| 摘要 |
PURPOSE: A power amplification bias circuit is provided to improve power efficiency by adding a circuit capable of controlling a bias according to a power level of an outer signal to control current supplied to a base of an amplifying part. CONSTITUTION: A power amplification bias circuit comprises a bias supplying part(12) included with a first transistor(Q11) supplying a bias to a base(11) of an amplifying part, a voltage source part(13) supplying a voltage source to the bias supplying part(12), a bias fixing part(14) constantly keeping the bias of the bias supplying part(12), and a bias controlling current source part(15) connected to the bias fixing part(14) for controlling the bias. The bias controlling current source part(15) further includes a voltage source(Vc) controlling a bias current through an ON/OFF operation according to an outer signal and a resistance(R11) controlling a base current of the amplifying part.
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