| 摘要 |
<p>In order to suppress the deterioration in a characteristic of an output signal from an amplification circuit, this amplification circuit is provided with: an amplification means which amplifies an input signal and outputs the amplified signal from an output terminal as an output signal, and which has a variable gain; and a control means which is provided with a detection means and controls the gain of the amplification means so that the amplitude of the output signal detected by the detection means becomes a predetermined value, said detection means detecting the power of the output signal at a detection point at which one end of a first impedance element and one end of a second impedance element are connected, the first impedance element having the other end connected to a power source which supplies current to the amplification means and having an impedance value to the alternating current equal to or larger than the impedance value to the direct current, and the second impedance element having the other end connected to the output terminal and having an impedance value to the alternating current equal to or larger than the impedance value to the direct current.</p> |
