Abstract: The bandwidth characteristics of subarray excited devices have important influence on the beam bandwidth and VSWR bandwidth of a planar array antenna. This paper analyses bandwidth characteristics of each subarray excited forms in common use in home and abroad and describes the designs and the calculations of some subarray excited forms. The phase bandwidth and VSWR bandwidth of some subarray excited forms are discussed and analyaed, and some related simulation results and experiment results are presented. This paper has also offered the design reference for engineering application.