To provide a method and a system for the multi-beam phased array antenna transmission where the effect of space limitation of a limited area of a transmitter as the higher transmission frequency is adopted by generating an RF transmission signal properly phase-shifted based on a heterodyne effect.

An RF signal with an intermediate frequency no being a final frequency of transmission includes a signal frequency for a beam shaping network providing an input to a multiplexed power distributer 20. The power distributer 20 provides the output of a phase shift signal to each input section of many multiplex couplers 22. The output of each coupler 22 is fed to a mixing device 23, which uses a proper local oscillator signal to shift an input frequency to a high frequency. The output of the mixer 23 is fed to each power amplifier 26 and its output is sent to a radiation element. A low primary frequency is used for each power distributer 20 and a coupler stage and then conventional size components not small sized elements relating to a millimeter wave circuit are used for each power distributer 20 and the coupler stage.