Patent ID: 7460850
Filing Date: 2008-12-02
Classification: H04B,H04W,Y02D

Abstract:
1. A receiving circuit including a local oscillation signal output terminal and a local oscillation signal input terminal, said receiving circuit comprising: a mixer for mixing an inputted high frequency signal with an inputted local oscillation signal by multiplication to convert the high frequency signal into a predetermined frequency-converted signal, and for outputting the frequency-converted signal; a local oscillator for generating a local oscillation signal having a predetermined local oscillation frequency, and for outputting the local oscillation signal; a first switch circuit for switching over between first and second cases, said first switch circuit in the first case outputting the local oscillation signal outputted from the local oscillator to said mixer, and outputting the local oscillation signal through the local oscillation signal output terminal, and said first switch circuit in the second case outputting a local oscillation signal inputted through the local oscillation signal input terminal to said mixer; and a controller for controlling in the first case to turn on power supply to the local oscillator, and controlling the first switch circuit in the first case to output the local oscillation signal outputted from the local oscillator to said mixer, and to output the local oscillation signal through the local oscillation signal output terminal, and for controlling in the second case to turn off power supply to the local oscillator, and controlling the first switch circuit in the second case to output the local oscillation signal inputted through the local oscillation signal input terminal to said mixer.