| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To optimize an output dynamic range by improving distortions of signals when input by a large amount. <P>SOLUTION: A first transistor Q1 and a second transistor Q2 for receiving as input a first signal and a second signal having a phase difference of 180°, and a third transistor Q3 and a fourth transistor Q4, are provided. A base of the third transistor Q3 and the fourth transistor Q4 is connected to a bias circuit 10 via a first resistor R1 and a second resistor R2 for high frequency separation, and to a second input terminal IN2 via a first capacitor C1 and a second capacitor C2. According to this, the third transistor Q3 and the fourth transistor Q4 are separated in terms of AC, and the base of the two is given a negative phase signal, so that a constant current source operation and an amplification operation are both performed. As a result, an amplitude of a maximum output becomes large. <P>COPYRIGHT: (C)2004,JPO</p> |
