Front end module, FEM, circuitry, comprising: a hybrid coupler to generate a first antenna transmit signal and a second antenna transmit signal; and one or more tunable phase shifters (811, 821) to generate hybrid coupler input signals (816, 826) based at least partly on an FEM input signal (810, 820), wherein the hybrid coupler is adapted to generate the first antenna transmit signal based on a first summation that comprises a first hybrid coupler input signal and further comprises a second hybrid coupler input signal phase-shifted, by the hybrid coupler, according to a predetermined hybrid coupler phase shift, and wherein the hybrid coupler is adapted to generate the second antenna transmit signal based on a second summation that comprises the second hybrid coupler input signal and further comprises the first hybrid coupler input signal phase-shifted, by the hybrid coupler, according to the hybrid coupler phase shift, wherein the predetermined hybrid coupler phase shift is substantially 90 degrees, characterised in that: the FEM circuitry further comprises one or more tunable amplitude shifters (814, 815, 824, 825) to adjust an amplitude of the FEM input signal (810, 820) to generate the hybrid coupler input signals (816, 826), such that when the tunable amplitude shifters are configured to disable the second hybrid coupler input signal: the first antenna transmit signal comprises a first signal component of the FEM input signal and the second antenna transmit signal comprises a second signal component of the FEM input signal, wherein the second signal component is based on the first signal component phase-shifted by a phase shift of substantially 90 degrees. a hybrid coupler to generate a first antenna transmit signal and a second antenna transmit signal; and one or more tunable phase shifters (811, 821) to generate hybrid coupler input signals (816, 826) based at least partly on an FEM input signal (810, 820), wherein the hybrid coupler is adapted to generate the first antenna transmit signal based on a first summation that comprises a first hybrid coupler input signal and further comprises a second hybrid coupler input signal phase-shifted, by the hybrid coupler, according to a predetermined hybrid coupler phase shift, and wherein the hybrid coupler is adapted to generate the second antenna transmit signal based on a second summation that comprises the second hybrid coupler input signal and further comprises the first hybrid coupler input signal phase-shifted, by the hybrid coupler, according to the hybrid coupler phase shift, wherein the predetermined hybrid coupler phase shift is substantially 90 degrees, characterised in that: the FEM circuitry further comprises one or more tunable amplitude shifters (814, 815, 824, 825) to adjust an amplitude of the FEM input signal (810, 820) to generate the hybrid coupler input signals (816, 826), such that when the tunable amplitude shifters are configured to disable the second hybrid coupler input signal: the first antenna transmit signal comprises a first signal component of the FEM input signal and the second antenna transmit signal comprises a second signal component of the FEM input signal, wherein the second signal component is based on the first signal component phase-shifted by a phase shift of substantially 90 degrees. the FEM circuitry further comprises one or more tunable amplitude shifters (814, 815, 824, 825) to adjust an amplitude of the FEM input signal (810, 820) to generate the hybrid coupler input signals (816, 826), such that when the tunable amplitude shifters are configured to disable the second hybrid coupler input signal: the first antenna transmit signal comprises a first signal component of the FEM input signal and the second antenna transmit signal comprises a second signal component of the FEM input signal, wherein the second signal component is based on the first signal component phase-shifted by a phase shift of substantially 90 degrees.