FIELD: radio engineering.
SUBSTANCE: invention relates to the field of radio engineering and can be applied in radio transmitting apparatuses to create power amplifiers with a low level of out-band emissions used in radio communication and television and radio broadcasting. To realise the technical result, the distortion signal is isolated by subtracting the input signal from the output signal, and the functional dependence of these distortions on the input signal is determined. Using this functional dependence in the form of a separate pre-distortion function, a compensating signal is synthesised, admixed to the input of the power amplifier. A look-up table (LUT) can be used as pre-distortion functions. The apparatus comprises a control circuit (3) for mutual alignment of the amplitudes and phases of the input and output signals, an adder (4) for isolating the distortion signal, a unit for calculating the parameters of the pre-distortion function (5), a switch (6), a pre-distortion function unit (7), at the output whereof a compensating signal is synthesised, supplied to the input of the power amplifier (2) after phase alignment (in unit 8), thereby compensating for distortions thereof. For power amplifiers with the memory effect, the parameters of the pre-distortion function are calculated over the entire memory interval.
EFFECT: reduction in the level of residual distortion at the output of the power amplifier.
6 cl, 3 dwg
