Patent ID: 8917145
Filing Date: 2014-12-23
Classification: H03F

Abstract:
1. An amplifier circuit, comprising: an amplifying unit including at least one transistor; at least one first bias circuit unit including at least one resistor and connected to the at least one transistor; and at least one second bias circuit unit connected between an input terminal to which an input signal is applied and the at least one transistor so as to block an input signal having a frequency higher than a first frequency or having a frequency lower than a second frequency, wherein: the at least one transistor and the at least one resistor compose a negative feedback circuit preventing a thermal runaway of the at least one transistor, the at least one second bias circuit unit includes a capacitive element and an inductive element connected in series, and the resistor included in the at least one first bias circuit unit is connected to a node that is connected between the inductive element and the capacitive element included in the at least one second bias circuit unit.