To provide a forward amplifier circuit for performing distortion compensation with high accuracy while simplifying the circuit and reducing power consumption by eliminating a control circuit such as a DSP and an element for control (variable phase shifter and variable attenuator).
An input signal which is branched to a sub line by a first branching means 10 and amplified by a second amplifying means 12b with a temperature characteristic matched to that of a first amplifying means 12a is combined with an input signal amplified by the first amplifying means 12a on a main line in an opposite phase to generate a distortion component signal, and the distortion component signal is combined with the input signal on the main line in an opposite phase to compensate distortion components. A fixed attenuating means 15 and a fourth amplifying means 17a are provided to attenuate on the main line a gain of a third amplifying means 17b for compensating losses that occur in the first branching means 10 and a second branching means 13 are provided.
Hiroshi Ochi
Sadao Matsumura
Isamu Kakiuchi