Patent ID: 9306500
Filing Date: 2016-04-05
CPC Classification: H03F

Claim Text:
1. A cascode amplifier comprising: a first transistor having a gate to which a signal is input, a grounded source, and a drain; a second transistor having a gate, a source connected to the drain of the first transistor, and a drain; a load connected to the drain of the second transistor; a DC-DC converter supplying a supply voltage, which is variable according to output power, to the drain of the second transistor via the load; a first bias circuit supplying a voltage, which is a function of the supply voltage, to the gate of the second transistor; and a second bias circuit supplying a voltage, which is a function of the supply voltage, to the gate of the first transistor, wherein output voltage of the second bias circuit decreases with an increase of the supply voltage.