Patent ID: 7649412
Filing Date: 2010-01-19
Classification: H03F

Abstract:
1. A high efficiency amplifier comprising: an input splitting circuit for splitting an input signal into first and second paths; a carrier amplifier connected to the first path; a peak amplifier connected to the second path; an impedance converting circuit connected to an output combining point of the first and second paths; a first phase line connected between an impedance reference point at an output side of said carrier amplifier and the output combining point; a second phase line connected between said input splitting circuit and said peak amplifier; and a third phase line connected between an impedance reference point at an output side of said peak amplifier and the output combining point, wherein when a level of the input signal is small, an electrical length of said first phase line and an electrical length of said third phase line are set in a manner that impedance seen by looking into an output side from the impedance reference point at the output side of said carrier amplifier is made 2R+α (where R is a load resistance and α is positive), and an electrical length of said second phase line is set at a difference between the electrical length of said first phase line and the electrical length of said third phase line.