| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an FSK wireless transmitter 10 for qualifying the frequency of a transmission wave corresponding to each logical value independently of a DC offset of FSK modulation data applied to a voltage controlled oscillator 136. <P>SOLUTION: An A/D converter 15 applies A/D conversion to a voltage of the FSK modulation data and gives the result to a CPU 14. Let the instruction frequency of the transmission wave of a selected channel be f<SB>o</SB>, the frequencies of the transmission wave generated on the upper side and the lower side in the frequency-axis direction, corresponding to each logical value of the FSK modulation data, be respectively f<SB>u</SB>, f<SB>l</SB>, and the center point frequency of the frequencies f<SB>u</SB>, f<SB>l</SB>be the center point frequency f<SB>m</SB>. The CPU 14 adjusts the setting data of DDS 12, on the basis of the detected DC offset to control the output frequency of the DDS 12. The output frequency of the DDS 12 is controlled such that the center point frequency f<SB>m</SB>becomes the frequency f<SB>o</SB>. <P>COPYRIGHT: (C)2007,JPO&INPIT |
