The mode features of an ideal-gap open-ring microstrip antenna

A rigorous analysis of the features of the modes of an ideal-gap open-ring (closed ring with a cross cut) printed microstrip antenna is presented. General expressions for its radiation field are derived by using the cavity model, trigonometric identities, and the properties of the cylindrical functions. The solution and the computed results for the radiation patterns and the field distributions for the even and odd modes are presented. The solutions for the even modes are the same as those for the closed-ring printed microstrip antenna. The results for the radiation patterns and other antenna characteristics for the odd modes indicate the superiority in the radiation properties of the ideal-gap open ring when excited in the TM/sub 12/ mode over those of a closed ring.<
>