Abstract: An amplifier circuit is comprising a first amplifier configured to receive a first signal, a second amplifier configured to receive a second signal, a third amplifier configured to receive a third signal, and a directional coupler. An output of the first amplifier is connected to a first port of the directional coupler, an output of the third amplifier is connected to a second port of the directional coupler, an output of the second amplifier is connected to a third port of the directional coupler, and a fourth port of the directional coupler is connected to an output of the amplifier circuit. The directional coupler is configured such that different proportions of output signals of the second and third amplifiers are coupled to the first port of the directional coupler.

Abstract: In one aspect, a power amplifier apparatus comprising a power amplifier (PA) and an adaptive controller is provided. The PA comprises at least one transistor and the adaptive controller is configured to control a bias voltage of the transistor based on a measured power efficiency of the PA and a measure output signal quality of the PA. In another aspect, a method of optimizing PA performance is provided. The PA comprises at least one transistor and the method includes initializing a bias voltage of the transistor, receiving measurements indicating a power efficiency and an output signal quality of the PA, evaluating the received measurements, calculating a new bias voltage for the transistor based on the evaluation, and applying the calculated new bias voltage to the transistor.

Abstract: In one aspect, a power amplifier apparatus comprising a power amplifier (PA) and an adaptive controller is provided. The PA comprises at least one transistor and the adaptive controller is configured to control a bias voltage of the transistor based on a measured power efficiency of the PA and a measure output signal quality of the PA. In another aspect, a method of optimizing PA performance is provided. The PA comprises at least one transistor and the method includes initializing a bias voltage of the transistor, receiving measurements indicating a power efficiency and an output signal quality of the PA, evaluating the received measurements, calculating a new bias voltage for the transistor based on the evaluation, and applying the calculated new bias voltage to the transistor.

Abstract: An amplifier arrangement (200) for amplifying input signals and a method for operating the amplifier arrangement are disclosed. The amplifier arrangement (200) comprises a main amplifier circuit (210) having an input and an output; a first (221) and second (222) auxiliary amplifier circuits each having an input and an output, wherein each of the first (221) and second (222) auxiliary amplifier circuits being selectively operable to operate in combination with the main amplifier circuit (210). The amplifier arrangement (200) further comprises a single hybrid coupler circuit (230) having a first port (221) being coupled to the output of the main amplifier circuit (210), a second port (232) being coupled to the output of the first auxiliary amplifier circuit (221), a third port (233) being coupled to the output of the second auxiliary amplifier circuit (222) and a fourth port (234) being coupled to the load (240) of the amplifier (200).

Abstract: An amplifier arrangement (200) for amplifying input signals and a method for operating the amplifier arrangement are disclosed. The amplifier arrangement (200) comprises a main amplifier circuit (210) having an input and an output; a first (221) and second (222) auxiliary amplifier circuits each having an input and an output, wherein each of the first (221) and second (222) auxiliary amplifier circuits being selectively operable to operate in combination with the main amplifier circuit (210). The amplifier arrangement (200) further comprises a single hybrid coupler circuit (230) having a first port (221) being coupled to the output of the main amplifier circuit (210), a second port (232) being coupled to the output of the first auxiliary amplifier circuit (221), a third port (233) being coupled to the output of the second auxiliary amplifier circuit (222) and a fourth port (234) being coupled to the load (240) of the amplifier (200).