The present disclosure relates to a radio transmission or reception apparatus and a beam forming method thereof. The apparatus according to the present disclosure comprises: an array antenna for forming multiple beams having different directivities so as to transmit or receive signals through the multiple beams; a digital unit for synthesizing an orthogonal polarization pair so as to generate multi-beam signals for forming the multiple beams; and an RF unit for frequency-converting the multi-beam signals so as to output each of the frequency converted multi-beam signals to the array antenna.