In an embodiment method, a hybrid coupler comprises a first input receiving an analog signal, a second input receiving an additional analog signal phase shifted by 90° from the analog signal, and first and second outputs. The method comprises injecting into the second output a test signal having an initial test phase, iteratively generating a current test phase for the test signal, from the initial test phase to a final test phase equal to the initial test phase increased by at least one portion of one complete revolution, and, in each iteration, measuring the current peak value of the first output, and storing the current test phase and the current peak value as a maximum/minimum peak value if there is not a stored maximum/minimum peak value higher/lower than the current peak value, respectively, and determining a phase of the analog signal from the stored test phase.