| 摘要 |
PURPOSE:To make easy the variable modulation index, by branching the carrier into two waves different in the phase by 180 deg. and changing the impedance of either one wave of the synthesizing circuit by means of the base band signal in the combination of the circuit synthesizing it. CONSTITUTION:The input signal from the carrier input terminal 10 is divided into two waves opposite in phase at the signal branch circuit 1. Taking the voltage between the branch output terminals A and B as 2Va, the voltage between A and B is the value dividing the voltage with the impedance ratio of the varactor diode 2 and the capacitor 3 and the output voltage Vo is outputted to the carrier input terminal 12. Next, with the DC bias of the varactor diode 2 suitably adjusted, when the base band signal is inputted from the input terminal 11, the impedance ratio is changed resulting in obtaining the AM modulation wave Vo. By changing the DC bias is changed with the bias adjuster 4, the modulation index can easily be changed. |
