Patent ID: 6226499
Filing Date: 2001-05-01
Classification: H04B

Abstract:
A radio circuit apparatus utilized in a time division multiple access system comprising:a local oscillator;a frequency divider;a modulator;a transmitted frequency converter;a first received frequency converter; anda second received frequency converter, wherein:when the radio circuit apparatus is transmitting, an output signal of the local oscillator is inputted to the transmitted frequency converter and is inputted into the frequency divider and then divided into a predetermined dividing number to be a signal of a transmitted intermediate frequency; the modulator modulates the signal of the transmitted intermediate frequency with a modulating signal to be outputted to the transmitted frequency converter; and the transmitted frequency converter converts an output signal of the modulator to a transmitted signal by the output signal of the local oscillator,when the radio circuit apparatus is receiving, an output signal of the local oscillator is inputted into the first received frequency converter; the first received frequency modulator outputs a received signal to the second received frequency converter after converting the received signal into a signal of a first received intermediate frequency by the output signal of the local oscillator; the second received frequency converter converts the signal of the first received intermediate frequency into a signal of the second received intermediate frequency by a signal of a fixed frequency, andoutput frequencies of the local oscillator are switched between when the radio circuit apparatus is transmitting and when the radio circuit apparatus is receiving.