This work describes the design and manufacturing of a 4-bit phase shifter for an active electronically scanned array (AESA) in Ka-band. This component is mandatory for electronic scanning. The equation linking the radiating pattern to the applied phase gradient will be detailed. The principle of the phase shift will be presented and the simulations and measurements will be done for all phase states. Finally, the phase shifter will be used again in a projection for 8x8 antenna array. A comparison between a perfect model and a real model will be explained.