Abstract: A detuned composite amplifier includes a nonlinear drive function (22) that has a phase that varies with the composite amplifier output voltage amplitude. The nonlinear drive function (22) is configured to transform the output voltage transition point of the prior art into an extended output voltage transition region to increase the efficiency of the composite amplifier.

Abstract: A PAMELA-type of composite power amplifier is configured in such a way that a single power amplifier is operated at low output voltage amplitudes by prohibiting a pair of outphasing power amplifiers to produce any current. Preferably, at output voltage amplitudes above the maximum voltage of the single power amplifier is to be reached, the pair of outphasing power amplifiers is taken into operation providing currents phase shifted by substantially 180 degrees. When also the outphasing power amplifiers reach their maximum voltages, an outphasing operation is performed.

Abstract: A multiple input multiple output power amplifier system includes multiple main amplifiers for amplifying corresponding independent input signals. A common control unit forms a composite signal from the independent input signals. The composite signal is amplified by a peaking amplifier and forwarded to an output network where main amplifier output signals are combined with amplified composite signals into multiple power amplifier output signals.

Abstract: A composite amplifier comprises several Chireix pairs (PA11, PA12; PA21, PA22) of power amplifiers connected to a common load. Means (21) are provided for driving each Chireix pair by drive signals having amplitude dependent phase over at least a part of the dynamic range of the composite amplifier . These parts are preferably different for different pairs.

Abstract: An adaptive predistortion arrangement includes means (26, 40, 42, 44, 46) for up-converting a baseband signal (S1) into an intermediate frequency signal (S12) having frequency aliazing and means (18, 20, 220, 24, 26) for down-converting a radio frequency signal (S4) into an intermediate frequency signal (S7) having the same frequency aliazing as the up-converted baseband signal. An adapter (34) adapts predistortion parameters to keep the up-converted baseband signal equal to the down-converted radio frequency signal.

Abstract: A radio transmitter with IQ-modulator error compensation includes a homodyne observation receiver (42) producing a first real baseband (S5) signal from a real radio frequency signal (S2). A real-value extracting element (44) and a down-sampler (46) convert a complex baseband signal (S1) into a second real baseband signal. An adapter (40) determines parameters controlling an IQ-error compensator (12) by minimizing the error between the two real baseband signals. In a preferred embodiment he transmitter also includes a phase shifter (56) providing three different phase shifts to compensate for the fact that the homodyne observation receiver produces a real and not a complex signal.

Abstract: A composite power amplifier structure includes a first power amplifier configured as an auxiliary amplifier of a Doherty amplifier and connected to an output node and an even number of further power amplifiers configured into at least one Chireix pair connected to the same output node. The Chireix pairs are driven at least partially in outphasing modes and the first power amplifier is driven in the same manner as the auxiliary amplifier of a Doherty amplifier.

Abstract: A PAMELA-type of composite power amplifier is configured in such a way that a single power amplifier is operated at low output voltage amplitudes by prohibiting a pair of outphasing power amplifiers to produce any current. Preferably, at output voltage amplitudes above the maximum voltage of the single power amplifier is to be reached, the pair of outphasing power amplifiers is taken into operation providing currents phase shifted by substantially 180 degrees. When also the outphasing power amplifiers reach their maximum voltages, an outphasing operation is performed.

Abstract: A transmitter comprises a device (20) for frequency up-conversion of a communication signal having at least two consecutive frequency conversion stages, a power amplifier (27) for amplifying the output signal therefrom for obtaining a transmission signal and means (29) for extracting the transmission signal. It also has a device for frequency down-conversion of said extracted transmission signal to the same frequency as the communication signal before said up-conversion for creating a feedback signal. Said two devices use the same local oscillators (25, 26). The transmitter also has means for signal parameter adaptation of the communication signal on basis of the feedback signal for obtaining a desired character of the transmission signal.

Abstract: A composite power amplifier structure includes a first power amplifier (PAN+1) configured as an auxiliary amplifier of a Doherty amplifier and connected to an output node and an even number of further power amplifiers configured into at least one Chireix pair (PA 1, 1+PA 1,2 . . . PA N, 1 +PA N,2) connected to the same output node. The Chireix pairs are driven (40) at least partially in outphasing modes and the first power amplifier is driven (40) in the same manner as the auxiliary amplifier of a Doherty amplifier.

Abstract: A composite amplifier comprises several Chireix pairs (PAII, PAI2; PA21, PA22) of power amplifiers connected to a common load. Means (21) are provided for driving each Chireix pair by drive signals having amplitude dependent phase over at least a part of the dynamic range of the composite amplifier . These parts are preferably different for different pairs.

Abstract: A transmitter comprises a device (20) for frequency up-conversion of a communication signal having at least two consecutive frequency conversion stages, a power amplifier (27) for amplifying the output signal therefrom for obtaining a transmission signal and means (29) for extracting the transmission signal. It also has a device for frequency down-conversion of said extracted transmission signal to the same frequency as the communication signal before said up-conversion for creating a feedback signal. Said two devices use the same local oscillators (25, 26). The transmitter also has means for signal parameter adaptation of the communication signal on basis of the feedback signal for obtaining a desired character of the transmission signal.