| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an I/Q modulator unit capable of keeping an RF output signal level fixed at all times. <P>SOLUTION: An I/Q modulator unit 30 up-converts digitally modulated I signals and Q signals of a base band having a 90° phase difference to RF signals of a GHz band through a modulation circuit 2 and outputs them through a power amplifier 2. The level of the RF signals outputted from the power amplifier 2 is detected in a level detector 10 and a gain of a gain variable amplifier 4 provided between the modulation circuit 5 and the power amplifier 2 is controlled by the detected output. <P>COPYRIGHT: (C)2003,JPO |
