Patent ID: 7305219

Claim:
A portable radio terminal for realizing automatic frequency control (AFC) for automatically controlling an oscillation frequency of an oscillator, comprising: means for detecting whether a frequency shift value in a received signal is greater than a frequency shift threshold; means for setting, if the frequency shift value in the received signal is greater than or equal to the frequency shift threshold and a current AFC intermittent operation performing period is greater than a minimum threshold period, an AFC intermittent operation performing period to a first value less than the current AFC intermittent operation performing period; and means for setting, if the frequency shift value in the received signal is less than the frequency shift threshold and the current AFC intermittent operation performing period is greater than a maximum threshold period, an AFC intermittent operation performing period to a second value greater than the current AFC intermittent operation performing period, wherein the maximum threshold period is greater than the minimum threshold period.