DISTORTION COMPENSATING POWER AMPLIFYING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain a good distortion compensation effect up to the higher output power when distortion compensation for a power amplifying device is done by infusing the second harmonic. SOLUTION: A source-grounded FET (Field Effect Transistor) 12 generates the second harmonic of a fundamental harmonic for one branch signal branched by a branch circuit 10 bi-branching an input signal. A BPF (Band-Pass Filter) 13 extracts the generated second harmonic. An addition circuit 16 adds the second harmonic to the other branch signal of the branch circuit 10 for input to the input terminal of an FET 17. The output terminal of the FET 17 is connected to a termination circuit 18 ground-short-circuiting the second harmonic. The termination circuit 18 includes a coil and a capacitor connected in parallel to each other and almost opens the fundamental harmonic and almost short-circuits the second harmonic in observation from the output terminal of the FET 17. COPYRIGHT: (C)2006,JPO&NCIPI