The present disclosure provides a transmission mechanism, wherein the transmission mechanism comprises a driving shaft; and a stopper assembly, the stopper assembly including: a base, a surface of the base forming a first thread; and a rotating component, the rotating component being positioned on the driving shaft and can rotate with the driving shaft, and the surface of the rotating component forms a second thread matching the first thread, wherein ,at least one of the base and the rotating component is configured with a stopper; when the driving shaft rotates, the rotating component rotates with the driving shaft and slides relative to the base through an engagement of the first thread and the second thread; when the stopper resists the base or the rotating component, a relative sliding between the base and the rotating component stops. Since the stop assembly uses fewer parts and the structural fit gap is correspondingly reduced, the initial phase shift position of the phase shifter can be calibrated more accurately using this stop assembly, thereby improving the adjustment efficiency of the phase shifter.