| 摘要 |
PURPOSE:To control an amplifying circuit with one control signal, by connecting both the ends of a PIN diodes in series connection to a constant voltage source and applying a control signal to the center. CONSTITUTION:PIN diodes RC1, RC2 are in series connection via resistors R3, R4, and both the ends are connected to constant voltage sources E1, E2. The impedance of the diodes RC1, RC2 is changed complementarily with the amplitude of a control signal VC from an amplifier IC2 applied to the connecting point of the resistors R3, R4. Thus, the gain of an amplifying transistor TR1 can be changed. |
