| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an ASK modulation amplifier circuit capable of improving the linearity of modulation depth when a level of a modulation signal is low and capable of obtaining an output signal with large amplitude.SOLUTION: A high-frequency signal and a modulation signal are supplied to a first amplifier, and amplification and ASK modulation of the high-frequency signal are performed. The first amplifier is set to have a bias that does not output a modulation output signal by a first control block in a state that the modulation signal is not supplied. An output signal of the first amplifier and the modulation signal are supplied to the second amplifier. The amplification factor of the second amplifier is set to be higher than the amplification factor of the first amplifier by a second control block.</p> |
