Patent ID: 9654065
Date: 2017-05-16
CPC Classifications: H03F

Claim:
1. A digital amplitude modulation device comprising: a plurality of power amplifiers arranged in parallel and configured to amplify an input signal in accordance with ON control and stop output in accordance with OFF control; a compositor configured to composite signals output from the plurality of power amplifiers to generate a composite signal; a filter configured to suppress an unnecessary component of the composite signal generated by the compositor to generate an AM (Amplitude Modulation) signal in an RF (Radio Frequency) band; a measurement unit configured to measure a measurement value between the filter and a signal output terminal configured to output the AM signal in the RF band generated by the filter; a protection unit including a calculator formed from an analog circuit and configured to calculate an evaluation value based on the measurement value measured by the measurement unit, and a first processing unit formed from an analog circuit and configured to generate a first control signal for OFF-controlling the plurality of power amplifiers based on the calculated evaluation value; and a controller configured to ON-control and/or OFF-control the plurality of power amplifiers by referring to an amplitude level of a modulated signal, and upon receiving the first control signal, OFF-control the plurality of power amplifiers.