Patent ID: 7250895

Claim:
A radio receiver comprising: an antenna to receive a radio wave and output a RF received signal; an orthogonal demodulator to demodulate the RF received signal into a first baseband signal and a second baseband signal orthogonal to each other using a first local signal and a second local signal orthogonal to each other; and a multiple input AD conversion apparatus comprising: a first unit AD converter including a plurality of first conversion stages connected in cascade to convert the first baseband signal into a first digital output signal; a first sample-and-hold circuit followed by the first unit AD converter to sample and hold the first baseband signal and supply the first baseband signal to the first unit AD converter; a second unit AD converter including a plurality of second conversion stages connected in cascade to convert the second baseband signal into a second digital output signal; a second sample-and-hold circuit followed by the second unit AD converter to sample and hold the second baseband signal and supply the second baseband signal to the second unit AD converter; and a plurality of operational amplifiers each configured to be shared between a corresponding first conversion stage of the first conversion stages and a corresponding second conversion stage of the second conversion stages in a time sharing.