This paper presents the design and implementation of a 19.5 GHz active phase shifter for beamforming. The proposed circuit is based on an original architecture using an injection-locked voltage-controlled oscillator (ILVCO) associated with a polyphase filter followed by a phase selection circuit and its sign. From a 1.3 V supply voltage, the proposed circuit was designed to obtain a phase shift range of 360°. This phase shifter is synthesized using the phase selection circuit (PS) for coarse adjustment in the steps of 90° and the injection-locked VCO for a fine-tuning adjustment between ±45°. The circuit consumed a total current of 20.47 mA with a chip size of 1.51 mm2 including the pads and it is integrated in a BiCMOS SiGe:C 0.13 µm process.