| 摘要 |
PROBLEM TO BE SOLVED: To reliably avoid the degradation of the modulation accuracy (EVM) of a transmission signal when the transmission signal or the harmonic wave thereof sneaks into a transmission modulator, concerning a mobile phone terminal.SOLUTION: The mobile phone terminal has: an AD converter for monitoring VCO control voltage that controls VCO in a PLL synthesizer 61; a phase shifter 66 that can change the phase amount of an output signal of the transmission modulator into another phase amount; and a processing unit connected to the AD converter, wherein the processing unit determines, when the variation of the VCO control voltage exceeds an allowable variation, that transmission EVM degradation due to the sneaking of the transmission signal or the harmonic wave of the transmission signal to the VCO occurs, and makes the phase shifter 66 change the phase amount of the output signal of the transmission modulator into the another phase amount to thereby shift a phase relationship between the transmission signal or the harmonic wave of the transmission signal and an output signal of the VCO. |
