| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a radio transmitting unit which is capable of transmitting signals of high quality by regulating a variation in the timing of IQ signals outputted from a digital modulating unit, and eliminating their distortion. <P>SOLUTION: The digital modulating unit 21 subjects the inputted base band signals to band width limitation, upsampling for desired sampling frequencies, and digital orthogonal modulation for each carrier frequency so as to perform multi-carrier composition. A D/A converter 22 converts signals digitally modulated by the digital modulating unit 21 to analog signals. An IQ timing adjusting unit 23 adjusts inter-IQ timing, for instance, by making the lead wires of I phase or Q phase longer in length to output signals of the D/A converter 22. An analog orthogonal modulator 24 up-converts the signals adjusted by the IQ timing adjusting unit 23 to a target RF frequency band and outputs the modulated wave signals of RF band. The modulated wave signals are amplified through a power amplifier 25 and transmitted outside through an antenna. <P>COPYRIGHT: (C)2008,JPO&INPIT |
