Receiver in a radio communication system

摘要

A receiver has a low spurious level and a high frequency precision without increasing power consumption of a local oscillator. The receiver comprises first and second local oscillators; a phase locked loop operating based on an output of the first local oscillator; a first mixer for receiving an RF signal or an IF signal, and converting the received signal to a second IF signal according to an output signal of the phase locked loop; an analog-to-digital converter for converting an output signal of the first mixer to a digital signal; a second mixer for converting the digital signal to a detection process frequency according to an output of the second local oscillator; and a filter for bandpass filtering, interposed between the first mixer and the analog-to-digital converter or between the analog-to-digital converter and the second mixer.