| 摘要 |
PROBLEM TO BE SOLVED: To prevent damage to other circuits from leakage output signals from other power amplifiers when one power amplifier is dismounted or mounted during operation.SOLUTION: According to an embodiment, a digital amplitude modulation device power-amplifies a predetermined signal in a plurality of power amplifiers arranged in parallel so as to be controlled on/off in response to a voltage amplitude level of a signal to be modulated, and combines outputs of the respective power amplifiers in a combiner comprising primary windings of transformers connected to the respective power amplifiers and secondary windings of the transformers opposed to the primary windings, to generate an amplitude-modulated wave. The plurality of power amplifiers each include first switching means and second switching means. The first switching means switches between supply and interruption of power. The second switching means switches the primary winding of the transformer for the power amplifier switched between supply and interruption of power to a normally open state or a short circuit state, and switches to supply or interruption of an on/off control signal. |
