An active slide screw tuner uses the forward injection technique, also called Gamma Boosting Unit (GBU) cascaded with a passive impedance tuner in the same slabline and housing. The GBU samples a portion of the forward travelling signal, adjusts its phase, amplifies it, adjusts its amplitude (attenuation) and couples it back, in reverse direction into the main signal path. In the present active tuner technique as is herein implemented, the horizontal and vertical movement of the forward coupler through remote control in a tuner-type carriage and vertical axis, eliminates the need of a separated phase shifter and attenuator, which makes the solution better, simpler and more effective.