| 摘要 |
PROBLEM TO BE SOLVED: To eliminate an expensive local oscillation frequency generator, to suppress frequency interference and to improve performance at reduced cast by using an integer multiple of carrier frequency for quadrature modulation as a frequency signal for up-conversion. SOLUTION: When a 1st data I and a 2nd data Q are respectively inputted to mixers 221 and 225 inside a quadrature modulation part(QM) 2, these data are modulated by the mixers 221 and 225 and transmitted to a synthesizer 227. At the synthesizer 227, these two modulated signals are synthesized and a QM signal is outputted. The frequency of this QM signal is increased to a communication frequency band by a mixer 241 after a required frequency band is filtered through a band filter 229. Namely, the mixer 241 performs up-conversion with a frequency signal fc for up-conversion. In this case, the frequency signal fc can be provided by making a carrier frequency signal fm into an integer multiple through a multiplier 235, then filtering that signal through a band filter 237 and amplifying it through an amplifier 239. |
