Patent ID: 8619997

Claim:
A receiving apparatus comprising: a local oscillator configured to output first and second local oscillator signals whose phases are orthogonal to each other; a mixer configured to mix a received signal with the first local oscillator signal and output a first intermediate frequency signal, and to mix a received signal with the second local oscillator signal and output a second intermediate frequency signal, the first and second intermediate frequency signals having a predetermined intermediate frequency; a first filter configured to allow a component from a desired signal to be received to pass therethrough, and eliminate a component from an image signal having a frequency symmetrical with a frequency of the desired signal with respect to a frequency of the first and second local oscillator signals, in the first and second intermediate frequency signals; a second filter configured to allow a component from the image signal to pass therethrough, and eliminate a component from the desired signal, in the first and second intermediate frequency signals; a comparator configured to compare levels between output signals of the first and second filters; and a control unit configured to switch the frequency of the first and second local oscillator signals to a difference frequency between the frequency of the desired signal and the intermediate frequency or to a sum frequency of the frequency of the desired signal and the intermediate frequency, according to a comparison result of the comparator.