A radar antenna assembly includes a microstrip patch, a hybrid coupler, a phase shifter, and a power divider. The microstrip patch is configured to emit a radar signal. The radar signal is characterized by a transmitted polarization of the radar signal. The transmitted polarization is influenced by a first transmit signal received at a first port of the microstrip patch and a second transmit signal received at a second port of the microstrip patch. The hybrid coupler is configured to orthogonally combine a first input signal and a second input signal to output the first transmit signal and the second transmit signal. The phase shifter is operable to vary the phase of the second input signal relative to the first input signal. The power divider is configured to divide unequally a source signal so the amplitudes of the first input signal and the second input signal are substantially equal.