| 摘要 |
PURPOSE:To provide a small-sized orthogonal modulator by simplifying an addition circuit for the transmission of a non-modulation carrier wave signal by providing two selection circuits for alternatively selecting two variable DC voltage generation circuit, a DC voltage signal and a base band signal. CONSTITUTION:When a non-modulation carrier wave is outputted, the output signal of a balanced mixer 7 is outputted as it is via an adder 11 and a non- modulation carrier wave of a constant amplitude is obtained since the output voltage of a balanced mixer 8 also becomes 0 when both of switches 5, 6 are switched to a DC voltage side b, the output of a variable DC voltage generator 1 is defined as the constant amplitude and the output voltage of the other variable DC voltage generator 3 is set to 0. When a modulation wave is outputted, the modulation wave can be outputted in the same way as in conventional orthogonal modulator by setting the both of the switches 5, 6 to a base band signal side a. |
