An apparatus for radio frequency, RF, linearization of multiple amplifiers of a phased array, the apparatus comprising: a plurality of return paths configured to carry at least RF sample signals of a plurality of RF power amplifiers ; a plurality of phased array elements (702a-702n), wherein each phased array element of the plurality of phased array elements comprises: a variable gain RF power amplifier , corresponding to one of the plurality of RF power amplifiers ; a switch configured to connect a respective antenna element to a respective transmit path in a transmit phase and to connect the respective antenna element to a respective receive path in a receive phase; a directional coupler coupled between the variable gain RF power amplifier and the switch ; and a return side phase shifter , corresponding to a respective one of a plurality of return side phase shifters ; a hardware RF power combiner configured to combine the RF sample signals to generate a combined signal, wherein the plurality of return-side phase shifters are configured to adjust a phase shift of the RF sample signals such that the RF sample signals are phase aligned at the hardware RF power combiner; and a predistorter configured to predistort an input signal to generate a predistorted signal and configured to adapt predistortion coefficients for predistortion based at least partly on observations of a signal derived from the combined signal, wherein, during the transmit phase, for each of the plurality of phased array elements (702a-702n), the directional coupler is configured to provide a portion of transmitted power to the antenna element and another portion of the transmitted power is coupled to the return-side phase shifter to provide the RF sample signals. a plurality of return paths configured to carry at least RF sample signals of a plurality of RF power amplifiers ; a plurality of phased array elements (702a-702n), wherein each phased array element of the plurality of phased array elements comprises: a variable gain RF power amplifier , corresponding to one of the plurality of RF power amplifiers ; a switch configured to connect a respective antenna element to a respective transmit path in a transmit phase and to connect the respective antenna element to a respective receive path in a receive phase; a directional coupler coupled between the variable gain RF power amplifier and the switch ; and a return side phase shifter , corresponding to a respective one of a plurality of return side phase shifters ; a variable gain RF power amplifier , corresponding to one of the plurality of RF power amplifiers ; a switch configured to connect a respective antenna element to a respective transmit path in a transmit phase and to connect the respective antenna element to a respective receive path in a receive phase; a directional coupler coupled between the variable gain RF power amplifier and the switch ; and a return side phase shifter , corresponding to a respective one of a plurality of return side phase shifters ; a hardware RF power combiner configured to combine the RF sample signals to generate a combined signal, wherein the plurality of return-side phase shifters are configured to adjust a phase shift of the RF sample signals such that the RF sample signals are phase aligned at the hardware RF power combiner; and a predistorter configured to predistort an input signal to generate a predistorted signal and configured to adapt predistortion coefficients for predistortion based at least partly on observations of a signal derived from the combined signal, wherein, during the transmit phase, for each of the plurality of phased array elements (702a-702n), the directional coupler is configured to provide a portion of transmitted power to the antenna element and another portion of the transmitted power is coupled to the return-side phase shifter to provide the RF sample signals. <EOS>