Patent ID: 8659352

Claim:
A power amplifier comprising: a first amplifying element amplifying an input signal; a second amplifying element amplifying an output signal of the first amplifying element; a third amplifying element amplifying the input signal; a first switch connected between an output of the first amplifying element and an input of second amplifying element; a second switch connected between an output of the first amplifying element and an output of the third amplifying element; a third switch connected between an output of the first amplifying element and an output of the second amplifying element; a reference voltage generating circuit generating a reference voltage; a bias circuit supplying a bias current, based on the reference voltage and supplied to inputs of the first, second, and third amplifying elements; and a control circuit controlling the first, second and third switches and the reference voltage generating circuit, wherein, when the control circuit turns the first switch off and turns the second and third switches on, the control circuit stops the reference voltage generating circuit from generating the reference voltage.