| 摘要 |
PURPOSE:To improve the cross modulation, by branching a part of an input signal of a main amplifier, applying it to a subamplifier with greater nonlinear distortion, and after delaying the phase by 180 deg., adjusting the level of the output and synthesizing it with the output of the main amplifier. CONSTITUTION:An input signal from a signal input terminal is applied to a main amlifier 3, a part of it is picked up at a directional coupler 2 and applied to a subamplifier 4. In the subamplifier 4, the saturated output is smaller than that of the main amplifier 3 and the gain is almost the same, so that the absolute level of the cross modulation component can be greater. The output of the subamplifier 4 is matched to a suitable level by a variable attenuator 5 and the phase is delayed by 180 deg. by a variable phase shifter 6, it is applied to a directional coupler 2' and synthesized with the output of the main amplifier 3. |
