I am using the nrf51822-QFAC-R in an application where the realization of the antenna is very challenging, and I expect to have an antenna |S11|=-1dB, with variations of the impedance depending on the final use case, so I can not design a matching network to match this impedance to the recommended 15+j85Ohm, as each final application would have different impedance. If the impedance seen at ports ANT1 and ANT2 is VERY different from the target one, is there any point in which the PA just stops to work because of the reflection?
From the communications range point of view I am not worried, as the communication has to be done in a range of 10cm aprox, so even if most of the power is lost because of mismatching it will still work, but I am afraid that the PA is not able to work with really bad impedances. Is that the case?