| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a frequency synthesizer with which the oscillation frequency of an output signal can satisfy the characteristics as a local oscillation frequency even if the number of crystal oscillators is reduced to one and which can cope with the reception sensitivity suppression, and a communication device. <P>SOLUTION: The frequency synthesizer is provided with a frequency synthesizer part 105 which can shift the oscillation frequency by receiving a frequency switching signal FSW and has a temperature compensation type crystal oscillator (TCXO) 1051 for generating a reference oscillation signal Sref having a reference frequency; and a control part 107 in which the reference oscillation signal Sref outputted by the TCXO 1051 is supplied as an operation clock, the oscillation frequency is shifted by outputting the frequency switching signal FSW to the TCXO 1051 corresponding to the judgement result of whether the sensitivity suppression occurs or not, and which resets setting data of the frequency synthesizer part 105 in order to correct the deviation of the frequency of the local oscillation signal with the output of the frequency switching signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
