The present invention relates to a 
beam steering system. The 
system includes an array of a plurality of antenna elements, each 
antenna element being electrically and mechanically controlled for steering a beam in a specific direction, and a 
millimeter wave subsystem quasi-optically integrated with a 3-dimensional 
beam steering device and an MMIC-type active circuit. The 
antenna element is controlled in real time by an electrical driving method so as to be moved in 2-dimensional space. That is, in the 3-dimensional 
system of the present invention, the beam is electrically controlled by a phase shifter, and each 
antenna element is physically moved by a mechanical driving mechanism. The 3-dimensional 
beam steering antenna and the associated devices are monolithically integrated on a substrate using MEMS technology, and the active circuit elements such as a mixer, a power 
amplifier (PA), a 
low noise amplifier (LNA), a VCO, etc. are integrated in an MMIC 
active array. The 3-dimensional beam steering device and the active MMIC circuit are integrated into one system by being interconnected using the quasi-optical technique. According to the present invention, shortcomings of the 
millimeter wave in that the SNR is low due to the low device output and 
high transmission loss in the 
free space can be overcome using the new 
RF transmission technique of 3-dimensional beam steering, and by introducing a micro antenna structure which is electrically and mechanically controlled such that 
wideband RF communication and 3-dimensional imaging is allowed in a Pico 
cell environment.