Direct RF modulation transmitter, sampling clock frequency setting method for direct RF modulation transmitter

PROBLEM TO BE SOLVED: To provide a direct RF modulation transmitter capable of satisfying a radiation level regulation even without providing a SAW filter. SOLUTION: A direct RF modulation transmitter includes: digital/RF converters 105, 106 to which an I digital baseband signal, a Q digital baseband signal, and a differential local signal are inputted, for modulating the differential local signal with the I digital baseband signal and the Q digital baseband signal; a PLL circuit 102 for generating a sampling clock signal fs which determines data rates of the I digital baseband signal and the Q digital baseband signal at the digital/RF converters 105, 106; and a sampling clock frequency setting circuit 101 for determining the frequency of the sampling clock signal fs generated by the PLL circuit 102, according to an intended transmission carrier frequency. ;COPYRIGHT: (C)2013,JPO&INPITPROBLEM TO BE SOLVED: To provide a direct RF modulation transmitter capable of satisfying a radiation level regulation even without providing a SAW filter.SOLUTION: A direct RF modulation transmitter includes: digital/RF converters 105, 106 to which an I digital baseband signal, a Q digital baseband signal, and a differential local signal are inputted, for modulating the differential local signal with the I digital baseband signal and the Q digital baseband signal; a PLL circuit 102 for generating a sampling clock signal fs which determines data rates of the I digital baseband signal and the Q digital baseband signal at the digital/RF converters 105, 106; and a sampling clock frequency setting circuit 101 for determining the frequency of the sampling clock signal fs generated by the PLL circuit 102, according to an intended transmission carrier frequency.