Patent ID: 7974363
Filing Date: 2011-07-05
Classification: H04B

Abstract:
1. A receiver supporting a plurality of radio communication systems having different specifications, the receiver comprising: setting means that sets a value suitable for a carrier frequency used in one radio communication system selected from among the radio communication systems; a clock generation circuit that generates a first clock having a first frequency which is substantially the same as the carrier frequency and a second clock having a second frequency obtained by dividing the first frequency by the value set by the setting means; a voltage-current conversion amplifier that converts a received voltage signal corresponding to a signal received through an antenna into a current signal; a switch that switches between connection and disconnection modes in accordance with the first clock to output the current signal supplied from the voltage-current conversion amplifier; integrators that operate in accordance with the second clock, each integrator receiving as input signals a predetermined analog value and the result of operation obtained by the preceding integrator based on the current signal supplied from the switch, each integrator including two or more switched capacitor circuits and an operational amplifier connected to the switched capacitor circuits; an AD conversion circuit that converts a signal supplied from the preceding integrator into a digital value at each of the leading and trailing edges of the second clock; and a feedback circuit that operates in accordance with the second clock and feeds a value corresponding to the digital value obtained by conversion through the AD conversion circuit as the predetermined analog value back to each of the integrators.