The present disclosure provides a phase shifter including: a first substrate and a second substrate. The first substrate includes a reference electrode and a signal electrode, and the signal electrode includes a main structure and multiple branch structures. The second substrate includes multiple patch electrodes, and the multiple patch electrodes are arranged in a one-to-one correspondence with the multiple branch structures to form multiple variable capacitors. The phase shifter has a first region, and a second region and a third region which are respectively provided on two sides of the first region; and for any two of variable capacitors located on a same side of the first region, an overlap area of patch electrode and branch structure of a variable capacitor close to the first region is greater than or equal to that of a variable capacitor away from the first region.