Abstract: A high power amplifier has a first balun propagating a half of an input signal to an in-phase output terminal, and also propagating a fourth of the input signal to first and second opposite-phase output terminals, the signal propagated to the first and second opposite-phase output terminals lagging 180 degrees behind the signal propagated to the in-phase output terminal; first and second power amplifier circuits connected to the first and second opposite-phase output terminals of the first balun and having the same characteristics;a third power amplifier circuit connected to the in-phase output terminal of the first balun and having output power substantially twice as much as the output power of the first or second power amplifier circuit; and a second balun having first and second opposite-phase input terminals for receiving the outputs of the first and second power amplifier circuits, having an in-phase input terminal for receiving the output of the third power amplifier circuit, combining the outputs of th

Abstract: A power amplifier that reduces intermodulation distortion generated by the amplifier while reducing the number of parts is provided. A power amplifier comprises a first balun, to which a combined signal combining two signals of different frequencies is inputted, and which outputs, based on the combined signal, the first and the second signal whose phase are opposite; a first amplifier that outputs the first amplified signal containing the differential frequency component comprising the difference of the frequencies of two signals from the first signal; a second amplifier that outputs the second amplified signal containing the component comprising the difference of the frequencies of two signals from the second signal; and a second balun that outputs the combined signal of the first and the second amplified signals. The component contained in the first and the second amplified signal are inputted via the second and the first amplifier, respectively, to reduce the component.

Abstract: A feedforward amplifier includes a power divider for dividing the input signal into first and second signals. The first signal is processed in a first path that includes, in sequence, a first vector adjuster, a main amplifier, a directional coupler and a delay circuit. The second signal is delayed in a second path that includes, in sequence, another delay circuit, a first power combiner and an auxiliary amplifier block. The first power combiner combines the first signal, by way of a coupling port from the directional coupler, with the second signal to provide a combined signal into the auxiliary amplifier block. The auxiliary amplifier block further divides the second signal into two divided signals, each having a respective non-overlapping frequency band. The two divided signals are respectively vector adjusted, amplified, and then recombined. The recombined signal is then recombined with the processed signal in the first path to provide the desired output signal.

Abstract: According to the configuration the present power splitter, it is possible to reduce the characteristic impedance of a transmission line constituting a directional coupler by setting the impedance of a first terminal pair constituted of an input port 7a and a second output port 7d of a 6-dB branch-line-shaped directional coupler 7 to a value smaller than a reference impedance Z0 (50 &OHgr; in general) and setting the impedance of a second terminal pair constituted of an isolation port 7b and a first output port 7c of the directional coupler 7 to Z0. Therefore, it is possible to increase the number of splits and reduce loss, as compared with conventional cases.

Abstract: A high power amplifier has a first balun propagating a half of an input signal to an in-phase output terminal, and also propagating a fourth of the input signal to first and second opposite-phase output terminals, the signal propagated to the first and second opposite-phase output terminals lagging 180 degrees behind the signal propagated to the in-phase output terminal; first and second power amplifier circuits connected to the first and second opposite-phase output terminals of the first balun and having the same characteristics; a third power amplifier circuit connected to the in-phase output terminal of the first balun and having output power substantially twice as much as the output power of the first or second power amplifier circuit; and a second balun having first and second opposite-phase input terminals for receiving the outputs of the first and second power amplifier circuits, having an in-phase input terminal for receiving the output of the third power amplifier circuit, combining the outputs of t

Abstract: A high power amplifier has a first balun propagating a half of an input signal to an in-phase output terminal, and also propagating a fourth of the input signal to first and second opposite-phase output terminals, the signal propagated to the first and second opposite-phase output terminals lagging 180 degrees behind the signal propagated to the in-phase output terminal; first and second power amplifier circuits connected to the first and second opposite-phase output terminals of the first balun and having the same characteristics; a third power amplifier circuit connected to the in-phase output terminal of the first balun and having output power substantially twice as much as the output power of the first or second power amplifier circuit; and a second balun having first and second opposite-phase input terminals for receiving the outputs of the first and second power amplifier circuits, having an in-phase input terminal for receiving the output of the third power amplifier circuit, combining the outputs of t

Abstract: A feed forward amplifier comprises a main amplifier 10 composed of a plurality of power amplifiers 8 and 9 combined in parallel. In addition to the plurality of power amplifiers, this feed forward amplifier includes a distortion detecting amplifier 25 for detecting the distortion components, having a distortion characteristic in a predetermined relationship with the distortion characteristic of the main amplifier. It also omits a distortion detecting power combiner 23 otherwise located after a main amplifier 10 and locates a delay circuit 21 before the main amplifier 10 to reduce losses occurring after the main amplifier 10 to improve the efficiency of the entire feed forward amplifier.

Abstract: The invention presents a high efficiency linear power amplifier of plural frequency bands reduced in the number of parts and elements, simplified in the circuit construction, and saved in the circuit space, and in FIG. 1, signals entering from a common input terminal 1 in frequency bands A and B are matched in both frequency bands A and B in a wide band matching network 2, amplified in a pre-amplifier 3, put into a common terminal 4a of a switch circuit 4, and the signal in frequency band A is put into a changeover terminal 4b, matched in a matching network 5 and amplified in a post-amplifier 6, and its output is matched in a post-matching network 7 and sent out into an output terminal 8, while, similarly, the signal in frequency band B is put into other changeover terminal 4c of the switch circuit 4, matched in a matching network 9, amplified in a post-amplifier 10, and its output is matched in a post-matching network 11 and is sent out into an output terminal 12.