Patent ID: 8564369

Claim:
A linear amplifier, comprising: an amplifier amplifying an input signal according to a difference in signal level between the input signal and a feedback signal; and a buffer buffering a signal amplified in the amplifier by a source follow method, suppressing a reduction in bandwidth of the signal, outputting the signal, and providing the bufferred signal to the amplifier as the feedback signal, wherein the buffer includes: a removing unit removing body effects of a transistor supplying a bias required for the source follow method; a controller controlling an output signal to be rail to rail swing amplified; a feedback providing unit providing preset first and second local feedback loops in a transfer path of a signal from the removing unit to suppress the reduction in bandwidth of the amplified signal; a bias unit supplying a bias required for the source follow method; a buffer unit buffering the amplified signal by the source follow method and suppressing the reduction in bandwidth of the amplified signal; and an output unit outputting the buffered signal from the buffer unit and providing the output signal to the amplifier as the feedback signal.