The TRF3704 does not specify phase and amplitude imbalance independently. Instead, there is a spec for sideband rejection vs. frequency in the datasheet.  Sideband rejection is a parameter that combines the effect of amplitude and phase imbalance and does impact EVM% measurements for ZIF applications.  The SBS spec for the TRF3704 is around 40 dB which roughly corresponds to 0.5 degree phase imbalance or less and 0.1 dB of amplitude imbalance or less.