A Precise Method of Phase Shift Measurement FOP Large Microwave System

Presented in this paper is a precise approach of phase shift measurement for large microwave system, i.e. dual (or four) cables phase shift measurement method. This method overcomes two disadvantages of the modulated reflective wave method, and eliminates the error arising from phase variation due to moving RF cable, as the basic phase shift measurement methods are used for measuring large microwave system. Particularly, it can be used for precisely measuring phase shift in the environme-nt with many obstacles, and the accuracy up to 1° can be obtained. Finaly, this paper analyzes main error factors and points out something needing attention.