Power amplifier
A power amplifier includes: an amplifier having an input terminal and including an amplifying transistor having a threshold voltage; a transistor supplying a bias to the input terminal of the amplifier according to an on/off signal; a capacitor connected between the input terminal of the amplifier and a grounding point; a resistor connected between the input terminal of the amplifier and the grounding point, in parallel with the capacitor; and a diode connected in series with the resistor. The diode has a threshold voltage that is lower than the threshold voltage of the amplifying transistor.
1. A power amplifier comprising:
an amplifier having an input terminal and including an amplifying transistor having a threshold voltage;
a transistor supplying a bias to the input terminal of the amplifier according to an on/off signal;
a capacitor connected between the input terminal of the amplifier and a grounding point;
a resistor connected between the input terminal of the amplifier and the grounding point, in parallel with the capacitor; and
a diode connected in series with the resistor, wherein
the diode has a threshold voltage that is lower than the threshold voltage of the amplifying transistor, and
the diode turns off after the transistor turns off.
2. The power amplifier of claim 1 , wherein the amplifying transistor is a HBT and the diode is a Schottky diode.