that demodulates the intermediate frequency signal generated by the mixer, wherein the predetermined level for the conversion by the second signal-level converting unit is a level of the input signal at which S/N of the mixer is maximized.