The phase properties of a 90 degree hybrid coupler can be used to great advantage in microwave circuits. For
example in a balanced microwave amplifier the two input stages are fed through a hybrid coupler. The FET device normally
has a very poor match and reflects much of the incident energy. However, since the devices are essentially identical the
reflection coefficients from each device are equal. The reflected voltage from the FETs are in phase at the isolated port and
are 180E different at the input port. Therefore, all of the reflected power from the FETs goes to the load at the isolated port
and no power goes to the input port. This results in a good input match (low VSWR).