Abstract: A dual band power amplifier includes a power amplifier, a first matching circuit, a first auxiliary circuit, a second matching circuit, and a second auxiliary circuit. The power amplifier has inputs and outputs, and configured to amplify input signals at a first and second frequency. The first matching circuit electrically connected to the output of the power amplifier and configured to match a load impedance to an output impedance at the first frequency. The first matching circuit and the first auxiliary circuit configured to match the load impedance to the output impedance at the second frequency. The second matching circuit electrically connected to the input of the power amplifier and configured to match a source impedance to an input impedance at the first frequency. The second matching circuit and the second auxiliary circuit configured to match the source impedance to the input impedance at the second frequency.

Abstract: A Doherty amplifier (300) is provided, it comprises: a main amplifier (301) and a peak amplifier (302); a first microstrip (303) with ?/4 electric length connected between the main amplifier and the peak amplifier; a second microstrip (304) with ?/4 electric length connected between a junction of outputs of the peak amplifier and the main amplifier, and an output terminal (306); at least a tuner (305) for adjusting radius of VSWR circle of the main amplifier and connected, in series with the first microstrip (303), between the main amplifier (301) and the peak amplifier (302) based on input signal power. The hack-off power level efficiency is increased by enlarge the VSWR radius with the new Doherty structure.

Abstract: A Doherty amplifier (300) is provided, it comprises: a main amplifier (301) and a peak amplifier (302); a first microstrip (303) with ?/4 electric length connected between the main amplifier and the peak amplifier; a second microstrip (304) with electric length connected between a junction of outputs of the peak amplifier and the main amplifier, and an output terminal (306); at least a tuner (305) for adjusting radius of VSWR circle of the main amplifier and connected, in series with the first microstrip (303), between the main amplifier (301) and the peak amplifier (302) based on input signal power. The hack-off power level efficiency is increased by enlarge the VSWR radius with the new Doherty structure.